The Neurosurgical Outcome of Pediatric Cushing’s Disease in a Single Center From China: A 20-Year Experience

Objective: Pediatric Cushing’s disease (CD) is exceptionally rare and poses significant diagnostic and therapeutic challenges. This study aimed to review the diagnostic features and to evaluate the long-term surgical outcomes of transsphenoidal surgery (TSS) in Pediatric CD patients at a single tertiary center in China over two decades.

Methods: A retrospective analysis included 22 pediatric CD patients (10 male, 12 female; mean age 15.8 ± 2.5 years) who underwent TSS between 2002 and 2022. Diagnosis was established through a multidisciplinary protocol involving standardized biochemical testing (LDDST, HDDST), bilateral inferior petrosal sinus sampling (BIPSS) with desmopressin stimulation (n=19), and high-resolution pituitary MRI. Microscopic TSS (MTSS) was performed before 2016 (n=11) and endoscopic TSS (ETSS) thereafter (n=11). Surgical strategy was guided by MRI and BIPSS findings. Immediate remission was defined as a postoperative serum cortisol nadir <5 μg/dL or normal 24-h urinary free cortisol (UFC). Recurrence was defined as the reappearance of hypercortisolism after remission. Mean follow-up was 29.4 months (range 2-129).

Results: MRI identified the adenoma in 18/22 patients (81.8%; 16 microadenomas, 2 macroadenomas). BIPSS indicated lateralization in 14/19 patients (73.7%), with concordance between BIPSS and MRI lateralization in 57.9% (11/19) of cases. Immediate postoperative remission was achieved in 20 patients (90.9%). The two non-remitters (one macroadenoma, one MRI- and pathology-negative) received additional therapies. Among the 20 patients with initial remission, 2 (10.0%) developed recurrence (one microadenoma, one MRI-negative) during follow-up. The sustained long-term remission rate was 81.8% (18/22).

Conclusion: Transsphenoidal surgery represents a highly effective first-line treatment for pediatric CD, achieving high rates of immediate (90.9%) and long-term remission (81.8%) in a specialized center. A meticulous diagnostic approach incorporating BIPSS is crucial, particularly for MRI-negative cases. While recurrence occurred in a minority of patients, primarily those with microadenomas, durable disease control is attainable for the majority with appropriate surgical management. The transition to endoscopic techniques was feasible and effective.

Introduction

Cushing’s disease (CD), caused by excessive ACTH secretion from a pituitary corticotroph adenoma, is a rare disorder with an estimated prevalence of approximately 10 cases per 100,000. Its incidence is even lower in children, representing about 5% of adult cases (1). CD accounts for 75-80% of Cushing’s syndrome in pediatric patients (23). Clinical manifestations include weight gain, facial rounding (“moon facies”), hypertension, fatigue, and pubertal arrest. If untreated, pediatric CD can severely impair quality of life and lead to significant morbidity and mortality.

Diagnosis of pediatric CD is frequently delayed due to atypical symptoms and remains significantly challenging for pediatricians and pediatric endocrinologists (4). It relies on standardized biochemical evaluation and neuroimaging. Transsphenoidal pituitary surgery (TSS), encompassing both microscopic and endoscopic approaches, remains the preferred treatment for pediatric CD. However, as the majority of pituitary adenomas in pediatric CD are microadenomas or radiologically occult, TSS poses significant technical challenges for neurosurgeons (5).

Here, we present a review of the diagnostic features and surgical outcomes of 22 pediatric CD patients treated at a single center in China over a 20-year period.

Patients and methods

Between 2002 and 2022, 519 patients underwent TSS for CD performed by a single neurosurgical team in the Department of Neurosurgery, Ruijin Hospital. Twenty-six patients aged 18 years or younger were initially identified as pediatric; four were excluded due to incomplete data or insufficient follow-up. Clinical features of the remaining 22 pediatric patients (10 male, 12 female) were retrospectively reviewed. Mean age at surgery was 15.8 ± 2.5 years (range 9-18), and mean symptom duration prior to diagnosis was 32.0 ± 30.8 months (range 3-108). Mean BMI was 26.4 ± 6.4 (range 18.0-39.7) (Table 1). Presenting symptoms included weight gain (18/22), acne (13/22), hirsutism (12/22), moon facies (18/22), striae (19/22), central obesity (10/22), pubertal delay or arrest (4/22), irregular menses (3/12 females), headaches (3/22), visual deficits (2/22), hypertension (7/22), and type 2 diabetes mellitus (2/22) (Table 2).

Table 1

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Table 1. The demographic information of 22 patients at diagnosis of CD.

Table 2

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Table 2. Clinical signs and symptoms of 22 patients at diagnosis of CD.

Diagnosis of CD was confirmed by a multidisciplinary team comprising radiologists, endocrinologists, interventional radiologists, pediatricians, and neurosurgeons. Clinical manifestations, plasma cortisol circadian rhythm, low-dose dexamethasone suppression test (LDDST, 2 mg dexamethasone), and high-dose dexamethasone suppression test (HDDST, 8 mg dexamethasone) were assessed by pediatricians or endocrinologists. Following the 2mg LDDST, the 48-hour serum cortisol level exceeded 1.8 μg/dL, indicating inadequate suppression. In contrast, after the 8mg HDDST, the 48-hour cortisol level was suppressed to <50% of baseline, demonstrating significant suppression. Bilateral inferior petrosal sinus sampling (BIPSS) with or without desmopressin (DDAVP) stimulation was performed by experienced interventional radiologists. Samples were immediately placed on ice after collection. All biochemical analyses were conducted in a College of American Pathologists-accredited laboratory (No. 7217913).

Preoperative pituitary magnetic resonance imaging (MRI) was performed at 1.5 T or 3.0 T in all patients. T1-weighted and T2-weighted spin-echo images were obtained in coronal and sagittal planes (2-mm slice thickness) before and after gadolinium injection. A dynamic coronal sequence was also acquired within 2 minutes post-injection (Table 3).

Table 3

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Table 3. Preoperative endocrinological evaluation and neuroimaging results of 22 patients at diagnosis of CD.

The same surgical team performed TSS on all patients using a mononostril approach. Microscopic TSS (MTSS) was utilized in 11 patients treated before 2016, while endoscopic TSS (ETSS) was employed in the subsequent 11 patients. For patients with concordant MRI-identified adenomas and BIPSS lateralization, exploration focused on the imaging-identified region, and a rim of pituitary tissue surrounding the tumor cavity was resected. If the tumor involved the cavernous sinus (CS), the inner CS wall was also inspected/explored. If BIPSS lateralization conflicted with MRI findings, the pituitary side indicated by BIPSS was explored first. For MRI-negative tumors, exploration commenced on the side with higher ACTH levels on BIPSS (when available) and proceeded to complete gland inspection. If no adenoma was identified intraoperatively, approximately half of the gland was resected, guided by BIPSS results.

Immediate remission was defined as a postoperative serum cortisol nadir <5 μg/dL or normal 24-hour UFC. Recurrent hypercortisolism was defined as the reappearance of biochemical hypercortisolism after a period of hypocortisolism or clinical adrenal insufficiency. The concordance of BIPSS lateralization with MRI localization refers to whether the tumor side indicated by BIPSS corresponds to the tumor side identified on MRI.

Patients were followed in the outpatient clinic at regular intervals. If endocrine evaluations were performed at local hospitals, results were communicated to the authors via WeChat. Mean follow-up duration was 29.4 months (range 2–129 months).

Results

Preoperative plasma cortisol levels measured at three time points were: mean 28.10 μg/dL at 8:00 AM (range 14.70-125.62 μg/dL), 22.39 μg/dL at 4:00 PM (range 6.4-79.44 μg/dL), and 20.62 μg/dL at midnight (range 11.9-72.25 μg/dL). Mean preoperative plasma ACTH level at 8:00 AM was 95.21 pg/mL (range 12.51-272.6 pg/mL), and mean 24-hour UFC was 979.18 μg/24h (range 119.20-7669.48 μg/24h). HDDST was positive in 19/22 patients. BIPSS with DDAVP was performed in 19 patients, demonstrating lateralization in 14 patients (4/14 left, 10/14 right).

MRI localized an adenoma in 18/22 patients (81.8%), comprising 16 microadenomas and 2 macroadenomas. Tumor location on MRI was: right sellar (n=5), left sellar (n=8), and central sellar (n=5). Concordance between BIPSS lateralization and MRI localization was 57.89% (11/19).

Immediate postoperative remission was achieved in 20 patients (90.9%). The two patients without immediate remission (Case 2: macroadenoma; Case 6: MRI- and pathology-negative) received additional treatments (Case2: gamma knife radiosurgery; Case 6: ketoconazole). Among the 20 patients with initial remission, 2 (10.0%) experienced recurrence (Case 3: microadenoma; Case 10: MRI-negative). Case3 received pasireotide after recurrence; Case 10 underwent repeat TSS, which did not achieve remission. Subsequent gamma knife treatment also ultimately failed. Ketoconazole therapy was then initiated. The sustained long-term remission rate for the cohort was 81.8% (18/22).

In these cases, intraoperative bleeding was controlled in all cases, and no patient required transfusion. Case 10 experienced a CSF leak following repeat transsphenoidal surgery (TSS). All patients who achieved postoperative remission were administered cortisone replacement therapy. The requirement for levothyroxine replacement differed between groups: one child in the ETSS group (1/11) versus five patients in the MTSS group (5/11). For diabetes insipidus, oral desmopressin was administered to three patients in the ETSS group and two in the MTSS group (Table 4).

Table 4

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Table 4. The neurosurgical outcome and follow-up results of 22 patients of CD.

Discussion

This 20-year single-center experience represents one of the largest reported cohorts of surgically managed pediatric Cushing’s disease patients. Our findings demonstrate that transsphenoidal surgery (TSS), whether microscopic (MTSS) or endoscopic (ETSS), is a highly effective first-line treatment for pediatric CD, achieving an immediate remission rate of 90.9% and a sustained long-term remission rate of 81.8%.

The diagnostic complexity of pediatric CD is highlighted by the significant diagnostic delay observed (mean 32.0 months) and the occurrence of MRI-negative cases (4/22, 18.2%). This aligns with established literature emphasizing the challenges of pediatric CD diagnosis stemming from its rarity, atypical presentation, and the high proportion of microadenomas or radiologically occult tumors (3468). Our adherence to a rigorous multidisciplinary diagnostic protocol, incorporating standardized biochemical testing (LDDST, HDDST), BIPSS with DDAVP stimulation (performed in 19/22), and high-resolution dynamic pituitary MRI, reflects current best practices for confirming ACTH-dependent Cushing’s syndrome and tumor localization. The moderate concordance rate (57.89%) between BIPSS lateralization and MRI localization underscores their complementary roles, particularly in cases with equivocal imaging. BIPSS remains critical for guiding surgical exploration in MRI-negative or discordant cases, as evidenced by its use in our decision-making algorithm (910).

Our immediate remission rate (90.9%) compares favorably with contemporary pediatric CD surgical series, which typically report rates between 70% and 98% (1381113). The two immediate surgical failures occurred in patients with a macroadenoma (Case 2) or an MRI- and pathology-negative diagnosis (Case 6), profiles consistently associated with lower remission rates. The long-term remission rate of 81.8% (18/22) is robust, although the recurrence rate of 10% (2/20 initially remitted patients) merits attention. Both recurrences arose in patients with microadenomas, one of whom was MRI-negative (Case 10). This recurrence rate falls within the reported range (5-30%) for pediatric CD and reinforces the need for lifelong endocrine surveillance (11415). The relatively short mean follow-up (29.4 months) suggests that the true recurrence rate might be higher with extended observation, representing a limitation of this study.

Our experience reflects the evolution of surgical technique, with a transition from MTSS to ETSS after 2016. While the cohort size and follow-up duration preclude definitive conclusions regarding the comparative efficacy of MTSS versus ETSS in this specific pediatric population, both techniques yielded high success rates. In our group, no significant differences exist in remission or recurrence rates. However, regarding complications, ETSS demonstrates a lower incidence of hypopituitarism compared to MTSS, while the incidence of diabetes insipidus is similar. It should be noted, however, that this comparison remains limited by the small number of reported cases. The endoscopic approach offers theoretical advantages, such as wider panoramic visualization potentially aiding in the identification of small or laterally extending microadenomas, which are common in children. Larger, prospective studies with longer follow-up are warranted to directly compare outcomes between these surgical modalities in pediatric CD.

The spectrum of clinical manifestations observed (e.g., weight gain, moon facies, striae, hypertension, pubertal arrest/delay) demonstrates the profound multisystem impact of hypercortisolism in children. The notable prevalence of metabolic complications like hypertension (7/22) and type 2 diabetes mellitus (2/22), even in this young cohort, highlights the urgency of timely diagnosis and effective intervention to mitigate long-term morbidity (51618).

Limitations

This study shares the limitations inherent to retrospective, single-center designs. The modest sample size, though substantial for this rare condition, limits statistical power for subgroup analyses, such as rigorous comparison of MTSS vs. ETSS outcomes or identification of specific predictors of failure/recurrence. The mean follow-up period is relatively short for a disease with potential for late recurrence, long-term remission rates may be lower than reported, and the study could not capture long-term complications of TSS, particularly those affecting growth and development in pediatric patients. Detailed data on specific postoperative complications (e.g., diabetes insipidus, hypopituitarism) and pituitary function during follow-up would provide a more comprehensive assessment of treatment sequelae but were not the primary focus of this outcome report.

Conclusion

Despite the inherent diagnostic and therapeutic challenges of pediatric Cushing’s disease, transsphenoidal surgery performed in a specialized center achieves high rates of immediate and sustained remission. Our results support the efficacy of TSS as the primary treatment modality. A meticulous multidisciplinary diagnostic approach, including BIPSS when indicated, is crucial for success, particularly in MRI-negative cases. While recurrence remains a concern necessitating vigilant long-term follow-up, the majority of children with CD can attain durable disease control with appropriate surgical management. The transition to endoscopic techniques proved safe and effective, warranting further investigation in larger pediatric cohorts with extended follow-up.

Data availability statement

The original contributions presented in the study are included in the article/supplementary material. Further inquiries can be directed to the corresponding authors.

Ethics statement

The studies involving humans were approved by The ethics committee of Ruijin hospital. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study. Written informed consent was obtained from the individual(s), and minor(s)’ legal guardian/next of kin, for the publication of any potentially identifiable images or data included in this article.

Author contributions

BW: Methodology, Writing – original draft. HZ: Conceptualization, Data curation, Formal Analysis, Writing – original draft. TS: Methodology, Project administration, Writing – review & editing. JR: Data curation, Formal Analysis, Writing – original draft. QS: Resources, Supervision, Writing – review & editing. YS: Supervision, Writing – review & editing. LB: Supervision, Writing – review & editing.

Funding

The author(s) declare that no financial support was received for the research and/or publication of this article.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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The author(s) declare that no Generative AI was used in the creation of this manuscript.

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Keywords: Cushing’s disease, pediatric, transsphenoidal surgery, surgical outcome, surgical strategy

Citation: Wang B, Zhang H, Su T, Ren J, Sun Q, Sun Y and Bian L (2025) The neurosurgical outcome of pediatric Cushing’s disease in a single center from China: a 20-year experience. Front. Endocrinol. 16:1663624. doi: 10.3389/fendo.2025.1663624

Received: 10 July 2025; Accepted: 22 August 2025;
Published: 03 September 2025.

Edited by:

Sadishkumar Kamalanathan, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), India

Reviewed by:

Aleksandra Zdrojowy-Wełna, Wroclaw Medical University, Poland
Medha Bhardwaj, Mahatma Gandhi University of Medical Sciences Technology, India

Copyright © 2025 Wang, Zhang, Su, Ren, Sun, Sun and Bian. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Yuhao Sun, syh11897@rjh.com.cn; Liuguan Bian, Blg11118@rjh.com.cn

These authors have contributed equally to this work

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

Unilateral Adrenalectomy for Pediatric Cyclical Cushing Syndrome With Novel PRKAR1A Variant Associated Carney Complex

Abstract

Primary pigmented nodular adrenocortical disease is a rare cause of Cushing syndrome accounting for less than 1% of cases. We present a 9-year-old boy who presented at age 4 with cyclical Cushing syndrome and was eventually diagnosed with a novel, previously unreported, unpublished variant in PRKAR1A associated with Carney complex. He was treated with unilateral left adrenalectomy. At 1-year follow-up, he continues to be in remission of his symptoms of Cushing syndrome.

Introduction

Cushing syndrome is characterized by prolonged exposure to excess glucocorticoids and is broadly classified as either ACTH-dependent or ACTH-independent [12]. Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of ACTH-independent Cushing syndrome, characterized by bilateral adrenal hyperplasia with autonomous, hyperfunctioning nodules [12]. Approximately 90% of PPNAD cases occur in the context of Carney complex, with isolated cases being exceedingly uncommon [12].

PPNAD was first described in 1984 by Carney et al, who coined the term in a case series of 4 patients and a review of 24 previously reported cases [1]. In that series, patients presented with ACTH-independent Cushing syndrome and no radiographic evidence of adrenal tumors. All underwent bilateral adrenalectomy, with histopathology revealing bilateral pigmented nodules in otherwise small or normal-sized adrenal glands [1]. Histologically, the classic features of PPNAD include multiple small black or brown cortical nodules surrounded by an atrophic adrenal cortex—reflecting chronic ACTH suppression [1].

Clinically, PPNAD most often presents with cyclical Cushing syndrome, characterized by alternating periods of hypercortisolism and normocortisolemia [2]. This intermittent pattern poses a substantial diagnostic challenge, as biochemical confirmation requires detection of cortisol excess during active phases of the cycle.

Carney complex is a multiple neoplasia syndrome involving endocrine, cardiac, cutaneous, and neural tumors. First described by Carney et al in 1985, it is typically inherited in an autosomal dominant fashion. Approximately 70% of cases occur in familial settings, while the remaining 30% arise from de novo pathogenic variants [34]. Over half of affected individuals harbor pathogenic variants in the PRKAR1A tumor suppressor gene on chromosome 17q24.2, while approximately 20% of cases are linked to alternate loci such as 2p16 [24].

Diagnostic criteria for Carney complex include either 2 clinical manifestations or 1 clinical manifestation in combination with a pathogenic PRKAR1A variant or an affected first-degree relative [2]. The most common endocrine manifestation is PPNAD, reported in approximately 25% of patients with Carney complex, though this likely underestimates the true prevalence, as autopsy studies reveal histologic evidence of PPNAD in nearly all affected individuals [2].

The Endocrine Society clinical practice guidelines recommend bilateral adrenalectomy as the definitive treatment for PPNAD, effectively curing hypercortisolism but necessitating lifelong glucocorticoid and mineralocorticoid replacement therapy due to resultant adrenal insufficiency [5]. Unilateral adrenalectomy has emerged as an alternative approach, particularly in pediatric patients, with the potential to preserve endogenous adrenal function.

Herein, we present the case of a 9-year-old boy with Carney complex and cyclical Cushing syndrome due to PPNAD, successfully managed with unilateral adrenalectomy.

Case Presentation

A 4-year-old boy presented with a week-long history of facial swelling, hyperphagia, weight gain, and scrotal swelling. At presentation, his weight was 22 kg (99th percentile) and body mass index (BMI) was 18 kg/m² (96th percentile). Initial workup revealed normal 24-hour urinary free cortisol <0.0913 µg/day (SI: 274 nmol/day) with low urinary creatinine 215 mg/day (SI: 1.9 mmol/day) (normal reference range 973-2195 mg/day; SI: 8.6-19.4 mmol/day) suggesting an incomplete sample. A repeat collection produced similar results. A 1 mg dexamethasone suppression test demonstrated nonsuppressed cortisol (27.9 µg/dL; SI: 772 nmol/L), suggestive of Cushing syndrome.

Over 5 years, the patient experienced 2 to 3 episodes per year of rapid weight gain (20-50 lbs), facial flushing, abdominal distention, and mood changes. Despite persistent obesity (>97th percentile), linear growth remained normal.

Diagnostic Assessment

At age 7, midnight salivary cortisol was markedly elevated at 3.7 µg/dL (SI: 103 nmol/L) (normal reference range < 0.4 µg/dL; SI: < 11.3 nmol/L), raising suspicion for cyclical Cushing syndrome. Magnetic resonance imaging of the abdomen was negative for adrenal lesions. At age 8, during an active episode, 2 elevated salivary cortisol samples, 2.0 µg/dL (SI: 55.1 nmol/L) and 2.2 µg/dL (SI: 61.9 nmol/L) (normal reference range < 0.4 µg/dL; SI: < 11.3 nmol/L), were obtained. A high-dose dexamethasone suppression test yielded a low baseline cortisol 3.2 µg/dL (SI: 89 nmol/L) and nonsuppressed cortisol post-dexamethasone 3.0 µg/dL (SI: 83 nmol/L). Baseline ACTH was 7.7 pg/mL (SI: 1.7 pmol/L), suppressed to <3.2 pg/mL (SI: < 0.7 pmol/L) post-dexamethasone—consistent with ACTH-independent cortisol excess.

At age 9, the patient underwent the gold standard diagnostic testing for cyclical Cushing, the Liddle test. The test involves 6 days of urine collection: days 1 to 2 establish baseline urinary cortisol levels, days 3 to 4 assess response to low-dose dexamethasone, and days 5 to 6 evaluate response to high-dose dexamethasone. The patient’s cortisol increased paradoxically from 118.5 µg/day (SI: 327 nmol/day) to 402.0 µg/day (SI: 1109 nmol/day) over 6 days, consistent with PPNAD physiology. Genetic testing was performed with the following report: “A heterozygous variant, NM_002734.4(PRKAR1A):c.550-2_553delinsG, p.(Val184_Tyr185delinsAsp), was detected in exon 7 of this gene. This variant does not appear to have been reported in population (gnomAD, ESP, dbSNP) and clinical databases (ClinVar), or in the literature. The impact of this variant on RNA splicing as assessed by multiple algorithms (Alamut Suite) is: abolishment of canonical acceptor splice site. Based on the current evidence, this variant was classified as likely pathogenic, American College for Medical Genetics category 2”. Family testing revealed this to be a de novo pathogenic variant.

Further workup included echocardiogram and thyroid ultrasound, both of which were normal. During workup for scrotal swelling at initial presentation, the patient was found to have bilateral testicular masses with negative testicular cancer tumor markers: α-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase. The family declined invasive biopsy of these lesions. He was followed by pediatric urology with yearly serial ultrasound, and these were felt to be benign testicular tumors, presumed noncalcifying Sertoli cell tumors, associated with Carney complex (Fig. 1).

 

Ultrasound of bilateral testicular lesions. A) Left testicle. B) Right testicle.

Figure 1.

Ultrasound of bilateral testicular lesions. A) Left testicle. B) Right testicle.

Based on the presence of 2 major diagnostic criteria in combination with the molecular diagnosis of a likely pathogenic variant of PRKAR1A, the diagnosis of Carney complex was established.

Treatment

The patient was referred for surgical evaluation for consideration of adrenalectomy. A comprehensive discussion was conducted regarding the potential benefits and risks of unilateral vs bilateral adrenalectomy. The family was counseled that unilateral adrenalectomy might not fully resolve the hypercortisolemia and that a subsequent contralateral adrenalectomy could be necessary. In contrast, bilateral adrenalectomy would definitively address cortisol excess but result in permanent adrenal insufficiency requiring lifelong glucocorticoid and mineralocorticoid replacement. After multidisciplinary consultation with endocrinology and surgery, the decision was made to proceed with unilateral adrenalectomy.

Preoperative IV contrast-enhanced computed tomography (CT), reviewed by a physician experienced in PPNAD, demonstrated greater nodularity in the left adrenal gland compared to the right. Therefore, a laparoscopic left adrenalectomy was performed electively without intraoperative complications. The patient was discharged on postoperative day 1. At the time of surgery (age 9), his weight was 70 kg (100th percentile), and BMI was 31.6 kg/m² (99th percentile). The resected left adrenal gland was submitted for histopathologic evaluation. Gross examination revealed no overt nodularity (Fig. 2); however, microscopic analysis identified multiple pigmented cortical nodules consistent with PPNAD (Fig. 3).

 

Left adrenal gland gross morphology. No macroscopic nodularity appreciable.

Figure 2.

Left adrenal gland gross morphology. No macroscopic nodularity appreciable.

 

Hematoxylin and Eosin staining on microscopy of left adrenal gland demonstrating hyperpigmented nodule.

Figure 3.

Hematoxylin and Eosin staining on microscopy of left adrenal gland demonstrating hyperpigmented nodule.

Outcome and Follow-up

The patient was followed closely in the postoperative period and was last evaluated 11 months after adrenalectomy. He remained clinically well, with complete resolution of Cushingoid features and no evidence of recurrence. Since surgery, he had experienced significant weight loss of 11.4 kg, with a current weight of 58.6 kg and a BMI of 25 kg/m² (97th percentile).

In summary, this case describes a 9-year-old boy with ACTH-independent, cyclical Cushing syndrome secondary to PPNAD, associated with a de novo likely pathogenic variant in the PRKAR1A gene, consistent with Carney complex. Histopathologic analysis of the resected adrenal gland confirmed the diagnosis of PPNAD. At nearly 1 year post-unilateral adrenalectomy, the patient remains asymptomatic with no biochemical or clinical signs of disease recurrence.

Discussion

Diagnosis of cyclical Cushing is challenging due to the cyclical nature of the disease and the challenges with current available testing modalities. Late-night salivary cortisol testing was a more reliable screening tool in this case as the 24-hour urinary cortisol were affected by inaccurate collection. The cyclical nature of the disease, coupled with the necessity for appropriately timed testing, contributed to a prolonged interval before definitive diagnosis and treatment. Additionally, initial imaging was interpreted as normal, and it was only upon review by a clinician with expertise in PPNAD that subtle adrenal nodularity was identified on CT. Ultimately, the Liddle test and genetic testing were the highest yield for confirmation of disease. This test measures the suppressibility of endogenous cortisol following exogenous dexamethasone administration. In patients with PPNAD, a paradoxical increase in cortisol excretion may occur, attributed to glucocorticoid receptor–mediated activation of protein kinase A catalytic subunits [6]. The likely pathogenic variant found in this case is a novel, previously unreported, variant in the PRKAR1A gene. This rare variant impact both the canonical acceptor splice site in intron 6 as well as results in an in-frame protein change in exon 7 (Val184_Tyr185delinsAsp).

The treatment of PPNAD in the context of Carney complex is typically with bilateral adrenalectomy, as per Endocrine Society guidelines [5]. The drawback of bilateral adrenalectomy is the resultant adrenal insufficiency resulting in lifelong adrenal replacement. Unilateral adrenalectomy is an attractive option for the treatment of PPNAD given the ability to avoid adrenal insufficiency brought upon by bilateral adrenalectomy. Case reports and case series in adult patients have demonstrated variable success in unilateral treatment. In a case series of 17 patients with classic cyclical Cushing, 3 patients had recurrence of Cushing syndrome after unilateral adrenalectomy and were cured with contralateral adrenalectomy [7]. One patient had subtotal (<90%) left adrenalectomy and did not have recurrence with 66 years of follow-up [7].

A case series by Xu et al 2013 described 12 out of 13 patients with PPNAD successfully cured with unilateral adrenalectomy at median 47 months follow-up [8]. The side of adrenalectomy was selected based on CT/magnetic resonance imaging in 3 patients and adrenal iodine131-norcholesterol scintigraphy in the remaining. At our center, the iodine131-norcholesterol scintigraphy was not available so CT was the chosen imaging modality.

Ultimately, the efficacy and morbidity of unilateral adrenalectomy remains unclear. Furthermore, due to the rarity of PPNAD, the criteria for selection of patients who are candidates for unliteral adrenalectomy is challenging to establish. This case reports adds to the existing literature the clinical characteristics of one patient treated successfully by unilateral adrenalectomy.

Learning Points

  • Diagnosis of cyclical Cushing can be very challenging. Late-night salivary cortisol is more reliable than 24-hour urinary cortisol.
  • The paradoxical rise in cortisol in the Liddle test is confirmatory for cyclical Cushing, hence the testing should be considered early in affected patients.
  • Genetic testing assessing for Carney complex, PRAKA1A pathogenic variant, should be considered early in a patient with concern for cyclical Cushing and another system involved like testicular lesions.
  • Although bilateral adrenalectomy is the recommendation for PPNAD; in selected patients, unilateral adrenalectomy might provide several years of remission.

Acknowledgements

Thank you to Dr. Hong Wang, MD, PhD, DABMGG, FACMG, FCCMG, for her support on this project and in all things. Thank you to Dr. Andre Lacroix MD, FCAHS, for reviewing the preoperative CT adrenals with the team.

Contributors

All authors made individual contributions to authorship. F.B. was involved in the diagnosis and management of the patient. N.S. was responsible for the patient’s surgery. C.J.Z. was involved in the patient’s surgery and postoperative care. R.S., M.S., and P.W. were all medical professionals involved in his management and care. All authors contributed, reviewed, and approved the final draft.

Funding

No public or commercial funding.

Disclosures

None declared.

Informed Patient Consent for Publication

Signed informed consent obtained directly from the patient’s relatives or guardians

Data Availability Statement

Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.

Author notes

Natashia Seemann and Funmbi Babalola co-senior author.

© The Author(s) 2025. Published by Oxford University Press on behalf of the Endocrine Society.
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A Case Series of Bilateral Inferior Petrosal Sinus Sampling Using Desmopressin for Evaluation of ACTH-Dependent Cushing’s Syndrome in Pediatric Patients

Abstract

Background

Pediatric Cushing Syndrome (CS) is rare and difficult to diagnose, especially when distinguishing ACTH-dependent subtypes. Bilateral inferior petrosal sinus sampling (BIPSS) is an essential but technically challenging procedure for this purpose. Because corticotropin-releasing hormone (CRH), the standard stimulant, has limitations, desmopressin is being explored as an alternative. This study assesses desmopressin-stimulated BIPSS for its diagnostic accuracy and tumor localization in pediatric CS within an Iranian cohort, addressing a gap in pediatric-specific diagnostic strategies and offering insights into the applicability of desmopressin in this context.

Methods

Four pediatric patients with inconclusive pituitary imaging and suspected Cushing’s disease (CD) underwent BIPSS with desmopressin at Taleghani Hospital, Tehran, Iran, between August 2015 and March 2019. Sensitivity of BIPSS for CD diagnosis was assessed, and tumor localization accuracy was evaluated during surgery.

Results

Bilateral IPSS demonstrated a sensitivity of 100% for diagnosing CD in pediatric patients. However, accuracy for tumor lateralization was moderate, with only 50% concordance between BIPSS lateralization and surgical findings. Specifically, two out of four patients had correct lateralization confirmed during surgery, while one patient with left lateralization was consistent with hypophysectomy findings. These discrepancies highlight challenges such as anatomical and drainage variations that can lead to mislocalization.

Conclusion

Desmopressin enhances the sensitivity of BIPSS for diagnosing pediatric CD, presenting as a viable alternative to CRH stimulation. Despite high sensitivity, caution is advised when interpreting BIPSS results for tumor localization. Further research is needed to optimize diagnostic strategies for pediatric CS management.

From https://link.springer.com/article/10.1007/s40200-025-01634-4

Cushing Syndrome in Paediatric Population

Introduction

Cushing’s syndrome (CS) may be defined as a clinical condition characterised by signs and symptoms resulting from excessive and prolonged exposure to glucocorticoids. CS can be differentiated into an exogenous form due to high-dose and prolonged glucocorticoid treatments and an endogenous form caused by excessive cortisol secretion.
In paediatric population, the exogenous CS represents the most frequent type of CS due to the widespread therapeutic use of glucocorticoids (given by systemic or local routes) for pulmonary, renal, haematological, or rheumatological diseases, more rarely due to an unappropriated administration of glucocorticoids by parents (medical child abuse or “Munchausen syndrome by proxy”). Endogenous CS is very rare, with an overall incidence of 1.2-5 per million per year [14], of which 10% of cases occurs in paediatric age [56].
According to the origin of the hypercortisolism, endogenous CS can be also differentiated into an ACTH-dependent form resulting from ACTH-secreting pituitary neuroendocrine tumours (Cushing’s disease, CD) or ACTH-and or corticotropin releasing hormone (CRH) secreting neuroendocrine tumours outside the hypothalamic-pituitary area (ectopic Cushing syndrome, ECS), and an ACTH-independent form of adrenal origin (adrenal Cushing’s syndrome, ACS) (adenoma, carcinoma or bilateral adrenal hyperplasia). Finally, there are some clinical conditions, such as psychiatric disorders, severe obesity, poorly controlled diabetes mellitus, anorexia or intense physical exercise, that are associated with non-physiological hypercortisolism (non-neoplastic hypercortisolism, NNH, formerly known as Pseudo-Cushing’s syndrome) caused by chronic stimuli on hypothalamic-pituitary-adrenal axis.
NNH, particularly when characterized by moderate hypercortisolism, have often several clinical characteristics similar to CS and the first-line tests for screening endogenous hypercortisolism may provide misleading results, making the differential diagnosis very challenging. Besides the clinical history, the duration of symptoms and the first-line tests, second-line dynamic tests can be performed to better discriminate NNH from CS [79]. A recent systematic review and metanalysis provide an overview about the usefulness of the second-line tests to differentiate NNH from CS [10].
Similar to adult population, CD represents the most common form of CS in paediatric age (about 75–80%), while about 15–20% of cases are ascribed to ACS and less than 2% to ectopic origin, although there is a different distribution by age [1112]. In fact, CD occurs often in adolescent and pre-adolescent age, while endogenous CS in children younger than 8 years is mainly caused by adrenal tumours [1314]. CD in younger children with a relevant family history may be caused by rare genetic causes, since the pituitary adenomas should be the first presentation of MEN1, AIP gene mutations or more rare genetic mutations (as CDKNIB or DICER1 gene) [15].
According to some large epidemiological series studies, adrenocortical tumours present a peak incidence during the first decade, with a median age at diagnosis of 3–4 years [16] and are relatively more frequent in paediatric age than in adulthood. Paediatric adrenocortical tumours are almost always functional, presenting with virilization due to excess androgen secretion alone or in combination with hypercortisolism in about 80% of cases [16]. Adrenal tumours can be isolated or in the context of predisposing genetic syndromes as Li-Fraumeni or Beckwith-Wiedemann syndrome. Primary pigmented nodular adrenocortical disease (PPNAD) is a rare congenital disorder, occurring in late adolescence, mostly (about 95% of cases) associated with the multiple endocrine neoplasia (MEN) syndrome known as Carney complex [13]. Macronodular adrenal hyperplasia is rarely reported in the paediatric population, while another form of bilateral adrenocortical hyperplasia includes the adrenal lesions in McCune-Albright syndrome, which represents the first cause of CS in infants [5131718]. ECS is extremely rare in childhood, and is associated to neuroendocrine tumours, mostly bronchial, thymic, renal and duodenal or pancreatic carcinoids [5131920].

Methods

An extensive MEDLINE search was performed in 2023 for the research question by two authors (LC, GP) independently, and discrepancies were resolved by discussion. A literature search was performed from 1970 to 2023. The following search words were included: “Cushing’s Syndrome, Cushing’s disease, children, childhood, diagnosis, endogenous hypercortisolism”. Search terms were linked to the Medical Subject Headings (MeSH) when possible. Keywords and free words were used simultaneously. Additional articles were identified with manual searches and included thorough review of other meta-analyses, review articles, and relevant references.

Clinical presentation of CS in children

The diagnosis of CS is often difficult due to the insidious onset of hypercortisolism, in absence of relevant early signs of the disease, as well as the rarity of the disease in childhood. For these reasons, the time to diagnosis has been reported as a mean of 33 months (95% CI 29–38) and not dissimilar to adult population [21].
In childhood, the most common and earliest sign of CS is weight gain, which becomes pathognomonic when combined with concomitant growth failure. Generally, the discrepancy between height SDS and BMI SDS is suggestive of CS, although short stature (defined as height inferior to -2 SDS) is not always reported [2223]. On the other hand, decreased height velocity or growth arrest always occurs in childhood CS, due to the inhibitory action of glucocorticoids on growth plate cartilage, except for subjects presenting a concomitant hyperandrogenism in which growth may be normal or even increased. Some authors have suggested to consider children with height inferior to 0 SDS and BMI over + 1.5 SDS for CS diagnosis, allowing to differentiate from subjects with simple obesity, which often present tall stature [624]. Ultimately, growth arrest could be considered the main red flag sign for paediatricians in suspected CS.
Other common signs reported in childhood and adolescence include swelling of the face (as plethora or moon face), headaches, striae rubrae, acanthosis nigricans, dorsal cervical or supraclavicular fat pads and osteopenia. The main clinical findings in paediatric CS are showed in Table 1.
Table 1

Clinical characteristics of paediatric cushing syndrome (CS)
Magiakou 1994 [23]
Devoe 1997 [25]
Storr 2011 [26]
Shah 2011 [22]
Lonser 2013 [27]
Guemes 2016 [28]
Number of patients (F/M)
59 (37/22)
42 (25/17)
41 (15/26)
48 (19/29)
200 (106/94)
30 (14/16)
Period of observation
1982–1992
1974–1993
1983–2010
1988–2008
1982–2010
1983–2013
Subtype of CS
Pituitary (50)
Adrenal (6)
Ectopic (3)
Pituitary
Pituitary
Pituitary
Pituitary
Pituitary (16), Adrenal (11), Ectopic (2), Unknown (1)
Mean age at onset (y) or duration of symptoms (m)
11±4 y
9±6 y
10±3 y
NA
NA
23.6 ± 14.2 m
10.6 ± 3.6 y
12 m (6–18)
Mean age at diagnosis (range)
14±4
10±5
11±4
13.1 y (6.5–18)a
12.3 ± 3.5 y (5.7–17.8)
14.85 ± 2.5 y (9–19)
13.7 ± 3.7 y
8.9 (0.2–15.5)a
SDS Height at diagnosis (range)
-1.3±1.5
-1.0±1.3
-0.1±0.9
-1.8 (-3.5 to + 0.3)
-1.8 ± 1.3 (-1.2 to -4.2)
NAb
NA
-0.3 (-3.2 to + 3.0)c
Signs and symptoms (%)
Weight gain
90
92
98
98
93
76.6
Growth retardation
83
84
100
83
63
36.6
Facial changes
46
100
98
63
Fatigue
44
67
61
48
40
Pubertal lack or delay
60
10
Hirsutism
78
46
59
56
56.6
Acne
47
46
44
47
50
Amenorrhea (primary or secondary
78
49
Virilization
38
76
26.6
Gynecomastia
16
Osteopenia
74
Dorsal cervical fat pad
28
69
Striae rubrae
61
36
49
58
55
26.6
Acanthosis nigricans
12
75
32
Headache
26
51
38
Hypertension
47
63
49
71
36
50
Psychiatric disorders
19
44
59
46
31
43.3
Sleep disturbances
20
Muscle weakness
48
Easy bruising
28
17
25
20
Glucose intolerance or diabetes
25
7
Abbreviation. F: female; M: male; SDS: Standard deviation score; y: years; m: months; NA: not available. a median age; b 56% of subjects presented short stature; c median SDS height
The excess of adrenal androgens is responsible for the appearance of acne, hirsutism and early secondary sexual development (i.e., precocious pubic hair growth) in prepubertal children, while the consequent inhibition of gonadotropins secretion may lead of a lack or delay of pubertal development. However, in adolescence, adrenal hyperandrogenism and hypogonadism may result in menstrual changes (as oligo- or amenorrhea), virilization or gynecomastia. Adrenocortical tumours are often characterised by severe concomitant hyperandrogenism, presenting with hirsutism, acne or virilization.
Additional clinical features reported in paediatric population include depression, behaviour disorders (as anxiety, mood swings, emotional lability) and asthenia, while other typical signs of CS in adulthood as myopathy-related fatigue, easy bruising or hypertension are less common during childhood and adolescence [622232529].
Considering the extreme rarity of CS and the increasing incidence of obesity in childhood, an extensive screening of the entire paediatric population with obesity is not recommended. It is however important to raise awareness amongst paediatricians to recognize few key features of CS, like facial changes, weight gain with simultaneous growth failure, prepubertal virilisation as menstrual changes or hypogonadism signs in adolescence.
Since the clinical features of NNH are often indistinguishable from neoplastic CS, a good history and examination (as individual growth charts), in addition to specific diagnostic tests, are needed to better rule out any physical or psychological causes of NNH [9].
In identify the different origin of CS based on symptoms, it should be considered that ECS is more commonly associated with catabolic signs (muscle weakness, osteoporotic fractures), little or no weight gain, hypertension and hypokalaemia due to the mineralocorticoid effect of cortisol excess. In fact, very high cortisol levels can cause the saturation of the type-2 11β-Hydroxysteroid Dehydrogenase (11βHSD-2) enzyme, expressed in renal cortex and responsive to convert cortisol into inactive cortisone, leading to spillover of cortisol to the mineralocorticoid receptor. Because of this biochemical mechanism, severe hypercortisolism may be considered as a functional mineralocorticoid excess state causing hypokalaemia, increased renal tubular sodium reabsorption, consequent intravascular volume expansion and hypertension [3032]. However, since the clinical spectrum of presentation of ECS may overlap with CD, the differential diagnosis is challenging and requires the combination of dynamic biochemical testing and multimodal imaging, each with its own pitfalls [172033].

Diagnostic workup for CS

Once a possible intake of exogenous corticosteroids has been ruled out through a careful medical history, the first step in the diagnostic workup is the identification of endogenous hypercortisolism.

Screening for endogenous hypercortisolism

Endogenous hypercortisolism in the paediatric population is essentially demonstrated with the following tests: 24-h urinary free cortisol (UFC), late-night salivary or serum cortisol and dexamethasone-suppression testing. Because none of these tests has 100% of diagnostic accuracy, as for adulthood, at least two tests are usually needed to confirm endogenous CS [7]. Table 2 shows the statistical features of the three diagnostic tests reported in the paediatric population.
Table 2

Diagnostic tests performed for endogenous hypercortisolism screening in the paediatric population
Author
Population Age (mean)
Subject characteristics (N)
Test
Cut-off
Sensibility
Specificity
Bickler 1994 [54]
15.7 y (pituitary)
8.1 y (adrenal)
Pituitary (10)
Adrenal (2)
UFC
> 60 mg/m2
100% (8/8)
LDDST
< 50% of basal serum cortisol
91% (10/11)
Devoe 1997 [25]
13.1 y (6.5–18)a
Pituitary (42)
UFC
> 70 µg/m2
86% (25/29)
Martinelli 1999 [49]
10.2 ± 5 y
Pituitary (5), Adrenal (6), Obese controls (21)
Late-night salivary cortisol
> 7.5 nmol/l
100% (11/11)
95.2% (20/21)
Gafni 2000 [39]
5–17 y
CS patients (14), Healthy controls (53)
UFC
> 72 µg/m2
93% (13/14)
100% (53/53)
Late-night salivary cortisol
> 7.5 nmol/l
93% (13/14)
100% (53/53)
Davies 2005 [47]
12.2 y
Pituitary (14)
Late-night serum cortisol
> 50 nmol/l [1.8 µg/dl]
100% (14/14)
Batista 2007 [38]
3–18 y
Pituitary (80), Adrenal (25), Controls (20)
UFC
> 70 µg/m2
88% (92/105) [PPV 98%]
90% (18/20) [NPV 58%]
Late-night serum cortisol
> 4.4 µg/dl
99% (104/105)
[PPV 100%]
100% (20/20) [NPV 95%]
Shah 2011 [22]
14.85 ± 2.5 y
Pituitary (48)
Late-night serum cortisol
> 3.2 µg/dl
100% (38/38)
LDDST (30 µg/kg/day [max 2 mg/day] divided every 6 h for 48 h
≥ 1.8 µg/dl
100% (48/48)
≥ 5 µg/dl
94% (45/48)
Storr 2011 [26]
12.3 ± 3.5 y
Pituitary (41)
LDDST (30 µg/kg/day [max 2 mg/day] divided every 6 h for 48 h)
< 50 nmol/l [1.8 µg/dl]
92% (35/38)
Lonser 2013 [27]
13.7 ± 3.7 y
Pituitary (200)
UFC
Age-appropriate reference
99% (177/179)
> 70 µg/m2
88% (155/177)
Late-night serum cortisol
> 7.5 µg/dl
97% (188/193)
Shapiro 2016 [40]
11.7 y (pituitary), 12.9 y (adrenal), 11.5 y (controls)
Pituitary (39), Adrenal (8), Control (19)
UFC (different assays)
Corrected for BSA
89% (34/38)
100%
Wędrychowicz 2019 [55]
11.7 y
Pituitary (4)
UFC
> 55 µg/24 h
100% (4/4)
Late-night serum cortisol
> 4.4 µg/dl
100% (4/4)
Overnight DST (1 mg at 11.00 p.m.)
< 1.8 µg/dl
75% (3/4)
Guemes 2016 [28]
8.9 y (0.2–15.5)a
Pituitary (16), Adrenal (11), Ectopic (2), Unknown (1)
UFC
> 275 nmol [100 µg]/24 h
94% (17/18)
Late-night serum cortisol
> 138 nmol/l [5 µg/dl]
100% (27/27)
LDDST (20 µg/kg/day [max 2 mg/day] divided every 6 h for 48 h)
< 50 nmol/l [1.8 µg/dl]
100% (20/20)
Abbreviation. N: number; y: years; UFC: Urinary free cortisol; DST: dexamethasone suppression test; LDDST: low-dose DST; PPV: Positive Predictive Value; NPV: Negative Predictive Value; BSA: body surface area. a median age
Recently, some authors have reported the value of hair cortisol measurements as a good marker of hypercortisolism also in paediatric population [34], although further studies are needed to validate this test in the diagnostic workup for CS.

24-h Urinary free cortisol (UFC)

24-h UFC is a long-time used screening test for CS, widely performed in childhood for its non-invasive characteristics and the possibility to collect the 24-h samples at home, although this collection may be difficult for younger subjects. Differently from adults, in paediatric population UFC should be corrected for body surface area, conventionally used to make the normal range homogeneous despite the different cortisol secretion during childhood and puberty [3537]. The cut-off of 70 µg/m2/day is associated with an acceptable sensitivity and specificity (over 88% and 90% respectively) [273839], even if the normal ranges varied among different paediatric studies, due to assay-specific reference range [252840]. In order to reduce intra-patient variability and to provide a better diagnostic accuracy, it is now recognised that at least two UFC measurements should be performed in subjects suspected of CS [27384041].
Mild forms of hypercortisolism may have a false-negative UFC assay, because free cortisol appears in the urine only when serum cortisol exceeds the plasma protein binding capacity. On the other hand, false-positive elevation of UFC measurements should be caused by NNH, as physical or emotional stress, severe obesity or depression. In fact, obese children and adolescents may present slightly elevated UFC, particularly when the obesity is associated with metabolic syndrome [4243].
Considering the extremely low prevalence of CS in the paediatric population, the positive predictive value of UFC measurements is considerably low. For this reason, UFC alone is not recognised as an ideal screening tool, while its use combined with another screening tests is desirable to better detect subjects with endogenous hypercortisolism.
In the last decades, liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays had demonstrated superior sensitivity and specificity compared to traditional immunoassays [4446], reducing a considerable analytical bias thanks to its ability to differentiate various glucocorticoid metabolites.

Late night cortisol

Abnormal circadian rhythm of cortisol secretion is a hallmark of CS. The lack of the physiological evening nadir in cortisol secretion is detectable with late-night serum or salivary cortisol tests. As for UFC, at least two late-night cortisol measurements are desirable to improve the diagnostic accuracy, particularly in patients with mild CS.
For serum cortisol measurement, an indwelling intravenous cannula should be placed before sleeping and the blood sample should be taken without waking the child. The assessment of midnight serum cortisol gives the highest sensitivity and specificity for the diagnosis of CS in childhood (99 and 100% respectively using the cut-off of 4.4 µg/dl) [38], despite different normal ranges (between 1.8 and 5 µg/dl) have been considered for paediatric subjects [222847].
However, the late-night serum sample requires hospitalization and its use as a screening test for CS is limited.
On the other hand, late-night salivary cortisol measurement represents an easily executable, stress-free test also in outpatient setting. Conventionally, the salivary samples are collected at 11–12 pm, even if some authors suggest to performed it at usual bedtime in order to achieve unstressed levels, resulting from the request to the patient to stay awake beyond the usual bedtime [48]. This precaution, suggested for adult subjects, should be considered also for paediatric population to reduce a potential false-positive rate of the test.
Although the available data in paediatric population are limited, the sensitivity and specificity of late-night salivary cortisol assessment appear to be close to late-night serum cortisol (93–100% and 95–100% respectively) [3949].
For all these reasons, late-night salivary cortisol seems to be the best screening test for endogenous hypercortisolism in childhood.
Although the traditional immunoassay methods already have a very high sensitivity, LC-MS/MS assays had demonstrated an improvement of diagnostic specificity and appear to be the most accurate analytical tools also for modern salivary or serum steroid measurements [5052]. In fact, the use of LC-MS/MS assay allows the dosage of different cortisol metabolites (as cortisone) in order to better identify the endogenous cortisol production and consequently to reduce false-positive results [851].

Low-dose dexamethasone suppression tests (DST)

In healthy individuals, a supraphysiological exogenous dexamethasone dose inhibits ACTH and consequently cortisol secretion. Therefore, a decrease of serum cortisol concentration below the value of 1.8 µg/dl after 1 or 2 mg dexamethasone dose is considered to be a normal response. The low-dose DST should be performed through two different forms: the 1 mg “overnight” (or Nugent) and the two-day 2 mg (or low-dose Liddle) test.
The “overnight” DST is performed with the administration of 1 mg (or 25 µg/kg in children with body weight < 40 kg) of dexamethasone at 11 PM to 12 AM (midnight), measuring serum cortisol at 8 AM the next morning. In order to ensure a proper DST in adult population, Ceccato et al. propose to measure also dexamethasone after 1 mg-DST with LC-MS/MS assay [53]. At present, no similar data are available among paediatric population, although dexamethasone measurement should be suggested also in children and adolescents to reduce false-positive results due to inadequate bioavailability or incorrect administration of dexamethasone.
The “low-dose Liddle” DST (LDDST) consists of the administration of 2 mg/day of dexamethasone (or 20–30 µg/kg/day in children < 30 kg), divided in 0.5 mg doses every six hours for 48 h, and measurement of serum cortisol within six hours after the last dose.
For both DST, the lack of the physiological serum cortisol suppression (< 1.8 µg/dL) is suspicious for CS. LDDST has demonstrated a good sensitivity (over 90%) for CS in paediatric patients [2628], whereas less data regarding the overnight DST sensitivity and specificity are available in childhood [5455].
For its ease analysis in an out-patient setting, LDDST is therefore a useful screening test for paediatric patients suspected of CS.
Recently, some authors have investigated the utility of salivary cortisone measurement after DST, that is characterized by a more linear relationship with serum cortisol than salivary cortisol [56]. Moreover, a prospective use of salivary cortisol/cortisone after DST in childhood should be encouraged for its non-invasive and stress-free peculiarity, avoiding venipuncture.

Etiological diagnosis of endogenous CS

Basal electrolytes and ACTH

Levels of serum electrolytes are usually normal, but potassium may be decreased, especially in children with ECS [57]. In children with CD, morning plasma ACTH is commonly detectable (> 5 pg/ml) while those with ACS showed suppressed ACTH [29]. Batista et al. showed that a cut-off of morning ACTH of 29 pg/ml had a sensitivity of 70% and specificity of 100% to differentiate ACTH-dependent from ACTH-independent CS [38]. ACTH concentrations are usually very high in patients with ECS but may be normal in patients with pituitary adenomas [172957]. CD should be suspected in patients with biologically moderate signs, without hypokalaemia or marked plasma ACTH elevation and with progressive onset [172033].

CRH stimulation test

The CRH test has been suggested as the best non-invasive tool for diagnosing CD. Sensitivity and specificity are reported to be around 80 and 92% (according to study in adults) [175860]. This test consists in the intravenous injection of 1 µg/kg CRH (maximum dose 100 µg) [29]. The criterion for diagnosis of CD is a mean increase of 20% above baseline for cortisol value at 15 and 30 min and an increase in the mean ACTH concentration of at least 35% over basal value at 15 and 30 min after CRH administration [1729]. Some authors reported the use of ovine CRH (the only available form in the United States, until the mid-2020) in paediatric population [3861] as alternative to human CRH. Although it has been described as the ovine CRH can induce a stronger, more prolonged increase in ACTH and, particularly, cortisol compared with human CRH in adult subjects [62], no data are available comparing ovine and human CRH in paediatric population.
Despite children with CD seem to have a more evident cortisol response than adults, making this test more useful in the paediatric age than in adults [17262963], the recent synthetic human CRH shortage [64] will make CRH test less feasible in favour of other dynamic tests as Desmopressin test [65].

Desmopressin test

Desmopressin is a preferential vasopressin receptor V2 and V3 agonist. Because of the overexpression of the V3 in human ACTH-secreting adenomas, the administration of desmopressin causes a significant rise in ACTH and cortisol levels in most patients with CD [1758]. This makes desmopressin administration a suitable test enabling the distinction between neoplastic from NNH [91026]. Like CRH test, Desmopressin test results effective, well-tolerated, less expensive, and relatively non-invasive. While the sensitivity is comparable to CRH test, the specificity seems to be lower [17586066]. Like the other tests, it is probabilistic: the more significant the elevation of ACTH and cortisol, the more probable the diagnosis of corticotropic adenoma [1758]. Different cut-off criteria were used to define a positive response. Malerbi et al. showed that the administration of Desmopressin 5–10 µg intravenous determines a cortisol increase above baseline ranging from 61 to 379% in patients with pituitary disease [67]. Sakai et al. using a high percent ACTH rise threshold of 120% reported a positive ACTH response in all 10 patients with CD, whereas all 3 patients with ECS were unresponsive to desmopressin [68]. Tsagarakis et al. showed that desmopressin test (10 µg intravenous) can produce a significant overlap of responses between CD and patients with ECS and therefore it is of limited value in the differential diagnosis of ACTH-dependent CS. This is probably due to the expression of the V2 receptors in tumours with ECS [69]. Desmopressin (10 µg intravenous) in combination with CRH may provide an improvement over the standard CRH test in the differential diagnosis of ACTH-dependent CS [70]. However, the benefit of a desmopressin-CRH combined test results limited [66]. It should be considered that all the above studies included adults [6769].
Desmopressin test proved to be effective in increasing the sensibility of Bilateral Petrosal Sinus Sampling (BIPSS) [71]. In a retrospective study including 16 children with CD, Chen et al. showed an increase of the sensitivity of BIPSS from 64.7% at baseline to 83.3% after desmopressin stimulation [72]. Many CD patients respond aberrantly to the desmopressin test. Loss of the desmopressin response, performed in the early post-operative period, is a good predictor for a favourable long-term outcome. Moreover, during follow-up, the return of desmopressin response is predictive of recurrence [6671].

Standard high dose dexamethasone suppression test (HDDST)

HDDST or high-dose Liddle test is the oldest described and it is used to differentiate CD from ECS. This test consists in the administration of dexamethasone at a dosage of 80–120µgr/kg/day divided into four doses every 6 h (maximum 2 mg/dose) for 48 h or a single cumulative dose of 80–120µgr/kg (maximum 8 mg) at 11 pm. Plasma cortisol is measured at 8–9 am the morning after the last administration of dexamethasone; the suppression of serum cortisol up to 50% of baseline is suspicious for CD as for adult population [1726282938].
Liu et al. showed that HDDST in combination with pituitary dynamic enhanced MRI (dMRI) had a positive predictive value (98.6%), higher than that of Bilateral Petrosal Sinus Sampling (BIPSS) for the diagnosis of CD [73].
Despite HDDST had reported a good sensibility to identify CD in childhood, this test seems to have a low specificity to exclude ECS because of the high degrees of cortisol suppression after HDDST in children with ECS [192829]. In addition, the administration of high-dose dexamethasone in CS patients with high cortisol level can cause severe side effects, including exacerbation of their hypertension and fluctuation of blood glucose. Because of the low accuracy and the risk of severe side effects, this test is less frequently used [29].

https://static-content.springer.com/image/art%3A10.1007%2Fs40618-024-02452-w/MediaObjects/40618_2024_2452_Fig1_HTML.png

Fig. 1

Diagnostic algorithm for screening and differential diagnosis of cushing syndrome in paediatric population

Imaging

Pituitary magnetic resonance imaging (MRI)

Since ACTH-secreting pituitary adenomas are very small (usually < 6 mm in diameter), it is difficult to localize these tumours. Diagnostic workup of CD includes pituitary MRI, but in many patients no tumour is identified. Conventional MRI, even with contrast enhancement, mostly failed to identify ACTH-secreting microadenomas in children with CD. Up to one-third of paediatric and adolescent patients with CD don’t have pituitary tumour detectable at brain MRI. The acquisition protocol should comprise coronal and sagittal spin-echo (SE) slices with gadolinium-enhanced T1 and T2 and millimetric 3D T1 slices [17295774]. In a retrospective study including 30 children with CD (mean age 12 ± 3 years), Batista et al. showed that pre- and post-contrast spoiled gradient-recalled acquisition in the steady state (SPGR) was superior to conventional pre- and post-contrast T1-weighted SE acquisition MRI in the identification of the microadenomas. In particular, the post-contrast SPGR-MRI identified the location of the tumour in 18 of 28 patients, whereas post-contrast SE-MRI identified the location and accurately estimated the size of the tumour in only 5 of 28 patients (p < 0.001) [74].

Bilateral petrosal sinus sampling (BIPSS)

BIPSS is another powerful diagnostic tool with high sensitivity and specificity, but its invasiveness and high cost limit its wide application, and the indication for BIPSS is still controversial [717297576]. It consists of the placement of femoral catheters that reach the inferior petrosal sinuses. Successively, blood samples are collected for measurement of ACTH from petrosal sinuses and from peripheral pathway before and after the administration of CRH. Inferior petrosal sinus (IPS) to peripheral (P) ACTH ratio and interpetrosal sinus gradient of one of the two sides to the contralateral side are calculated [7576]. In order to avoid incorrect results, it is recommended to verify hypercortisolism with serum cortisol sample immediately before performing BIPSS. Detomas et al. recently described the largest study on BIPSS.
According to the authors, the cut-offs for the ACTH IPS: P ≥ 1.9 at baseline (sensitivity 82.1%, specificity 85.7%) and ≥ 2.1 at 5 min post-CRH (sensitivity 91.3%, specificity 92.9%) allow for the best discrimination between CD and ECS [77]. In a multicentre study including 16 children aged between 4 and 16.5 years, Turan et al. showed that BIPSS is a superior diagnostic work-up than MRI to confirm the diagnosis of CD. Moreover, it showed a significantly higher sensitivity (92.8%) than MRI (53.3%) in detecting adenoma localization at pituitary level, which is crucial for surgical intervention [75]. The use of desmopressin has been reported in alternative to CRH [76]. In a review including case series of children with CS [76], the overall accuracy of BIPSS was 84.1% and became 92.3% after stimulation with desmopressin. The overall lateralizing accuracy of BIPSS was 50%. While BIPSS has a high diagnostic accuracy for the localization to the pituitary gland, it is not reliable for tumour lateralization to the right or left side of the gland. BIPSS is considered the gold standard to reliably exclude ECS and should performed in a specialized centre due to potential patient risk. However, BIPSS is not routinely available in many centres, it may have decreased specificity in children, especially when the pituitary tumour is not lateralized showing misleading results [7778]. For these reasons and for the risks related to the invasiveness of the procedure, BIPSS should be reserved only for exceptional cases in children [177576].

Radiological anatomic imaging

Subjects with ACS should perform an adrenal Computer Tomography (TC) or MRI to determine the adrenal cause. Despite abdominal TC with contrast-enhanced studies is the cornerstone of imaging of adrenal tumours in adults, MRI scan should be initially preferred in childhood to avoid radiation exposure [79]. Adrenocortical carcinomas are usually unilateral, larger than adenomas, with irregular margins, inhomogeneous contents (with areas of necrosis, haemorrhage and calcification) and avidly enhancement after contrast administration due to their high vascularity [80]. PPNAD is more difficult di identify with radiological studies, because it usually presents normal- or small-sized adrenal glands.
In subjects with suspected ECS, a thin-multislice neck-chest-abdomen-pelvic CT, alone or eventually followed by MRI, should be performed to identify neuroendocrine tumours that generally are very small and difficult to identify [11].

Functional imaging

Second-line functional imaging studies (as Positron Emission Tomography, PET, or scintigraphy) may be useful to provide an accurate etiological diagnosis of CS, particularly when the traditional radiological exams are inconclusive to differentiate CD from ECS. Because of the rarity of ECS, a univocal algorithm regarding the use of new molecular imaging techniques is not well established.
Whereas the ectopic ACTH-secreting tumours express the cell-surface receptors for somatostatin, 111In-pentetreotide (OCT) scintigraphy is often chosen as confirmatory exam [81].
The 68Gallium-DOTATATE PET/CT scan, using a modified octreotide molecule that also binds to somatostatin receptors, has shown a greater sensitivity for small tumours and may be useful for the tumoral identification in case of negative OCT scan [7]. Finally, 18FDG-PET/CT seems to be highly sensitive for the detection of aggressive pancreatic lesions [81].
In ACS cases, when adrenocortical carcinoma is suspected and traditional imaging studies (MRI or TC) are not diriment, 11C-metomidate-PET/CT scan allows a non-invasive characterization and staging of the adrenal lesion [8283].

Algorithm approach

Clinical history and the age at presentation of symptoms should guide throughout the different diagnosis of endogenous CS. A careful personal history, supported by patient growth charts, physical examination and screening tests should be able to rule out any physical or neuropsychiatric causes of NNH, even if second-line dynamic tests are sometimes needed to distinguish NNH from neoplastic CS.
Although CD is the main cause of CS in children older than 8 years, the clinical presentation of ECS may overlap with CD and the differential diagnosis of CS may be challenging, requiring the combination of dynamic biochemical tests and multimodal imaging.
Since none of the dynamic tests show a perfect sensitivity and specificity, using more than one dynamic test might improve accuracy. A non-invasive approach using a combination of three or four tests, specifically CRH and desmopressin stimulation tests plus MRI, followed by total-body CT, if biochemical and anatomical findings are discordant, correctly diagnose CD in approximately half of patients, potentially eliminating the need for BIPSS [1784]. If a pituitary tumour is detected on MRI and dynamic testing results are consistent with CD, BIPSS is not necessary for diagnosis. Since ECS in children is extremely rare, the algorithm approach in children may differ from the adult approach. Findings of ACTH-dependent CS, doubtful CRH test and normal pituitary MRI should be followed by extended imaging (whole-body CT/MRI or functional imaging). Considering the extremely rarity of ECS, the great majority of ACTH-dependent hypercortisolism, even with normal pituitary MRI, corresponds to CD due to a pituitary lesion not yet visible [17]. For this reason, BIPSS should be used only exceptionally in children. A diagnostic algorithm is proposed in Fig. 1.

Conclusions

We provide detailed revision on the diagnostic evaluation of children and adolescents presenting with signs and symptoms suspicious for CS and guidance on the workup from the confirmation of endogenous hypercortisolism to the etiological diagnosis of such a rare challenging condition.

Declarations

Ethical approval

This article does not include research on human participants and/or animals.
Informed consent is not required.

Conflict of interest

The authors have no relevant financial or non-financial interests to disclose.
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Clinical Features and Treatment Options for Pediatric Adrenal Incidentalomas

Abstract

Background

The aim of this study was to investigate the clinical features and treatment options for pediatric adrenal incidentalomas(AIs) to guide the diagnosis and treatment of these tumors.

Methods

The clinical data of AI patients admitted to our hospital between December 2016 and December 2022 were collected and retrospectively analyzed. All patients were divided into neonatal and nonneonatal groups according to their age at the time of the initial consultation.

Results

In the neonatal group, 13 patients were observed and followed up, and the masses completely disappeared in 8 patients and were significantly reduced in size in 5 patients compared with the previous findings. Four patients ultimately underwent surgery, and the postoperative pathological diagnosis was neuroblastoma in three patients and teratoma in one patient. In the nonneonatal group, there were 18 cases of benign tumors, including 9 cases of ganglioneuroma, 2 cases of adrenocortical adenoma, 2 cases of adrenal cyst, 2 cases of teratoma, 1 case of pheochromocytoma, 1 case of nerve sheath tumor, and 1 case of adrenal hemorrhage; and 20 cases of malignant tumors, including 10 cases of neuroblastoma, 9 cases of ganglioneuroblastoma, and 1 case of adrenocortical carcinoma.

Conclusions

Neuroblastoma is the most common type of nonneonatal AI, and detailed laboratory investigations and imaging studies are recommended for aggressive evaluation and treatment in this population. The rate of spontaneous regression of AI is high in neonates, and close observation is feasible if the tumor is small, confined to the adrenal gland and has no distant metastasis.

Peer Review reports

Background

The incidence of adrenal incidentaloma (AI) is increasing due to the increased frequency of imaging and improved imaging sensitivity [1]. AI is relatively common in adults, and several organizations, such as the American Association of Clinical Endocrinologists/American Association of Endocrine Surgeons and the European Society Endocrinology, have proposed specific protocols to guide the evaluation, treatment, and follow-up management of AI in adults [2]. Although AI, a nonfunctioning adrenocortical adenoma, is most common in adults, neuroblastoma is the most common incidental tumor of the adrenal gland in children. In addition, in the neonatal period, which is a more complex stage of childhood, the biology of adrenal masses found in this age group is also more specific, and the nature of these masses can range from spontaneous regression to rapid progression to aggressive disease with metastatic dissemination and even death. Given that AI is the most common malignant tumor, the management of AI in children cannot be simply based on the measurements used in adult AI. In this study, we retrospectively analyzed the clinical data of pediatric AI patients in a single center to investigate the clinical characteristics and management of AI in children.

Methods

A total of 66 children with adrenal tumors were diagnosed and treated at the Department of Urology of the Children’s Hospital of Nanjing Medical University from December 2016 to December 2022. A total of 55 cases were detected during physical examination, or the patients were diagnosed and received treatment for diseases other than adrenal disease after excluding adrenal tumors detected due to typical clinical manifestations or signs such as centripetal obesity and precocious puberty. Research protocols involving human materials were approved by the Medical Ethics Committee of the Children’s Hospital of Nanjing Medical University. All clinical information, radiological diagnosis, laboratory test results, intervention results, and follow-up data were collected from the department’s database.

All the children underwent ultrasonography and CT scanning, and 11 children underwent MRI. In addition to routine tests such as blood routine and biochemical indexes, the examination and evaluation of adrenal endocrine hormones and tumor markers included (1) plasma cortisol and ACTH levels, (2) plasma catecholamine and metabolite determination, (3) plasma renin and plasma aldosterone, (4) urinary vanillylmandelic acid/homovanillic acid(VMA/HVA), and (5) AFP, CEA, NSE, and CA19-9. Five patients underwent a low-dose dexamethasone suppression test. Seventeen of the 55 patients were treated with watch-waiting therapy, 4 of the 17 ultimately underwent surgery, 4 of the 38 patients underwent tumor biopsy, and 34 underwent adrenalectomy.

The data were analyzed using Graph Pad Prism 8. The measurement data are expressed as ‾x ± sd. The maximum diameter of the tumors, age of the patients with benign and malignant tumors, and maximum diameter of the tumors between the laparoscopic surgery group and the open surgery group were compared using paired t tests, and the percentages of the count data were compared using Fisher’s exact test.

Results

In this study, all patients were divided into two groups according to their age at the time of consultation: the neonate group and the nonneonate group.

Neonate group:

There were 7 male and 10 female patients, 7 of whom were diagnosed via prenatal examination and 10 of whom were diagnosed after birth. Five patients were diagnosed with lesions on the left side, 12 patients were diagnosed with lesions on the right side, and the maximal diameters of the masses ranged from 16 to 48 mm. The characteristics of the AIs in the neonate group are presented in Table 1.

Table 1 Characteristics of AI in the neonates group

Among the 17 patients, 8 had cystic masses with a maximum diameter of 1648 mm, 5 had cystic-solid masses with a maximum diameter of 3339 mm, and 4 had solid masses with a maximum diameter of 1845 mm. Two patients with solid adrenal gland masses suggested by CT scan had obvious elevations in serum NSE and maximum diameters of 44 and 45 mm, respectively. These patients underwent adrenal tumor resection, and the pathology diagnosed that they had neuroblastomas(NB). In one patient, the right adrenal gland was 26 × 24 × 27 mm in size with slightly elevated echogenicity at 38 weeks after delivery, and the mass increased to a size of 40 × 39 × 29 mm according to the 1-month postnatal review. MRI suggested that the adrenal gland tumor was associated with liver metastasis, and the pathology of the tumor suggested that it was NB associated with liver metastasis after surgical resection (stage 4 S, FH). One child was found to have 25 × 24 × 14 mm cystic echoes in the left adrenal region during an obstetric examination, and ultrasound revealed 18 × 11 mm cystic solid echoes 5 days after birth. Ultrasound revealed 24 × 15 mm cystic solid echoes at 2 months. Serum NSE and urinary VMA were normal, and the tumor was excised due to the request of the parents. Pathology suggested a teratoma in the postoperative period. A total of 13 children did not receive surgical treatment or regular review via ultrasound, serum NSE or urine VMA. The follow-up time ranged from 1 to 31 months, with a mean of 9.04 ± 7.61 months. Eight patients had complete swelling, and 5 patients were significantly younger than the previous patients. Nonneonate group:

There were 24 male and 14 female patients in the nonneonate group; 24 patients had lesions on the left side, 14 patients had lesions on the right side, and the maximal diameters of the masses ranged from 17 to 131 mm. Most of these tumors were found during routine physical examinations or incidentally during examinations performed for various complaints, such as gastrointestinal symptoms, respiratory symptoms, or other related conditions. As shown in Table 2, abdominal pain was the most common risk factor (44.7%) for clinical onset, followed by routine physical examination and examination for respiratory symptoms.

Table 2 Clinical presentations leading to discovery of AI in non-neonate group

Among the 38 patients, 10 had NBs with maximum diameters ranging from 20 to 131 mm, 9 had ganglion cell neuroblastomas with maximum diameters ranging from 33.6 to 92 mm, 9 had ganglion cell neuromas with maximum diameters ranging from 33 to 62 mm, 2 had adrenal adenomas with maximum diameters ranging from 17 to 70 mm, 1 had a cortical carcinoma with a maximum diameter of 72 mm, 2 had adrenal cysts with maximum diameters ranging from 26 to 29 mm, 2 had mature teratomas with maximum diameters of 34 and 40 mm, 1 had a pheochromocytoma with a diameter of 29 mm, 1 had a nerve sheath tumor with a diameter of 29 mm, and 1 patient with postoperative pathological confirmation of partial hemorrhagic necrosis of the adrenal gland had focal calcification with a maximum diameter of 25 mm (Table 3).

Table 3 Distribution of different pathologies among AI with various sizes in non-neonate group

The mean age of children with malignant tumors was significantly lower than that of children with benign tumors (57.95 ± 37.20 months vs. 105.0 ± 23.85 months; t = 4.582, P < 0.0001). The maximum diameter of malignant tumors ranged from 20 to 131 mm, while that of benign tumors ranged from 17 to 72 mm, and the maximum diameter of malignant tumors was significantly greater than that of benign tumors (65.15 ± 27.61 mm v 37.59 ± 12.98 mm; t = 3.863, P = 0.0004). Four biopsies, 5 laparoscopic adrenal tumor resections and 11 open adrenal tumor resections were performed for malignant tumors, and 16 laparoscopic adrenal tumor resections and 2 open procedures were performed for benign tumors. The maximum diameter of the tumors ranged from 17 to 62 mm in 21 children who underwent laparoscopic surgery and from 34 to 99 mm in 13 children who underwent open resection; there was a statistically significant difference in the maximum diameter of the tumors between the laparoscopic surgery group and the open surgery group (35.63 ± 10.36 mm v 66.42 ± 20.60 mm; t = 5.798, P < 0.0001).

Of the 42 children with definitive pathologic diagnoses at surgery, 23 had malignant tumors, and 19 had benign tumors. There were 15 malignant tumors with calcification on imaging and 5 benign tumors. The percentage of malignant tumors with calcifications in was significantly greater than that of benign tumors (65.22% v 26.32%; P = 0.0157). In the present study, all the children underwent CT, and 31 patients had postoperative pathological confirmation of NB. A total of 26 patients were considered to have neurogenic tumors according to preoperative CT, for a diagnostic compliance rate of 83.97%. Three children were considered to have cortical adenomas by preoperative CT, and 1 was ultimately diagnosed by postoperative pathology, for a diagnostic compliance rate of 33.33%. For 4 patients with teratomas and adrenal cysts, the CT findings were consistent with the postoperative pathology. According to our research, NB 9-110HU, GNB 15-39HU, GB 19-38HU, ACA 8HU, adrenal cyst 8HU, and cellular achwannoma 17HU.

Discussion

According to the clinical practice guidelines developed by the European Society of Endocrinology and European Network for the Study of Adrenal Tumors, AI is an adrenal mass incidentally detected on imaging not performed for a suspected adrenal disease [3]. The prevalence of AI is approximately 4%, and the incidence increases with age [4]. Most adult AIs are nonfunctioning benign adrenal adenomas (up to 75%), while others include functioning adrenal adenomas, pheochromocytomas, and adrenocortical carcinomas [5]. In contrast to the disease spectrum of adult AI cases, NB is the most common tumor type among children with AI, and benign cortical adenomas, which account for the vast majority of adult AI, accounting for less than 0.5% of cases in children [6]. According to several guidelines, urgent assessment of an AI is recommended in children because of a greater likelihood of malignancy [37].

When an adult patient is initially diagnosed with AI, it should be clear whether the lesion is malignant and functional. In several studies, the use of noncontrast CT has been recommended as the initial imaging method for adrenal incidentaloma; a CT attenuation value ≤ 10 HU is used as the diagnostic criterion for benign adenomas; and these methods have a specificity of 71-79% and a sensitivity of 96-98% [89]. A CT scan of tumors with diameters greater than 4 to 6 cm, irregular margins or heterogeneity, a CT attenuation value greater than 10 HU, or a relative contrast enhancement washout of less than 40% 10 or 15 min after administration of contrast media on enhanced CT is considered to indicate potential malignancy [7]. As the most common AI in children, NB often appears as a soft tissue mass with uneven density on CT, often accompanied by high-density calcified shadows, low-density cystic lesions or necrotic areas. CT scans can easily identify more typical NBs, and for those AIs that do not show typical calcified shadows on CT, it is sometimes difficult to differentiate neurogenic tumors from adenomas. In these patients, except for the 1 patient with adrenal cysts who had a CT value of 8 HU, very few of the remaining AI patients had a CT value less than 10 HU. Therefore, the CT value cannot be used simply as a criterion for determining the benign or malignant nature of AI, and additional imaging examinations, such as CT enhancement, MRI, and FDG-PET if necessary, should be performed immediately for AI in children.

Initial hormonal testing is also needed for functional assessment, and aldosterone secretion should also be assessed when the patient is hypertensive or hypokalemic [7]. Patients with AI who are not suitable for surgery should be observed during the follow-up period, and if abnormal adrenal secretion is detected or suggestive of malignancy during this period, prompt adrenal tumor resection is needed. For adult patients with AI, laparoscopic adrenal tumor resection is one of the most effective treatments that has comparative advantages in terms of hospitalization time and postoperative recovery speed; however, there is still some controversy over whether to perform laparoscopic surgery for some malignant tumors with large diameters, especially adrenocortical carcinomas, and some studies have shown that patients who undergo laparoscopic surgery are more prone to peritoneal seeding of tumors [10].

The maximum diameter of an adult AI is a predictor of malignancy, and a study by the National Italian Study Group on Adrenal Tumors, which included 887 AIs, showed that adrenocortical carcinoma was significantly correlated with the size of the mass, and the sensitivity of detecting adrenocortical carcinoma with a threshold of 4 cm was 93% [11]. According to the National Institutes of Health, patients with tumors larger than 6 cm should undergo surgical treatment, while patients with tumors smaller than 4 cm should closely monitored; for patients with tumors between 4 and 6 cm, the choice of whether to be monitored or surgically treated can be based on other indicators, such as imaging [12]. A diameter of 4 cm is not the initial threshold for determining the benign or malignant nature of a mass in children.

In a study of 26 children with AI, Masiakos et al. reported that 9 of 18 benign lesions had a maximal diameter less than 5 cm, 4 of 8 malignant lesions had a maximal diameters less than 5 cm, and 2 had a diameter less than 3 cm. The mean maximal diameter of benign lesions was 4.2 ± 1.7 cm, whereas the mean maximum diameter of malignant lesions was 5.1 ± 2.3 cm. There was no statistically significant difference between the two comparisons; therefore, this study concluded that children with AI diameters less than 5 cm cannot be treated expectantly [6]. Additionally, this study revealed that malignant lesions occurred significantly more frequently than benign lesions in younger children (mean age 1.7 ± 1.8 years v 7.8 ± 5.9 years; P = 0.02).

In the nonneonatal group of this study, 20 patients with malignant tumors had maximum diameters ranging from 20 to 131 mm, 10 had malignant tumors larger than 60 mm, and 3 had tumors smaller than 40 cm; 18 patients with benign tumors had maximum diameters ranging from 17 to 70 mm, 5 had diameters ranging from 40 to 60 mm, and 5 had diameters larger than 60 mm. Therefore, it is not recommended to use the size of the largest diameter of the tumor to decide whether to wait and observe or intervene surgically for children with AI. Instead, it is necessary to consider the age of the child; laboratory test results, such as whether the tumor indices are elevated or not; whether the tumor has an endocrine function; etc.; and imaging test results to make comprehensive judgments and decisions. Preoperative aggressive evaluation and prompt surgical treatment are recommended for nonneonatal pediatric AI patients.

Adrenal hematoma and NBs are the most common types of adrenal area masses in children, while pheochromocytoma, adrenal cyst, and teratoma are rarer masses [13]. In clinical practice, adrenal hematoma and NB are sometimes difficult to differentiate, especially when adrenal masses are found during the prenatal examination and neonatal period, and such children need to be managed with caution. The Children’s Oncology Group (COG ANBL00B1) implemented the watchful waiting treatment for children under 6 months of age with a solid adrenal mass < 3.1 cm in diameter (or a cystic mass < 5 cm) without evidence of distant metastasis, and if there is a > 50% increase in the adrenal mass volume, there is no return to the baseline VMA or HVA levels, or if there is a > 50% increase in the urinary VMA/HVA ratio or an inversion, surgical resection should be performed [14]. Eighty-three children in this study underwent expectant observation, 16 of whom ultimately underwent surgical resection (8 with INSS stage 1 NB, 1 with INSS stage 2B, 1 with INSS stage 4 S, 2 with low-grade adrenocortical neoplasm, 2 with adrenal hemorrhage, and 2 with extralobar pulmonary sequestration). Most of the children who were observed had a reduced adrenal mass volume. Of the 56 patients who completed the final 90 weeks of expectant observation, 27 (48%) had no residual mass, 13 (23%) had a residual mass volume of 0–1 ml, 8 (14%) had a mass volume of 1–2 ml, and 8 (14%) had a volume of > 2 ml; ultimately, 71% of the residual masses had a volume ≤ 1 ml and 86% had a residual volume ≤ 2 ml. In this study, a total of 16 patients were included in the watchful waiting treatment group; 3 patients underwent surgical treatment during the follow-up period, and 13 patients ultimately completed watchful waiting treatment. After 1–31 months of follow-up, 8 patients’ swelling completely disappeared, and 5 patients’ swelling significantly decreased. After strict screening for indications and thorough follow-up review, AIs in the neonatal period can be subjected to watchful waiting treatment, and satisfactory results can be achieved.

For benign adrenal tumors, laparoscopic surgery is superior to open surgery in terms of successful resection, whereas the feasibility of minimally invasive surgery for AI with preoperative suspicion of malignancy is controversial. The European Cooperative Study Group for Pediatric Rare Tumors recommends that minimally invasive surgery be considered only for early childhood tumors and should be limited to small, localized tumors; additionally, imaging should suggest no invasion of surrounding tissue structures or lymph nodes; and this strategy requires surgeons with extensive experience in oncologic and adrenal surgery [15]. NB is the most common pediatric AI, and open tumor resection remains the mainstay of treatment. For small, early tumors without evidence of invasion on preoperative examination, laparoscopic resection may be considered if the principles of oncologic surgery can be adhered to. If the patient responds to chemotherapy, the decision to perform laparoscopic tumor resection can also be re-evaluated after chemotherapy. According to the current study, the recurrence and mortality rates of laparoscopic surgery are comparable to those of open surgery [1617]. The relative contraindications for laparoscopic NB resection include a tumor diameter greater than 6 cm, venous dilatation, and the involvement of adjacent organs or blood vessels [18]. Patients who undergo open adrenalectomy have higher overall survival and recurrence-free survival rates than patients who undergo laparoscopic adrenalectomy [19]. Open adrenalectomy remains the gold standard for surgical resection of adrenocortical carcinoma, whereas laparoscopic adrenalectomy should be reserved for highly selected patients and performed by surgeons with appropriate expertise [20].

Cortical tumors are particularly rare among children with AIs and are sometimes not clearly distinguishable from neurogenic tumors on preoperative imaging; in such patients, the presence of subclinical Cushing’s syndrome needs to be carefully evaluated preoperatively; otherwise, a perioperative adrenal crisis may occur [21]. In patients in whom the possibility of an adrenocortical tumor was considered preoperatively, the assessment for subclinical Cushing’s syndrome mainly involved assessing the serum dehydroepiandrosterone sulfate level and performing an overnight dexamethasone suppression test.

A procedure for evaluating pediatric AI is shown in Fig. 1. Imaging is the first step in the evaluation of AI in children. CT can be used to clarify the nature of most tumors. MRI can be used to evaluate imaging risk factors (IDRFs) for NB. Bone marrow cytomorphology is recommended for all children with AI, along with microscopic residual neuroblastoma testing and further bone scanning if the bone marrow examination is positive. In addition, serum tumor marker levels and other relevant tests should be performed, and hormone levels should be evaluated. If adrenal adenomas cannot be completely excluded during the preoperative examination, a 1 mg overnight dexamethasone suppression test should be performed to exclude subclinical Cushing’s syndrome. In patients with hypertensive hypokalemia, the presence of aldosteronism should be evaluated by testing plasma aldosterone concentrations and plasma renin activity. Adrenal masses found in the neonatal period can be observed if the tumor is small, confined to the adrenal gland and shows no evidence of distant metastasis, while tumors that increase significantly in size during the follow-up period or that are associated with persistently elevated tumor markers require aggressive surgical treatment.

Fig. 1

figure 1

Algorithm for the evaluation and management of a pediatric adrenal incidentaloma. *DST overnight :20µg/kg dexamethasoneweight ˂40 kg,1 mg dexamethasone if ≥ 40 kg. CT = computed tomographic;MRI = magnetic resonance imaging;NSE = neuron-specific enolase;AFP = alpha-fetoprotein;CEA = carcinoembryonic antigen;CA19-9 = cancerantigen19-9;ACTH = adrenocorticotropic hormone;PAC = plasma aldosterone concentration; PRA = plasma renin activity;DST = dexamethasone suppression test

Data availability

The datasets analyzed during the current study are not public, but are available from the corresponding author on reasonable request.

Abbreviations

CT:
computed tomographic
MRI:
magnetic resonance imaging
ACTH:
adrenocorticotropic hormone
VMA:
vanillylmandelic acid
HVA:
homovanillic Acid
AFP:
alpha-fetoprotein
CEA:
carcinoembryonic antigen
NSE:
neuron-specific enolase
CA19-9:
cancerantigen19-9
FH:
favorable histology
HU:
Hounsfiled Unit
COG:
Children’s Oncology Group
INSS:
International Neuroblastoma Staging System

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Acknowledgements

We would like to express our deepest gratitude to all the patients and their parents who participated in this study. Their patience and cooperation were instrumental to the success of this research. We thank our colleagues in the Department of Radiology for their invaluable contributions in diagnosing and monitoring the progression of adrenal incidentalomas. We sincerely appreciate the hard work of the pathologists in diagnosing and classifying tumors, which laid the foundation for our study. Finally, we would like to thank our institution for providing the necessary resources and an enabling environment to conduct this research.

Funding

Not applicable.

Author information

Authors and Affiliations

  1. Department of Urology, Children’s Hospital of Nanjing Medical University, 72 Guangzhou Road, Nanjing, 210008, Jiangsu, China

    Xiaojiang Zhu, Saisai Liu, Yimin Yuan, Nannan Gu, Jintong Sha, Yunfei Guo & Yongji Deng

Contributions

X.J.Z. and Y.J.D designed the study; S.S.L., Y.M.Y., N.N.G., and J.T.S. carried out the study and collected important data; X.J.Z. analysed data and wrote the manuscript; Y.F.G. and Y.J.D.gave us a lot of very good advices and technical support; All authors read and approved the final manuscript.

Corresponding author

Correspondence to Yongji Deng.

Ethics declarations

Competing interests

The authors declare no competing interests.

Ethics approval and consent to participate

Ethics approval for this study was granted by the Ethics Committee of Children’s Hospital of Nanjing Medical University. Informed written consent was obtained from all the guardians of the children and we co-signed the informed consent form with their parents before the study. We confirmed that all methods were performed in accordance with relevant guidelines and regulations.

Conflict of interest

There are no conflicts of interest.

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