Crinetics Pharma’s Promising Study on CRN04894 for Cushing’s Syndrome: A Potential Game-Changer?

Crinetics Pharmaceuticals is conducting a study titled ‘A Phase 1b/2a Open-label Multiple-ascending Dose Exploratory Study of CRN04894 in ACTH-dependent Cushing’s Syndrome.’ This study aims to evaluate the safety, tolerability, and pharmacokinetics of CRN04894, an ACTH receptor antagonist, in treating Cushing’s Syndrome, a condition characterized by excessive cortisol production. The study’s significance lies in its potential to offer a new treatment avenue for patients with Cushing’s disease or Ectopic ACTH Syndrome.

The intervention being tested is a drug named atumelnant, which is an orally active agent designed to block the action of ACTH at its receptor. This intervention is administered in tablet form and is intended to manage the symptoms of ACTH-dependent Cushing’s Syndrome.

The study employs an interventional design with a sequential model, featuring multiple ascending doses over 10 to 14 days. It is open-label, meaning there is no masking, and its primary purpose is treatment-focused, aiming to assess the drug’s effects on participants.

The study began on March 27, 2023, and is currently recruiting participants. The last update was submitted on April 8, 2025. These dates are crucial as they indicate the study’s progress and ongoing nature, which is essential for stakeholders tracking its development.

This clinical update could influence Crinetics Pharma’s stock performance positively by showcasing their commitment to advancing treatment options for Cushing’s Syndrome. Investors may view this as a promising development, potentially enhancing market sentiment. The study’s progress should be monitored alongside competitors in the endocrinology space to gauge its broader industry impact.

https://www.tipranks.com/news/company-announcements/crinetics-pharmas-promising-study-on-crn04894-for-cushings-syndrome-a-potential-game-changer

A Silent Invader: Asymptomatic Rhodococcus Infection Unmasked In a Patient With Ectopic ACTH-Dependent Cushing’s Syndrome

Introduction: Rhodococcus species, particularly Rhodococcus equi, are rare opportunistic pathogens that typically affect immunocompromised individuals. These infections usually present with respiratory or systemic symptoms and are often linked to environmental exposure. Asymptomatic Rhodococcus infections are exceedingly rare and pose unique diagnostic and therapeutic challenges.

Case description: We report the case of a 29-year-old male who presented with new-onset diabetes mellitus, resistant hypertension and significant weight gain. Physical examination revealed features consistent with Cushing’s syndrome. Biochemical evaluation confirmed ACTH-dependent hypercortisolism with an elevated plasma ACTH level, and a lack of suppression on high-dose dexamethasone testing; imaging identified a suspicious pulmonary nodule. Bronchoscopic biopsy revealed no malignancy, however cultures grew Rhodococcus species. The patient denied any respiratory symptoms or environmental exposure. Initial antibiotic therapy with ciprofloxacin and rifampin was started. Follow-up imaging showed rapid enlargement of the pulmonary mass, prompting surgical resection. Histopathology revealed malakoplakia, and repeat cultures again yielded Rhodococcus spp. Antibiotics were adjusted to azithromycin and rifampin, and the patient was started on ketoconazole to manage hypercortisolism.

Conclusion: This case highlights the importance of considering opportunistic infections such as Rhodococcus spp. in immunocompromised patients, even in the absence of symptoms. It underscores the diagnostic value of investigating incidental findings in such populations and illustrates the need for prompt, multidisciplinary management to prevent disease progression.

References

  • Prescott JF. Rhodococcus equi: an animal and human pathogen. Clin Microbiol Rev 1991;4:20–34. doi: 10.1128/CMR.4.1.20
    Search Crossref
  • Weinstock DM, Brown AE. Rhodococcus equi: an emerging pathogen. Clin Infect Dis 2002;34:1379–1385. doi: 10.1086/340259
    Search Crossref
  • Vázquez-Boland JA, Giguère S, Hapeshi A, MacArthur I, Anastasi E, Valero-Rello A. Rhodococcus equi: the many facets of a pathogenic actinomycete. Vet Microbiol 2013;167:9-33. doi: 10.1016/j.vetmic.2013.06.016
    Search Crossref
  • Álvarez-Narváez S, Huber L, Giguère S, Hart KA, Berghaus RD, Sanchez S, et al. Epidemiology and Molecular Basis of Multidrug Resistance in Rhodococcus equi. Microbiol Mol Biol Rev 2021;85:e00011-21. doi: 10.1128/MMBR.00011-21
    Search Crossref
  • Morton AC, Begg AP, Anderson GA, Takai S, Lämmler C, Browning GF. Epidemiology of Rhodococcus equi strains on Thoroughbred horse farms. Appl Environ Microbiol 2001;67:2167-2175. doi:10.1128/AEM.67.5.2167-2175.2001
    Search Crossref
  • von Bargen K, Haas A. Molecular and infection biology of the horse pathogen Rhodococcus equi. FEMS Microbiol Rev 2009;33:870–891. doi: 10.1111/j.1574-6976.2009.00181.x
    Search Crossref
  • Minnetti M, Hasenmajer V, Pofi R, Venneri MA, Alexandraki KI, Isidori AM. Fixing the broken clock in adrenal disorders: focus on glucocorticoids and chronotherapy. J Endocrinol 2020;246:R13–R31. doi: 10.1530/JOE-20-0066
    Search Crossref
  • Whitacre CC, Reingold SC, O’Looney PA. A gender gap in autoimmunity. Science 1999;283:1277–1278. doi: 10.1126/science.283.5406.1277
    Search Crossref
  • Yamshchikov AV, Schuetz A, Lyon GM. Rhodococcus equi infection. Lancet Infect Dis 2010;10:350–359. doi: 10.1016/S1473-3099(10)70068-2
    Search Crossref
  • Marsh HP, Bowler IC, Watson CJ. Successful treatment of Rhodococcus equi pulmonary infection in a renal transplant recipient. Ann R Coll Surg Engl 2000;82:107-108.
    Search Crossref
  • Ragnarsson O, Juhlin CC, Torpy DJ, Falhammar H. A clinical perspective on ectopic Cushing’s syndrome. Trends Endocrinol Metab 2024;35:347–360. doi: 10.1016/j.tem.2023.12.003
    Search Crossref

From https://www.ejcrim.com/index.php/EJCRIM/article/view/5711

Ectopic Adrenocorticotropic Hormone (ACTH)-Dependent Cushing Syndrome Secondary to Olfactory Neuroblastoma

Abstract

Background/Objective

Ectopic adrenocorticotropic hormone (ACTH)-dependent Cushing syndrome is a rare paraneoplastic disorder caused by excessive cortisol production from nonpituitary tumors. Olfactory neuroblastoma (ONB), a rare neuroendocrine malignancy of the sinonasal cavity, is an exceedingly uncommon source of ectopic ACTH production, with fewer than 25 cases reported worldwide. This report presents a case of ACTH-dependent Cushing syndrome due to ONB, emphasizing the diagnostic complexity, multidisciplinary management, and favorable clinical outcomes.

Case Presentation

A 70-year-old male presented with progressive muscle weakness, facial rounding, weight gain, hypertension, hypokalemia, and recurrent epistaxis. Laboratory evaluation revealed marked hypercortisolism and elevated plasma ACTH. Imaging demonstrated an expansile ethmoid sinus mass. Inferior petrosal sinus sampling excluded a pituitary source of ACTH. Endoscopic biopsy confirmed Hyams grade 2 ONB with positive immunohistochemical staining for neuroendocrine markers and ACTH. The patient received preoperative cortisol-lowering therapy and underwent complete endoscopic tumor resection followed by adjuvant radiotherapy. Postoperative assessment showed biochemical remission, resolution of Cushingoid features, and eventual recovery of the hypothalamic–pituitary–adrenal axis.

Discussion

This case highlights the importance of a systematic diagnostic approach that includes biochemical testing, imaging, inferior petrosal sinus sampling, and histopathology to identify ectopic ACTH sources. It demonstrates the necessity of collaboration among endocrinology, otolaryngology, neurosurgery, radiology, and oncology teams in managing rare ACTH-secreting tumors.

Conclusion

Timely diagnosis and definitive surgical resection of ACTH-producing ONB, along with endocrine stabilization and adjuvant radiotherapy, can lead to endocrine remission and improved long-term outcomes.

Key words

cushing syndrome
ectopic ACTH syndrome
neuroendocrine tumor
olfactory neuroblastoma
paraneoplastic syndrome

Abbreviations

ACTH

adrenocorticotropic hormone

AM

morning (ante meridiem)

DDAVP

desmopressin acetate

DHEA-S

dehydroepiandrosterone sulfate

EAS

ectopic ACTH syndrome

ENT

otolaryngology

IPSS

inferior petrosal sinus sampling

ONB

olfactory neuroblastoma

UFC

urinary free cortisol

Highlights

  • Rare case of ectopic adrenocorticotropic hormone syndrome secondary to olfactory neuroblastoma
  • Diagnostic challenges highlighted, including nondiagnostic inferior petrosal sinus sampling results
  • Multidisciplinary approach enabled complete tumor resection and hormonal remission
  • Preoperative ketoconazole minimized perioperative cortisol-related morbidity
  • Adjuvant radiotherapy optimized local control in intermediate-risk olfactory neuroblastoma

Clinical Relevance

This case emphasizes the importance of recognizing olfactory neuroblastoma as a rare source of ectopic adrenocorticotropic hormone production. It demonstrates the value of integrated biochemical, radiologic, surgical, and histopathologic strategies to achieve endocrine remission and prevent recurrence.

Introduction

Ectopic ACTH syndrome (EAS) is a rare paraneoplastic disorder resulting in ACTH-dependent hypercortisolism, which manifests clinically as Cushing syndrome. Although it accounts for approximately 10% to 15% of ACTH-dependent cases, EAS is most frequently caused by bronchial carcinoids, small cell lung carcinoma, and pancreatic neuroendocrine tumors.1,2 In contrast, olfactory neuroblastoma (ONB), also known as esthesioneuroblastoma—a neuroendocrine malignancy of the upper nasal cavity—is a highly uncommon cause, with fewer than 1% of ONB cases associated with EAS.2,3
ONB arises from the olfactory epithelium and represents 2% to 3% of all sinonasal cancers.4,5 Its nonspecific presentation—ranging from nasal obstruction to epistaxis or anosmia—can delay diagnosis, and advanced tumors may invade adjacent structures such as the orbit or anterior cranial fossa.4,5 Histological overlap with other small round blue cell tumors necessitates immunohistochemical markers such as synaptophysin, chromogranin A, and S-100 for accurate identification.4,6 Factors such as age may influence tumor behavior, treatment selection, and prognosis.7
When ONB presents with ectopic ACTH secretion, the resulting hypercortisolism can lead to profound metabolic and cardiovascular complications.8,9 Due to its extreme rarity, this combination may not be initially suspected, delaying targeted therapy. This report presents a rare case of ACTH-dependent Cushing syndrome caused by ONB, highlighting the diagnostic complexity and need for multidisciplinary management.3,10

Case Presentation

A 70-year-old male presented with 6 weeks of progressively worsening generalized, proximal muscle weakness, intermittent headaches, recurrent nosebleeds, abdominal fullness, leg swelling, and an unexplained 20-pound (9.1 kg) weight gain.
His medical history includes asthma, benign prostatic hyperplasia, hyperlipidemia, and retained shrapnel in the neck from military service in Vietnam. He has no history of hypertension, diabetes, or smoking. His family history includes a father who suffered a myocardial infarction at 51 years old, a mother with rheumatoid arthritis and osteoporosis, and a maternal uncle with lupus. His current medications include rosuvastatin 5 mg daily, tamsulosin 0.4 mg daily, and an albuterol inhaler as needed.
On examination, his vital signs were notable for an elevated blood pressure of 171/84 mmHg (normal: <120/<80 mmHg), a temperature of 37.2 C (99 F) (normal: 36.1–37.2°C [97–99 F]), a heart rate of 91 bpm (normal: 60–100 bpm), a respiratory rate of 16 breaths per minute (normal: 12–20 breaths per minute), an oxygen saturation of 92% on room air (normal: ≥95%), and a weight of 78.9 kg (174 lb). Physical examination revealed a round plethoric face (“moon facies,”) a prominent dorsocervical fat pad (“buffalo hump,”) supraclavicular fullness, mild abdominal tenderness, violaceous striae across the abdomen, diffuse soft tissue swelling, and bilateral 2+ pitting edema in the lower extremities.

Diagnostic Assessment

Laboratory evaluation demonstrated severe hypokalemia (1.6 mEq/L [1.6 mmol/L]; normal: 3.5–5.0 mEq/L [3.5–5.0 mmol/L]) and marked fasting hyperglycemia (244.0 mg/dL [13.5 mmol/L]; normal: 70–99 mg/dL [3.9–5.5 mmol/L]), in addition to leukocytosis, hypochloremia, acute kidney injury, hypoproteinemia, and hypoalbuminemia.
Hormonal evaluation (Table 1) was consistent with ACTH-dependent hypercortisolism, characterized by elevated serum cortisol and ACTH concentrations, lack of suppression with dexamethasone, and suppressed dehydroepiandrosterone sulfate (DHEA-S). Aldosterone and plasma renin activity were within normal limits, effectively excluding primary hyperaldosteronism. Plasma free metanephrines and normetanephrines were also within reference ranges, ruling out pheochromocytoma. Repeat morning cortisol remained markedly elevated, and late-night salivary cortisol levels on 2 occasions were significantly above the reference range. Twenty-four-hour urinary free cortisol (UFC) was profoundly elevated on both collections. Following a 1 mg overnight dexamethasone suppression test, serum cortisol, ACTH, and dexamethasone levels confirmed a lack of cortisol suppression despite adequate dexamethasone absorption (Table 1). These results were consistent with ACTH-dependent Cushing syndrome.

Table 1. Hormone Panel Results

Test Value Normal Range
AM cortisol 29 μg/dL (800.11 nmol/L) (high) 3.7–19.4 μg/dL (102–535 nmol/L)
Repeated AM cortisol 26 μg/dL (717.34 nmol/L) (high) 3.7–19.4 μg/dL (102–535 nmol/L)
ACTH 250 pg/mL (30.03 pmol/L) (high) 10–60 pg/mL (2.2–13.2 pmol/L)
Plasma renin activity 1.2 ng/mL/h (1.2 μg/L/h) (normal) 0.2–4.0 ng/mL/h (0.2–4.0 μg/L/h)
DHEA-S 50 μg/dL (1.25 μmol/L) (low) 65–380 μg/dL (1.75–10.26 μmol/L)
Aldosterone, blood 4. 9 ng/dL (0.14 nmol/L) (normal) 4.0–31.0 ng/dL (110–860 pmol/L)
Plasma free metanephrines 0.34 nmol/L (0.034 μg/L) (normal) <0.50 nmol/L (<0.09 μg/L)
Plasma free normetanephrines 0.75 nmol/L (0.075 μg/L) (normal) <0.90 nmol/L (<0.16 μg/L)
Late-night salivary cortisol (1st) 0.27 μg/dL (7.45 nmol/L) (high) ≤0.09 μg/dL (≤2.5 nmol/L) (10 PM–1 AM)
Late-night salivary cortisol (2nd) 0.36 μg/dL (9.93 nmol/L) (high) ≤0.09 μg/dL (≤2.5 nmol/L) (10 PM–1 AM)
24-h urinary free cortisol (1st) 5880.0 μg/d (16 223 nmol/d) (high) ≤60.0 μg/d (≤165 nmol/d)
24-h urinary free cortisol (2nd) 4920.0 μg/d (13 576 nmol/d) (high) ≤60.0 μg/d (≤165 nmol/d)
AM cortisol level (after 1 mg dexamethasone) 12.3 μg/dL (339 nmol/L) (high) <1.8 μg/dL (<50 nmol/L) adequate suppression
Dexamethasone level(after 1 mg dexamethasone) 336 ng/dL (8.64 nmol/L) (normal) >200 ng/dL (>5.2 nmol/L) adequate absorption
ACTH level (after 1 mg dexamethasone) 242 pg/mL (53.27 pmol/L) (not suppressed) 10–60 pg/mL (2.2–13.2 pmol/L)
Abbreviations: μg/d = micrograms per day; μg/dL = Micrograms per deciliter; μg/L = micrograms per liter; μmol/L = micromoles per liter; AM = morning (Ante Meridiem); nmol/L = nanomoles per Liter; ng/mL/h = nanograms per milliliter per hour; pmol/L = picomoles per liter; pg/mL = picograms per milliliter; μg/L/h = micrograms per liter per hour; ng/dL = nanograms per deciliter; nmol/d = nanomoles per day.
Inferior petrosal sinus sampling (IPSS) was performed using contrast-enhanced fluoroscopy to confirm accurate catheter placement in both inferior petrosal sinuses. Absolute ACTH values obtained during IPSS are shown in (Table 2). The central-to-peripheral ACTH gradient at baseline was 1.1, which is below the diagnostic threshold of 2.0 typically required to support a pituitary source of ACTH. Following desmopressin acetate (DDAVP) stimulation, peak left: peripheral and right: peripheral ACTH ratios reached 1.7 and 1.5, respectively—well below the accepted post-stimulation cut-off of 3.0. In addition, the left: right petrosal ACTH ratios remained between 1.03 and 1.15 throughout the sampling period, indicating no significant lateralization of ACTH secretion. These findings are not consistent with Cushing’s disease and instead support a diagnosis of ectopic ACTH syndrome.

Table 2. Bilateral Petrosal Sinus and Peripheral Adrenocorticotropin Levels Before and After Intravenous Injection of Desmopressin Acetate (DDAVP) 10 mcg

Time post DDAVP, min Left petrosal ACTH Left: peripheral ACTH Right petrosal ACTH Right: peripheral ACTH Peripheral ACTH Left: right petrosal ACTH
0 165 pg/mL (36.3 pmol/L) 1.1 160 pg/mL (35.2 pmol/L) 1.1 150 pg/mL (33.0 pmol/L) 1.03
3 270 pg/mL (59.4 pmol/L) 1.6 245 pg/mL (53.9 pmol/L) 1.4 170 pg/mL (37.4 pmol/L) 1.10
5 320 pg/mL (70.4 pmol/L) 1.7 285 pg/mL (62.7 pmol/L) 1.5 185 pg/mL (40.7 pmol/L) 1.12
10 350 pg/mL (77.0 pmol/L) 1.4 305 pg/mL (67.2 pmol/L) 1.2 250 pg/mL (55.0 pmol/L) 1.15
Abbreviations: ACTH = adrenocorticotropin; DDAVP = desmopressin acetate; pg/mL = picograms per milliliter; pmol/L = picomoles per liter.
Magnetic resonance imaging of the head could not be performed due to a history of retained shrapnel in the neck from combat in Vietnam. Noncontrast computed tomography (CT) images of the head and paranasal sinuses revealed no evidence of a pituitary tumor but demonstrated an expansile mass measuring approximately 2.4 × 4.3 × 3.3 cm, centered within the bilateral ethmoid sinuses with extension into both the anterior and posterior ethmoidal air cells (Fig. 1A, B). A contrast-enhanced CT scan of the abdomen, performed following improvement in renal function, demonstrated marked bilateral adrenal gland enlargement (Fig. 1C).

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Fig. 1. (A) Axial and (B) coronal noncontrast computed tomography (CT) images of the head demonstrate a heterogeneous soft tissue mass at the anterior skull base extending toward the cribriform plate and into the right nasal cavity, involving the ethmoid sinus and eroding the lamina papyracea, resulting in medial displacement of the right orbital contents (blue arrows). (C) Axial contrast-enhanced CT of the abdomen reveals bilateral adrenal gland enlargement. (D) Whole-body single-photon emission computed tomography/computed tomography (SPECT/CT) using indium-111 pentetreotide demonstrates intense radiotracer uptake localized to the biopsy-confirmed esthesioneuroblastoma in the ethmoid sinuses, with no evidence of metastatic octreotide-avid lesions. (G) Coronal contrast-enhanced CT scan of the abdomen, performed after surgery, shows normalization in the size of both adrenal glands. (E) Coronal and (F) axial noncontrast CT images of the paranasal sinuses obtained postoperatively demonstrate complete surgical resection of the tumor.

The otolaryngology (ENT) team was consulted and recommended an endoscopic biopsy of the nasal mass. Histopathologic examination revealed a Hyams Grade 2 olfactory neuroblastoma (Fig. 2A, B), characterized by well-circumscribed lobules of small round blue cells with scant cytoplasm, a neurofibrillary background matrix, and low mitotic activity, without necrosis or rosette formation—findings typical of a moderately differentiated tumor in the Hyams grading system.

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Fig. 2. (A) Low-power H&E (4×) shows well-circumscribed lobules of small round blue cells with fibrovascular stroma and a neurofibrillary matrix; no necrosis or rosettes are seen. (B) High-power H&E (40×) reveals neoplastic cells with high nuclear-to-cytoplasmic ratio, hyperchromatic nuclei, and granular chromatin, consistent with Hyams Grade 2 ONB. (C) Chromogranin A shows granular cytoplasmic positivity in tumor nests, confirming neuroendocrine differentiation. (D) Synaptophysin shows diffuse granular cytoplasmic staining in tumor clusters, with negative stromal background. (E) S-100 highlights sustentacular cells in a peripheral pattern around tumor nests. (F) ACTH staining shows patchy to diffuse cytoplasmic positivity in tumor cells, confirming ectopic ACTH production in ONB. A nuclear medicine octreotide scan (111 Indium-pentetreotide scintigraphy) with single-photon emission computed tomography/computed tomography (SPECT/CT) demonstrated intense radiotracer uptake in the biopsy-proven esthesioneuroblastoma centered within the ethmoid sinuses, confirming the tumor’s expression of somatostatin receptors. There was no evidence of locoregional or distant metastatic disease demonstrating octreotide avidity (Fig. 1D).

Immunohistochemical staining supported the diagnosis: tumor cells were positive for chromogranin A (Fig. 2C), synaptophysin (Fig. 2D), and S-100 (Fig. 2E). Chromogranin A and synaptophysin are markers of neuroendocrine differentiation, confirming the tumor’s neuroendocrine origin. S-100 positivity in the sustentacular cells surrounding tumor nests is a classic feature of olfactory neuroblastoma. Staining was negative for neurofilament protein, AE1/AE3, and epithelial membrane antigen, helping exclude other small round blue cell tumors, such as neuroendocrine carcinoma or sinonasal undifferentiated carcinoma. Importantly, the tumor cells showed positive cytoplasmic staining for ACTH (Fig. 2F), confirming ectopic ACTH production by the tumor itself. This finding definitively links the olfactory neuroblastoma as the source of paraneoplastic ACTH secretion, consistent with the patient’s clinical picture of ectopic Cushing’s syndrome.

Treatment

Hypokalemia was corrected, and oral ketoconazole 200 mg twice daily was initiated preoperatively to mitigate the metabolic complications of hypercortisolism. Ketoconazole was discontinued on the day of surgery. The tumor was resected via an endoscopic endonasal approach. A blood sample was obtained immediately following tumor removal for measurement of ACTH and cortisol levels. Intravenous hydrocortisone (100 mg every 6 h) was initiated promptly thereafter. Postoperative cortisol and ACTH levels were undetectable: cortisol <5 μg/dL [<138 nmol/L] (normal: 5–25 μg/dL [138–690 nmol/L]); ACTH <5 pg/mL [<1.1 pmol/L] (normal: 10–60 pg/mL [2.2–13.3 pmol/L]). These findings confirmed successful surgical resection of the ACTH-secreting tumor. These issues extended the hospital stay and required treatment with antiseizure medications, antibiotics, and additional surgeries by ENT and Neurosurgery teams.

Outcome and Follow-Up

The patient demonstrated significant normalization of blood pressure (124/78 mmHg), fasting blood glucose (95 mg/dL [5.3 mmol/L]), and potassium (4.3 mEq/L [4.3 mmol/L]) within 2 weeks postoperatively. ACTH levels decreased from preoperative values of 220–250 pg/mL (48.4–55.2 pmol/L) to 29 pg/mL (5.5 pmol/L), and morning (AM) cortisol levels decreased from preoperative values of 29 μg/dL (800 nmol/L) to 12 μg/dL (331 nmol/L). These values were obtained at 2 weeks postoperatively. While early normalization of ACTH and cortisol levels could raise concern for residual disease, the patient’s subsequent sustained biochemical remission, clinical recovery, and a robust response to cosyntropin stimulation at 3 months post-op were reassuring. Adjuvant radiotherapy was also administered to mitigate any potential risk of recurrence.
He was subsequently transferred to an inpatient rehabilitation facility while receiving oral hydrocortisone replacement therapy, during which his functional status progressively improved. The patient was later discharged home on oral hydrocortisone replacement therapy with plans for continued outpatient physical therapy. Hydrocortisone was gradually tapered and discontinued 3 months after surgery, at which point blood pressure (122/76 mmHg), fasting glucose (90 mg/dL [5.0 mmol/L]), potassium (4.2 mEq/L [4.2 mmol/L]), ACTH (25 pg/mL [4.9 pmol/L]), and AM cortisol (15 μg/dL [414 nmol/L]) demonstrated sustained normalization. Following administration of 250 mcg intramuscular cosyntropin, serum cortisol peaked at 21 μg/dL (580 nmol/L), confirming an adequate adrenal reserve and complete recovery of the hypothalamic–pituitary–adrenal axis. Additionally, late-night salivary cortisol was remeasured on 2 occasions after hydrocortisone discontinuation and found to be 0.04 μg/dL (1.10 nmol/L) and 0.03 μg/dL (0.83 nmol/L), both within normal reference limits (≤0.09 μg/dL [≤2.5 nmol/L]). A 24-hour UFC collected at the same time measured 38 μg/d (105 nmol/d), confirming biochemical resolution of hypercortisolism. Cushing’s stigmata, including muscle weakness and skin changes, showed marked improvement by 3 months postoperatively (Table 3).

Table 3. Timeline of Clinical and Biochemical Recovery Following Resection of Ectopic ACTH-Secreting Olfactory Neuroblastoma

Parameter Preoperative value 24–48 h Postop 2 wks postop 3 mo postop Normal range
Blood pressure 171/84 mmHg 140/80 mmHg 124/78 mmHg 122/76 mmHg <130/80 mmHg
Fasting glucose 244 mg/dL (13.5 mmol/L) 160 mg/dL (8.9 mmol/L) 95 mg/dL (5.3 mmol/L) 90 mg/dL (5.0 mmol/L) 70–99 mg/dL (3.9–5.5 mmol/L)
Potassium 1.6 mEq/L (1.6 mmol/L) 3.8 mEq/L (3.8 mmol/L) 4.3 mEq/L (4.3 mmol/L) 4.2 mEq/L (4.2 mmol/L) 3.5–5.0 mEq/L (3.5–5.0 mmol/L)
ACTH 220–250 pg/mL (48.4–55.2 pmol/L) <10 pg/mL (<2.2 pmol/L) 29 pg/mL (5.5 pmol/L) 25 pg/mL (4.9 pmol/L) 10–60 pg/mL (2.2–13.3 pmol/L)
AM cortisol 29 μg/dL (800 nmol/L) <5 μg/dL (<138 nmol/L) 12 μg/dL (331 nmol/L) 15 μg/dL (414 nmol/L); Cosyntropin peak: 21 μg/dL (580 nmol/L) 5–25 μg/dL (138–690 nmol/L); adequate response >18 μg/dL (500–550 nmol/L)
LNSC 0.27/0.36 μg/dL (7.45/9.93 nmol/L) 0.04/0.03 μg/dL (1.10/0.83 nmol/L) ≤0.09 μg/dL (≤2.5 nmol/L) (10 PM–1 AM)
UFC (24-h) 5880/4920 μg/d (16 223/13 576 nmol/d) 38 μg/d (105 nmol/d) ≤60 μg/d (≤165 nmol/d)
Cushing’s Stigmata Moon facies, dorsocervical fat pad, violaceous striae, severe muscle weakness No change Partial improvement: BP/glucose control; decreased edema Marked improvement; muscle strength restored; striae fading Not applicable
Abbreviations: ACTH = adrenocorticotropin; mmHg = illimeters of mercury; mEq/L = milliequivalents per liter; mg/dL = milligrams per deciliter; mmol/L = millimoles per liter; μg/dL = micrograms per deciliter; AM = morning (Ante Meridiem); pg/mL = picograms per milliliter; pmol/L = picomoles per liter; nmol/L = nanomoles per liter.
dfA follow-up CT scan of the adrenals with contrast, performed following improvement in renal function, confirmed normalization in the size of the previously enlarged adrenal glands (Fig. 1E). A follow-up CT of sinuses without contrast confirmed complete resection of the tumor (Fig. 1F, G).
Adjuvant radiotherapy was recommended in view of the patient’s Kadish stage B tumor, Hyams grade 2 histology, and the elevated risk of local recurrence inherent to olfactory neuroblastoma. Despite complete surgical excision, radiotherapy was pursued to mitigate recurrence risk, particularly considering the tumor’s ectopic ACTH secretion, which suggested biologically aggressive behavior, as well as the patient’s satisfactory functional status and anticipated favorable treatment tolerance. A total of 30 fractions of 2 Gy were administered using volumetric modulated arc therapy.

Discussion

Diagnostic Considerations

EAS poses a significant diagnostic challenge due to its variable presentation and the urgency of identifying the source of ACTH excess. ONB, although rare, should be considered in patients with ACTH-dependent Cushing syndrome who present with sinonasal masses. ONB accounts for only 2% to 3% of all malignant sinonasal tumors,4,6 with fewer than 25 cases documented as sources of ectopic ACTH production.3,11,12
While ectopic ACTH syndrome remains the most well-recognized endocrine manifestation of ONB, a broader spectrum of paraneoplastic syndromes has also been described. These include syndrome of inappropriate antidiuretic hormone secretion, paraneoplastic hypercalcemia—often mediated by parathyroid hormone–related protein—and catecholamine excess mimicking pheochromocytoma.11 These atypical presentations underscore the neuroendocrine complexity of ONB and the diagnostic challenges they pose.
Diagnosis involves biochemical confirmation of hypercortisolism using low-dose dexamethasone suppression, 24-hour UFC, late-night salivary cortisol, and plasma ACTH levels. Interestingly, despite markedly elevated ACTH levels, our patient exhibited a low DHEA-S concentration and a normal aldosterone level. This biochemical pattern supports previous observations that EAS may present with a dissociation in adrenal steroidogenesis. Chronic hypercortisolemia may suppress the zona reticularis,13 while ectopic ACTH-producing tumors may secrete aberrant precursors that preferentially stimulate glucocorticoid rather than androgen synthesis.14 Cortisol excess can also downregulate key enzymes such as 17,20-lyase and SULT2A1, thereby impairing DHEA-S production.15 Moreover, the rapid onset and severity of ectopic ACTH production may preclude the compensatory DHEA-S rise typically observed in pituitary-driven Cushing disease. Although cortisol excess is known to suppress the renin-angiotensin-aldosterone system, aldosterone levels may remain detectable in certain EAS cases, particularly in early-stage or physiologically variable presentations.16
Once ACTH-dependence is established, localization of the tumor becomes essential. IPSS, although considered the gold standard for distinguishing pituitary from ectopic ACTH sources, may yield inconclusive results in cases of ONB due to altered venous drainage pathways.3 Functional imaging with 111In-octreotide single-photon emission computed tomography/computed tomography or 68Ga-DOTATATE positron emission tomography/computed tomography facilitates localization of neuroendocrine tumors that express somatostatin receptors. Histopathologic confirmation using ACTH immunostaining and neuroendocrine markers such as chromogranin A, synaptophysin, and S-100 is essential to confirm diagnosis.

Therapeutic Approach and Challenges

Surgical resection remains the cornerstone of management for ACTH-producing ONB.9 Endoscopic endonasal approaches are preferred when anatomically feasible due to their minimally invasive nature and favorable access to the anterior skull base. Preoperative pharmacologic inhibition of cortisol biosynthesis (utilizing ketoconazole, which was specifically selected for our patient, metyrapone, or etomidate) represents a critical intervention to attenuate hypercortisolism-related metabolic complications and minimize perioperative morbidity.3,8 Intraoperative glucocorticoid replacement should be administered following tumor resection to prevent adrenal insufficiency. Postoperative complications—such as cerebrospinal fluid leak or infection—require prompt multidisciplinary intervention.
Adjuvant radiotherapy is generally recommended for intermediate-to high-grade ONBs, even after gross total resection, given their aggressive behavior and high risk of recurrence. Volumetric modulated arc therapy delivers precise radiation doses while minimizing toxicity to adjacent structures.5,9 Platinum-based chemotherapy remains a therapeutic option in patients with unresectable or metastatic disease.9
Emerging therapeutic strategies include somatostatin receptor–directed theranostics. Zhi et al (2025) recently demonstrated the dual diagnostic and therapeutic potential of 68Ga-DOTATATE positron emission tomography/computed tomography imaging and 177Lu-DOTATATE peptide receptor radionuclide therapy in ONB, offering promising future directions for patients with advanced or somatostatin receptor–positive disease.17

Prognosis and Future Directions

The prognosis of ONB is influenced by Kadish staging, Hyams histologic grading, and treatment strategy. Recurrence rates are reported to range from 30% to 60%,9,18 and 5-year survival rates vary from 45% to 80% depending on tumor grade, stage, and completeness of resection.6,19 Early detection, complete surgical resection, and multimodal therapy, including radiotherapy, are associated with improved outcomes. Lifelong follow-up with serial imaging and endocrine evaluation is essential to monitor for recurrence and late-onset adrenal insufficiency.10,19
Continued advancements in molecular imaging and targeted therapies, particularly those leveraging somatostatin receptor biology, may expand the therapeutic landscape for patients with recurrent or progressive ONB.

Conclusion

This case highlights the importance of timely diagnosis, comprehensive biochemical and radiologic assessment, and coordinated multidisciplinary management in ACTH-producing ONB. In addition to surgery and preoperative endocrine stabilization, adjuvant radiotherapy and long-term surveillance are critical components of care. As somatostatin receptor–based imaging and theranostic therapies evolve, they offer exciting opportunities to individualize treatment in this rare but challenging neuroendocrine malignancy.

Statement of Patient Consent

Written informed consent was obtained from the patient for publication of this case report and any accompanying images.

Disclosure

The author has no conflict of interest to disclose.

References

Adrenal Gland Volume Measurement Could Assist Surgery Option in Patients With Primary Pigmented Nodular Adrenocortical Disease

Abstract

Background

Primary pigmented nodular adrenocortical disease is a rare form of adrenocorticotropic hormone–independent Cushing syndrome originating from bilateral adrenal lesions. Current guidelines do not specify a recommended strategy for determining the optimal surgery. This study evaluates the concordance between bilateral adrenal gland volume and adrenal venous sampling results and the predictive value of adrenal gland volume for postoperative outcomes in patients with primary pigmented nodular adrenocortical disease.

Method

This is a retrospective study conducted at a single center. The study cohort included 10 hospitalized patients with primary pigmented nodular adrenocortical disease from 2011 to 2023. Patients underwent thin-slice adrenal computed tomography scan. An nnU-NET–based automatic segmentation model segmented the adrenal region of interest, and adrenal gland volume were computed. The ratio of left to right adrenal gland volume were also determined. All patients underwent either unilateral or bilateral adrenalectomy and received postoperative follow-up.

Results

Adrenal gland volume enlargement was asymmetrical between the 2 sides. Larger adrenal gland volumes typically corresponded to the side of dominant cortisol production as indicated by adrenal venous sampling. Clinical and biochemical remission was achieved with left adrenalectomy when left to right adrenal gland volume exceeded 1.2, and with right adrenalectomy when left to right adrenal gland volume was below 0.9. When the left to right adrenal gland volume was approximately 1, unilateral adrenalectomy proved less effective, often necessitating bilateral adrenalectomy, either simultaneously or sequentially.

Conclusion

Measuring adrenal gland volume can aid in formulating the optimal surgical approach for patients with primary pigmented nodular adrenocortical disease.

Introduction

Primary pigmented nodular adrenocortical disease (PPNAD) is an uncommon cause of adrenocorticotropic hormone (ACTH)-independent Cushing syndrome (ACS).1 Frequently, PPNAD is associated with the Carney complex (CNC), a rare multiple endocrine neoplasia syndrome characterized by distinctive pigmented lesions on skin and mucous membranes, cardiac and extracardiac myxomas, and multiple endocrine tumors.2 Approximately 45–68.6% of patients with CNC develop PPNAD. CNC is most commonly linked to mutations in the PRKAR1A gene, which follows an autosomal-dominant inheritance pattern, although approximately 25% of cases emerge sporadically from de novo mutations.1,2
The adrenal morphology in PPNAD typically includes multiple small nodules forming a “string of beads” appearance1; however, some patients exhibit atypical features such as a normal adrenal contour, unilateral large nodules, or adenomas.3, 4, 5 In cases lacking other CNC components, these atypical features increase the risk of diagnostic errors.
To date, no universally endorsed surgical strategies exist for PPNAD. Although bilateral adrenalectomy was once the standard treatment to eliminate autonomous cortisol secretion, it leads to lifelong adrenal insufficiency, necessitating continuous glucocorticoid and mineralocorticoid replacement, and poses an ongoing risk of adrenal crisis.1 Accumulating evidence suggests that unilateral adrenalectomy can diminish cortisol levels and ameliorate metabolic disturbances associated with glucocorticoid excess, with some patients experiencing temporary adrenal insufficiency.1,6 This suggests that cortisol production may not be synchronously increased in bilateral adrenals in patients with PPNAD. Selecting the dominant cortisol-producing adrenal for resection could control the metabolic effects of autonomous cortisol production while avoiding the need for lifelong hormone replacement and the risk of an adrenal crisis.
Bilateral adrenal venous sampling (AVS), typically used to identify the dominant aldosterone-secreting side in primary aldosteronism,7 also has been employed to determine the dominant cortisol-secreting side in PPNAD, thus guiding surgical decisions.8,9 However, AVS is technically demanding, involves radiation exposure, has a notable failure rate, and is costly. Moreover, there are no standardized criteria for successful AVS or for determining the dominant side in patients with PPNAD. Therefore, exploring simpler, cost-effective, and reliable criteria for surgical decision-making is crucial.
In this study, we included previously diagnosed patients with PPNAD to apply machine-learning algorithms for segmenting adrenal region of interest (ROI) and analyze the relationship between adrenal morphologic changes and clinical outcomes, thereby providing guidance for surgical planning.

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Patients and diagnoses

From December 2011 to August 2024, 321 patients with ACS were diagnosed and treated in the Department of Endocrinology and Metabolism at West China Hospital of Sichuan University. Among them, 12 patients with PPNAD were identified, and 10 of them with preoperative adrenal computed tomography (CT) imaging, comprising 2 male and 8 female patients, were included in this study. Among them, 8 patients were found to carry PRKAR1A gene mutations, as identified by next-generation sequencing of DNA

Patient clinical characteristics

The study analyzed data from 10 patients, comprising 8 women and 2 men, with a mean age of 30.5 years (range, 15–55 years). Eight patients were diagnosed with arterial hypertension, 4 exhibited impaired glucose regulation, and 2 had normal glucose levels and arterial blood pressure. Nine patients displayed typical features of Cushing syndrome, with the exception of 1 individual who presented solely with hypertension and central obesity. In addition, all female participants experienced menstrual

Discussion

This retrospective study examined the relationships among AGV, AVS, and surgical outcomes in 10 patients diagnosed with PPNAD. We observed that AGVs in patients with PPNAD were not uniformly enlarged. Variability in enlargement was noted, with some patients developing larger left adrenal lesions, others larger right adrenal lesions, and some exhibiting equivalently sized bilateral adrenal lesions. Generally, larger AGVs correlated with the dominant side of cortisol production as indicated by

Funding/Support

The study was supported by a grant from the Science &Technology Department of Sichuan Province (2023YFS0262) and a grant from the Ministry of Science and Technology of the People’s Republic of China (2022YFC2505303).

CRediT authorship contribution statement

Tao Chen: Writing – review & editing, Writing – original draft, Visualization, Validation, Software, Resources, Project administration, Methodology, Investigation, Funding acquisition, Formal analysis, Data curation, Conceptualization. Sikui Shen: Resources, Project administration, Investigation. Yeyi Tang: Resources. Wei Xie: Resources. Huaiqiang Sun: Software, Methodology, Data curation. Yuchun Zhu: Resources. Mingxi Zou: Resources. Ying Chen: Resources. Haoming Tian: Supervision. Xiaomu Li:

Conflict of Interest/Disclosure

The authors have no relevant financial disclosures.

References (18)

  • K.L. Hackman et al.

    Cushing syndrome in a young woman due to primary pigmented nodular adrenal disease

    Endocr Pract

    (2010)
  • G. Luo et al.

    An optimized two-stage cascaded deep neural network for adrenal segmentation on CT images

    Comput Biol Med

    (2021)
  • A.C. Powell et al.

    Operative management of Cushing syndrome secondary to micronodular adrenal hyperplasia

    Surgery

    (2008)
  • L. Bouys et al.

    Bilateral adrenocortical nodular disease and Cushing’s syndrome

    J Clin Endocrinol Metab

    (2024)
  • L. Bouys et al.

    Management of endocrine disease: carney complex: clinical and genetic update 20 years after the identification of the CNC1 (PRKAR1A) gene

    Eur J Endocrinol

    (2021)
  • L. Groussin et al.

    Mutations of the PRKAR1A gene in Cushing’s syndrome due to sporadic primary pigmented nodular adrenocortical disease

    J Clin Endocrinol Metab

    (2002)
  • K.M. Lowe et al.

    Cushing syndrome in carney complex: clinical, pathologic, and molecular genetic findings in the 17 affected mayo clinic patients

    Am J Surg Pathol

    (2017)
  • D. Vezzosi et al.

    Hormonal, radiological, NP-59 scintigraphy, and pathological correlations in patients with Cushing’s syndrome due to primary pigmented nodular adrenocortical disease (PPNAD)

    J Clin Endocrinol Metab

    (2015)
  • Y. Zhu et al.

    Primary pigmented nodular adrenocortical disease: report of 5 cases

    Chin Med J (Engl)

    (2006)
There are more references available in the full text version of this article.

High Recovery Rate of Adrenal Function After Successful Surgical Treatment of Cushing’s Syndrome

Abstract

Context

Successful first-line treatment of Cushing’s syndrome by resection of the underlying tumor is usually followed by adrenal insufficiency.

Purpose

The aims of this study were to determine the recovery rate and time to recovery of adrenal function after treatment for different forms of endogenous Cushing’s syndrome and to identify factors associated with recovery.

Methods

In this retrospective study of 174 consecutive patients with Cushing’s syndrome, the recovery rate and time to recovery of adrenal function after surgery were assessed.

Results

The 1-year, 2-year and 5-year recovery rates of patients with Cushing’s disease were 37.8, 70.1 and 81.1%, respectively. For patients with adrenal Cushing’s syndrome, the 1-year, 2-year and 5-year recovery rates were higher: 49.3, 86.9 and 91.3%, respectively. Median time to recovery for patients with Cushing’s disease and adrenal Cushing’s syndrome was 13.9 and 12.1 months, respectively. The median time to recovery of adrenal function in patients with Cushing’s disease with and without recurrence was 9.9 versus 14.4 months, respectively. Higher age was associated with a lower probability of recovery of adrenal function: HR 0.83 per decade of age (95% CI 0.70–0.98).

Conclusion

The recovery rate of adrenal function after successful surgery as first-line treatment in patients with Cushing’s syndrome is high. However, it may take several months to years before recovery of adrenal function occurs. In case of early recovery of adrenal function, clinicians should be aware of a possible recurrence of Cushing’s disease.

Introduction

Cushing’s syndrome (CS) is characterized by chronic exposure to an excess of glucocorticosteroids (1). Endogenous hypercortisolism is a rare disorder with an estimated incidence of 0.2–5 patients per million per year (1). CS can cause severe, disabling signs and symptoms and is associated with significantly increased morbidity and mortality. In approximately 70% cases, endogenous CS is caused by an ACTH-producing pituitary adenoma, also known as Cushing’s disease (CD). In 15–25% cases, an ACTH-independent form of CS is caused by a unilateral adrenal adenoma, adrenal carcinoma or bilateral micro- or macronodular hyperplasia (adrenal CS). An ACTH-producing ectopic tumor is a rare cause of CS. First-line treatment of CS is surgical removal of the pituitary, adrenal or ectopic tumor (12).

Successful first-line treatment by resection of the underlying tumor is usually followed by adrenal insufficiency (AI) due to suppression of the hypothalamic–pituitary–adrenal axis after prolonged exposure to high concentrations of cortisol (345). Theoretically, one would expect that the hypothalamic–pituitary–adrenal axis recovers over time and that the substitution of glucocorticosteroids can slowly be reduced and stopped as long as there is no irreversible damage to the remaining adrenal or pituitary tissue. However, in clinical practice, AI is not always transient. In a subset of patients, this is caused by permanent AI due to perioperative damage to the pituitary gland or irreversible atrophy of the contralateral adrenal gland. In other cases, tapering the dosage of glucocorticosteroids is not possible because this causes worsening of symptoms. Despite the glucocorticoid replacement therapy, patients often experience symptoms resembling AI, such as fatigue, myalgia, arthralgia, depression, anxiety and decreased quality of life, also known as glucocorticoid withdrawal syndrome (GWS) (6). GWS is caused by dependence on supraphysiologic glucocorticoid concentrations after chronic exposure to high concentrations of glucocorticoids, which can complicate and delay the withdrawal of exogenous steroids. As a result, patients and physicians often struggle with a dilemma: on the one hand, lowering the cortisol substitution is necessary to enable functional recovery of the hypothalamic–pituitary–adrenal axis. On the other hand, lowering the substitution therapy often causes worsening of symptoms. In clinical practice, it is not always possible to completely taper the substitution of steroids due to GWS, even in spite of intensive guidance and support by the treating physician, specialized nurse and other healthcare professionals. Moreover, in patients remaining on glucocorticoid replacement, it is not always clear whether the failure to recover from AI is caused by the irreversible damage of the remaining pituitary or adrenal tissue or the failure to overcome the GWS. The time after which adrenal function recovers and substitution therapy can be tapered off varies largely between patients but may take several years (7).

A recent survey among patients with CS highlighted the need of patients for better information about the difficult post-surgical course (8). However, scientific data about this post-operative period, particularly regarding the recovery rate and time to recovery from AI are scarce (91011121314151617181920). Because of the rarity of CS, most studies are hampered by a limited number of patients. The reported recovery rates of adrenal function after first-line treatment for CS vary widely, between 37 and 93% for CD (910111213) and between 38 and 93% for overt adrenal CS (101214151617).

The reported duration to recovery of the hypothalamic–pituitary–adrenal axis after CD and adrenal CS also varies widely, between 13 and 25 months after CD (910111319) and between 11 and 30 months in overt adrenal CS (101415161820).

Factors which influence the recovery rate and the duration to recovery of adrenal function are not entirely clear. A few studies reported a lower chance of recovery and a longer duration to recovery of adrenal function in patients who are younger, have more severe hypercortisolism, and longer duration of symptoms before diagnosis, whereas other studies could not confirm these findings (101321). By contrast, other studies reported a higher chance of recovery in younger patients (21). Identification of these factors may help provide patients with more information about the expected post-surgical course.

Therefore, the aims of the present study were to assess the recovery rate and time to recovery of adrenal function after successful first-line treatment in the different subtypes of CS in a large series of consecutive patients treated at a tertiary referral center and to identify factors associated with recovery.

Methods

Patients

The medical records of adult and pediatric patients treated for CS at Radboud University Medical Center, Nijmegen, between 1968 and 2022 were examined retrospectively. This is a tertiary referral hospital where practically all cases of CS from the large surrounding geographic area are managed. All patients with CD, adrenal CS and ectopic CS who were in remission and developed AI after first-line surgical treatment were included. Exclusion criteria were bilateral adrenalectomy as first-line treatment, adrenocortical carcinoma, radiotherapy of the pituitary gland before surgery, pituitary carcinoma and the therapeutic use of corticosteroids for conditions other than AI. Data were collected on age, sex, body mass index (BMI), duration of CS symptoms, comorbidities, the use of medication, biochemical results at diagnosis and during follow-up, preoperative imaging, surgical treatment and histology.

The study was assessed by the Committee for Research with Humans, Arnhem/Nijmegen Region and the need for written approval by individual patients was waived since this study did not fall within the remit of the Medical Research Involving Human Subjects Act (WMO). The study has been reviewed by the ethics committee on the basis of the Dutch Code of conduct for health research, the Dutch Code of conduct for responsible use, the Dutch Personal Data Protection Act and the Medical Treatment Agreement Act. The ethics committee has passed a positive judgment on the study. The procedures were conducted according to the principles of the Declaration of Helsinki.

Diagnostics and definitions

Patients were diagnosed with CS according to the guidelines available at the time, i.e., the presence of signs and symptoms of hypercortisolism in combination with confirmatory biochemical tests, including the 1 mg dexamethasone suppression test (DST), 24-h urine free cortisol (UFC), late-night salivary cortisol concentrations and/or hair cortisol. The cutoff value for adequate cortisol suppression after the DST was <50 nmol/L (22). For UFC, the times upper limit of normal was calculated because several assays with different reference values were used over time.

First-line treatment consisted of pituitary surgery in patients with CD and unilateral adrenalectomy in patients with ACS. In patients with bilateral macronodular hyperplasia, adrenalectomy of the largest adrenal was performed after carefully outweighing the risks and benefits of surgery together with the patient, taking into account factors such as age, severity of symptoms, comorbidities associated with hypercortisolism (e.g., diabetes mellitus type 2, cardiovascular disease, osteoporosis) and the severity of the hypercortisolism (2).

Peri- and postoperatively, all patients received glucocorticoid stress dosing, which was tapered off within a few days after surgery. Adrenal function was initially evaluated with a postoperative morning fasting cortisol concentration, measured at least 24 h after the last dose of hydrocortisone or cortisone acetate, within 7 days after surgery. If the postoperative morning fasting cortisol was <200 nmol/L, the patient was considered to have AI and glucocorticoid replacement therapy was continued. The starting dose was usually hydrocortisone 30 mg once daily (or an equivalent dose of cortisone acetate in the early years). For children, the dose was weight-based. Afterwards, the dose was slowly tapered off according to the symptoms/well-being of the patient and fasting cortisol values. During follow-up, the dose was usually divided into two or three doses a day.

Remission of CS after treatment was defined as either a morning cortisol of ≤50 nmol/L, adequate cortisol suppression after DST or a late-night salivary cortisol concentration within the reference range. Duration of AI was defined as the time between surgery and discontinuation of glucocorticoid replacement therapy. Complete recovery of adrenal function was assessed by spontaneous fasting cortisol concentration, an insulin tolerance test or a 250 μg ACTH stimulation test after discontinuation of glucocorticoid replacement therapy. In cases where fasting morning cortisol ≥520 nmol/L, adrenal function was considered as completely recovered. For the dynamic tests, assay-dependent cutoff values were used according to the guidelines available at the time. The dynamic tests were not performed routinely in all patients until 1999. In patients for whom no dynamic tests (results) were available, complete recovery of AI was defined as complete discontinuation of replacement therapy. Recurrence of CS was defined as the presence of signs and symptoms of hypercortisolism in combination with confirmatory biochemical tests, including the 1 mg DST, 24-h UFC, late-night salivary cortisol concentrations and/or hair cortisol.

Statistical analysis

Continuous data were expressed as mean ± SD or median + interquartile range (IQR), and categorical data were presented as frequency (n) and percentage (%). We produced Kaplan–Meier curves to determine the unadjusted probability of recovery of adrenal function over time. Patients that tapered off and completely stopped the glucocorticoid replacement therapy were assigned in the survival analyses as having an event (=recovery of adrenal function). The date of the last follow-up visit was assigned in the survival analyses as the last date and patients that were lost to follow-up or developed a recurrence before stopping the glucocorticoid replacement therapy were censored. In order to identify factors associated with recovery of adrenal function, we compared Kaplan Meier curves between several subgroups of patients: CD versus adrenal CS versus ectopic CS, age (at diagnosis) groups of ≤35 versus 36–55 versus ≥56 years old, patients with or without postoperative pituitary deficiencies, patients with or without recurrence of CS during follow-up, patients with or without preoperative medical treatment (PMT), patients operated before versus after 2010 and patients with a low versus slightly higher post-operative morning cortisol (<100 nmol/L versus 100–200 nmol/L), measured within 7 days after surgery. The Kaplan–Meier curves of the subgroups were compared using the two-sided log-rank test. The P-value ≤0.05 was considered statistically significant. The Kaplan–Meier curves provided the 1-year, 2-year and 5-year recovery rates and the median time to recovery of the adrenal gland. We used Cox proportional hazards models to calculate hazard ratios (HRs) with a 95% confidence interval (CI) of the probability of recovery of adrenal function over time in order to identify factors associated with recovery of adrenal function (univariate analyses). Cox proportional hazards models with multivariate analyses were performed to calculate the adjusted HRs with 95% CI. The model of multivariate analysis for the whole group included the variables: etiology of CS, age, sex, BMI, duration of symptoms before diagnosis, UFC and postoperative cortisol 0.10–0.20 versus <0.10 mcmol/L. The model of multivariate analysis for the patients with CD only included the variables: etiology of CD, age, sex, BMI, duration of symptoms before diagnosis, UFC, post-operative cortisol 0.10–0.20 versus <0.10 mcmol/L, PMT, hormonal deficiencies of the anterior pituitary gland other than AI and micro/macroadenoma. A 95% CI not including 1 was considered statistically significant.

All statistical analyses were performed using STATA version 11 (StataCorp, USA).

Results

In total, 174 patients were included in the analysis. The assessment of eligibility, the number of patients excluded from this study and the reasons for exclusion are shown in Fig. 1. The baseline characteristics are described in Table 1. The median follow-up was 6.8 years (IQR: 2.2–12.6). In 69.6% (94/135) of all patients who discontinued their glucocorticoid replacement therapy, the recovery of adrenal function was confirmed with a dynamic test or a morning cortisol concentration ≥520 nmol/L.

Figure 1View Full Size
Figure 1
Flowchart showing the assessment for eligibility, the number of patients excluded from the study and the reasons for exclusion.

Citation: Endocrine Connections 14, 5; 10.1530/EC-24-0612

Table 1Baseline characteristics.

Variable All patients CD Adrenal CS
Participants (n) 174 135 35
Female (%) 135/174 (77.6%) 102/135 (75.6%) 32/35 (91.4%)
Median age at diagnosis (y) 44 (35–55) 43 (32–55) 47 (36–54)
Median BMI at diagnosis (kg/m2) 28.3 (24.7–32.4) 28.6 (24.7–32.9) 28.0 (26.0–31.8)
Median duration of symptoms before diagnosis of CS (years) 3.0 (1.0–5.6) 3.0 (1.0–6.0) 3.5 (1.5–5.6)
Median times upper limit of normal UFC at diagnosis 3.7 (1.9–5.8) 3.9 (2.0–6.4) 2.4 (1.4–4.1)
Median cortisol after DST (nmol/L) 480 (320–630) 460 (290–620) 550 (330–710)
Median salivary cortisol at diagnosis (nmol/L) 8.6 (5.4–15.4) 10.1 (5.9–18.0) 6.1 (4.0–8.9)
Median follow up (years) 6.8 (2.2–12.6) 8.4 (3.0–13.5) 2.2 (1.2–4.7)
Preoperative medical therapy* (n) 120/174 (69%) 106/135 (78.5%) 10/35 (28.6%)
Pituitary microadenoma/macroadenoma/no adenoma detected on MRI scan (n) 64/27/28**
Bilateral disease (n) 7/35 (20.0%)

CD, Cushing’s disease; CS, Cushing’s syndrome; BMI, body mass index; UFC, 24-h urine free cortisol; DST, 1 mg dexamethasone suppression test. Continuous data are summarized as median and interquartile ranges. Categorical data are presented as frequencies and percentages.

*Cortisol-lowering medication, either metyrapone or ketoconazole.

**Missing data on MRI in 16 patients.

Recovery rates and recovery times of adrenal function

The probability of recovery of AI for CD, adrenal CS and ectopic CS are depicted in Fig. 2. The 1-year, 2-year and 5-year recovery rates of adrenal function for the entire cohort were 40.1, 73.4 and 83.3%, respectively. The median time to recovery of adrenal function was 13.9 months. The 1-year, 2-year and 5-year recovery rates of patients with CD were 37.8, 70.1 and 81.1%, respectively. The median recovery time was 13.9 months for patients with CD. For patients with adrenal CS, the 1-year, 2-year and 5-year recovery rates were higher: 49.3, 86.9 and 91.3%, respectively (two-sided log-rank test: P = 0.14). The median recovery time for patients with adrenal CS was 12.1 months. Seven out of the 35 patients with adrenal Cushing had bilateral disease. The median time to recovery in patients with bilateral disease was 17.5 versus 11.0 months in patients with unilateral disease.

Figure 2View Full Size
Figure 2
Cumulative probability of recovery of adrenal function in CD (n = 135), adrenal CS (n = 35) and ectopic Cushing (n = 4).

Citation: Endocrine Connections 14, 5; 10.1530/EC-24-0612

Of the 15 evaluated patients with ectopic CS, only four patients underwent successful resection of the ectopic tumor and were included in our study. All four patients had a neuroendocrine tumor of the lung and recovered from AI. The time to recovery of adrenal function was known in three patients: 5.7, 7.9 and 14.5 months.

Factors associated with recovery of adrenal function

Age at diagnosis

Figure 3 shows the Kaplan–Meier curves of three different age groups (group 1: 0–35 years old, group 2: 36–55 years old and group 3: 56–100 years old). The 1-year recovery rates of patients aged between 0–35, 36–55 and 56–100 years old were 54.6, 37.2 and 31.4%, respectively. The 2-year recovery rates were 79.3, 72.6 and 68.4%, respectively and the 5-years recovery rates were 89.6, 83.8 and 75.1%, respectively. The median times to recovery of adrenal function of patients aged between 0–35, 36–55 and 56–100 years old were 11.2, 13.4 and 17.6 months, respectively. The probability of recovery of AI was higher in young patients (0–35 years old) (two-sided log-rank test: P = 0.05).

Figure 3View Full Size
Figure 3
Cumulative probability of recovery of adrenal function by age groups.

Citation: Endocrine Connections 14, 5; 10.1530/EC-24-0612

Recurrence after primary treatment

In total, 17.8% patients with CD (24/135) had developed a recurrence during follow-up. Figure 4 shows the Kaplan–Meier curves with the probability of recovery of AI of the groups with and without recurrence during follow-up in patients with CD. The probability of recovery of AI was higher in patients with a recurrence (two-sided log-rank test: P-value = 0.02). In patients with a recurrence, the 1-, 2- and 5-year recovery rates of AI were 60.9, 78.3 and 87.0%, respectively. In patients without a recurrence, the 1-, 2- and 5-years recovery rates of AI were 32.6, 68.3 and 79.7%, respectively. The median time to recovery of adrenal function in patients with CD with and without recurrence was 9.9 versus 14.4 months, respectively.

Figure 4View Full Size
Figure 4
Cumulative probability of recovery of adrenal function by recurrence during follow-up in patients with CD.

Citation: Endocrine Connections 14, 5; 10.1530/EC-24-0612

There was only one patient with adrenal CS with a recurrence. This was a patient with bilateral macronodular hyperplasia. During the first surgery, the largest adrenal was removed. However, 3 years later, the contralateral adrenal was also removed because of the recurrence of CS.

Hypopituitarism after pituitary surgery

In patients with CD, we performed a sub-analysis based on the presence of anterior pituitary deficiencies after pituitary surgery for CD, besides AI. Antidiuretic hormone (ADH) deficiency was not included in this analysis. As expected after pituitary surgery and in line with the literature, temporary ADH deficiency occurred in a substantial part of the patients after surgery (23). Therefore, only central hypothyroidism, hypogonadotropic hypogonadism and growth hormone deficiency were taken into account (Fig. 5). The probability of recovery of AI was lower in patients with one or more pituitary deficiencies versus patients with intact pituitary function after surgery (two-sided log-rank test: P-value = 0.05). In patients with anterior pituitary deficiencies, the 1-, 2- and 5-years recovery rates of AI were 35.6, 60.4 and 67.6%, respectively. In patients without anterior pituitary deficiencies, the 1-, 2- and 5-years recovery rates of AI were 39.2, 76.0 and 89.1%, respectively. The median time to recovery of adrenal function in patients with CD with and without anterior pituitary deficiencies was 15.9 versus 13.4 months, respectively. Figure 6 shows the Kaplan–Meier curves by the number of hormonal deficiencies of the anterior pituitary gland, other than AI. Although statistical significance was not reached, there is a trend showing that the more postoperative hormonal deficiencies present, the lower the probability of recovery of AI is (two-sided log-rank test: P-value = 0.15).

Figure 5View Full Size
Figure 5
Kaplan–Meier curve by the presence/absence of hormonal deficiencies of the anterior pituitary gland (other than AI) after surgery in patients with CD.

Citation: Endocrine Connections 14, 5; 10.1530/EC-24-0612

Figure 6View Full Size
Figure 6
Kaplan–Meier curve by the number of hormonal deficiencies of the anterior pituitary gland after surgery in patients with CD.

Citation: Endocrine Connections 14, 5; 10.1530/EC-24-0612

Preoperative cortisol-lowering medical therapy, year of surgery and fasting cortisol concentration at the initial postoperative evaluation

Sub-analyses regarding patients who received PMT versus patients without PMT did not show any difference in the probability of recovery. In patients without PMT, the 1-, 2- and 5-years recovery rates of AI were 42.6, 77.6 and 85.2%, respectively. In patients with PMT, the 1-, 2- and 5-years recovery rates of AI were 41.6, 73.7 and 82.3%, respectively. The median time to recovery of adrenal function in patients without PMT and with PMT was 14.1 versus 13.5 months, respectively.

Sub-analyses regarding patients operated on before versus after 2010, regarding the results of the 1 mg dexamethasone suppression test at diagnosis and regarding patients with a low versus slightly higher postoperative morning cortisol within 7 days after surgery (<100 versus 100–200 nmol/L) also did not show any difference in the probability of recovery of adrenal function.

Table 2 shows HRs of univariate and multivariate Cox regression analyses. Adrenal CS and ectopic CS were associated with a higher probability of recovery of AI in comparison with patients with CS. Higher age was associated with a lower probability of recovery of AI.

Table 2Uni- and multivariate Cox regression analyses.

Variable Univariate Cox regression Multivariate Cox regression
HR 95% CI P value HR 95% CI P value
Etiology of CS (CD/adrenal CS/ectopic) 1.44 1.00–2.08 0.05 1.76 1.11–2.80 0.02
Etiology of CS (CD/adrenal CS) 1.42 0.91–2.22 0.12
Age (decades) 0.81 0.71–0.93 0.002 0.83 0.70–0.98 0.03
Sex (male/female) 1.02 0.68–1.55 0.92 0.74 0.46–1.20 0.22
BMI (kg/m2) 1.00 0.97–1.02 0.81 1.01 0.97–1.05 0.61
Duration of symptoms before diagnosis (years) 0.95 0.90–1.01 0.08 0.95 0.89–1.01 0.09
UFC (ULN) 1.03 0.99–1.07 0.15 1.01 0.97–1.05 0.57
Post-operative cortisol 0.10–0.20 versus <0.10 mcmol/L 0.92 0.56–1.50 0.73 1.16 0.58–2.30 0.67
In patients with CD only
PMT (no/yes) 1.23 0.75–2.02 0.40 1.26 0.53–3.02 0.60
Hormonal deficiencies of the anterior pituitary gland, other than AI (no/yes) 0.65 0.43–0.99 0.05 0.67 0.40–1.11 0.12
Micro/macroadenoma 1.13 0.70–1.83 0.62 1.42 0.79–2.52 0.24

PMT, preoperative medical treatment; HR, hazard ratio; CI, confidence interval; CS, Cushing’s syndrome; CD, Cushing’s disease; BMI, body mass index; UFC (ULN), times upper limit 24-h urine free cortisol; AI, adrenal insufficiency. The model of multivariate analysis for the whole group included the variables: etiology of CD, age, sex, BMI, duration of symptoms before diagnosis, UFC and postoperative cortisol 0.10–0.20 versus <0.10 mcmol/L. The model of multivariate analysis for the patients with CD only included the variables: etiology of CD, age, sex, BMI, duration of symptoms before diagnosis, UFC, postoperative cortisol 0.10–0.20 versus <0.10 mcmol/L, preoperative medical treatment, hormonal deficiencies of the anterior pituitary gland other than AI and micro/macroadenoma.

Discussion

In this study, we investigated the recovery rate of adrenal function and time to recovery after first-line treatment in patients with CS. The main finding is that the recovery rates of adrenal function are high. However, it may take several months to years before recovery of adrenal function occurs.

Patients with adrenal CS had higher recovery rates than patients with CD. This can be explained by the fact that the cortisol excess is generally less severe in adrenal CS and the fact that one adrenal gland remains completely intact after unilateral adrenalectomy. By contrast, patients who undergo pituitary surgery are at risk of developing new pituitary hormone deficiencies, including corticotrope deficiency, due to permanent structural damage to the pituitary gland. Our finding that patients with additional pituitary deficiencies after surgery for CD had lower recovery rates of adrenal function supports this hypothesis.

The recovery rates of adrenal function in CD, as well as in adrenal CS, are higher than what was reported in some previous studies (101112), but are similar to other reports (13151718). As shown in Table 3, it is difficult to compare previous studies because they all differ in design, study population and inclusion and exclusion criteria. For example, Berr et al. and Klose et al. used a different cutoff value of postoperative cortisol (<100 nmol/L) than we did (<200 nmol/L) to define initial AI shortly after surgery. However, only 25 patients in our cohort had a postoperative morning cortisol between 100 and 200 nmol/L and sub-analysis of patients with a morning cortisol <100 nmol/L versus patients with a morning cortisol between 100 and 200 nmol/L did not show any difference in recovery rate or time. Another difference between studies is the strategy for tapering off and stopping glucocorticoids in the postoperative period. In our study, patients started with 30 mg hydrocortisone per day after surgery. One might expect that a higher dose of hydrocortisone leads to a longer time to recovery of adrenal function. However, there are no data or evidence-based guidelines regarding the best strategy for tapering off and stopping glucocorticoids in the postoperative period.

Table 3Overview of previous studies regarding recovery of adrenal function after surgery in patients with CS.

Author n, etiology Recovery rate AI Time to recovery, years Follow up years Definition of AI/remission Substitution therapy (start doses) Recurrence rate (CD)
Alexandraki, 2013 (8) 131 CD 49/81 (60.5%) during follow up Median 1.5 years Minimum 6 years, mean 15.9 ± 6 years Postoperative cortisol ≤50 nmol/L Prednisolone 5 + 2 mg or HC 20 mg in divided doses 22.7% (microadenoma) 33.3% macroadenoma
Berr, 2015 (9) 5-year: Median: Mean 8.2 years Morning cortisol ≤100 nmol/L HC 40–50 mg/day
54 CD CD: 58% CD: 1.4 years CD: 7.0 years
26 ACS ACS: 38% ACS: 2.5 years ACS: 8.5 years
11 ECS ECS: 82% ECS: 0.6 years ECS: 13.5 years
Serban, 2019 (12) 61 CD 5-year: Median 1.6 years Minimum 3 years, median 6 years Morning cortisol ❤ μg/dL or cortisol after 250 μg synacthen test <18 μg/dL Cortisone acetate 25 mg, divided in 2–3 doses 16.4%
Persistent remission: 55.8% 2.1 years
Recurrence: 100% 1.0 years
Ciric 2012 (10) 86 CD 59.3% during follow up Mean 1.1 years Minimum 0.5 years, mean 5.7 years Drop in immediate postoperative cortisol, range <0.5–5.3 µg/dL and symptoms No specific unified algorithm 9.7%
Klose, 2004 (11) 2-year: Median: Post-operative cortisol <100 nmol/L and/or UFC <50 nmoL/24h Hydrocortisone 20–30 mg/day
18 CD CD: 67% CD: 2 years CD: 22.2%
14 ACS ACS: 79% ACS: 2 years ACS: 0%
Prete, 2017 (18) Median: Minimum 2 years Postoperative morning serum cortisol <5 μg/dL/138 nmol/L Hydrocortisone 20–30 mg/day in divided in 2–3 doses Patients with recurrence were excluded
15 CD CD: 1.3 years CD: median 5.8 years
31 ACS ACS: 0.8 years ACS: Median 4.0 years
 14 overt ACS Overt ACS: 1.5 years
 17 subclinical ACS Subclinical ACS: 0.5 years
Hurtado, 2018 (14) 81 ACS 87.8% during follow up Median ACS: 0.4 years Median ACS: 1.2 years Postoperative morning (day 1) serum cortisol <10 μg/dL/276 nmol/L or hemodynamic instability or received perioperative GC due to anticipated AI after unilateral adrenalectomy Prednisone or hydrocortisone, median hydrocortisone-equivalent dose 40 mg/day
 27 severe CS Severe: 1.0 years Severe: 1.0 years
 24 moderate CS Moderate: 0.2 years Moderate: 1.0 years
 30 MACE MACE: 0.2 years MACE: 1.5 years
Dalmazi, 2014 review on adrenal function after adrenalectomy for subclinical CS, 28 studies (17) ACS: 376 overt ACS 141 subclinical ACS Overt ACS: 93.4% subclinical ACS: 97.9% Mean overt ACS: 0.9 years subclinical ACS 0.5 years

CD, Cushing’s disease; ACS, adrenal Cushing’s syndrome; ECS, ectopic Cushing’s syndrome; AI, adrenal insufficiency; Subclin: subclinical; MACE, mild autonomous cortisol excess.

One might also hypothesize that the studies reporting high recurrence rates are related to higher recovery rates in CD patients. In our study, the recurrence rate was 17.8%, which is in line with previous studies (91324). The establishment of recovery of adrenal function in patients with a recurrence later on is a difficult matter: despite the exclusion of patients with immediate obvious persistent disease in our study, recovery of glucocorticoid secretion in patients who developed a recurrence later on could be an early manifestation of recurrence instead of true recovery of physiological adrenal function. A striking finding in this study, in line with the aforementioned hypothesis, was the considerably higher 1-year recovery rate and the shorter time to recovery of patients with a recurrence in comparison to patients without a recurrence. Recovery of adrenal function is more rapid in patients with recurrences (1325). These findings imply that in case of an early recovery of adrenal function, clinicians should be aware of a possible recurrence of CD.

Another difference between studies is the inclusion or exclusion of patients with mild autonomous cortisol secretion (MACS), formerly known as subclinical CS. Previous studies have shown that patients with subclinical CS have a higher probability of recovery and a shorter duration of AI (14151618). In our study, only two patients were diagnosed with subclinical CS (in this study characterized as inadequate suppression after DST in combination with values of UFC within the reference range) and therefore subgroup analysis was not possible.

In the present study, a rather high number of patients received PMT in comparison to other studies. In our institution, it was common practice to start PMT 3 months before pituitary surgery in patients with CD with the aim to improve hemostasis and other Cushing-related comorbidities, although the benefit of PMT has not yet been well established by randomized controlled trials. At the liberty of the treating physician, the dose of ketoconazole or metyrapone was titrated with the aim to normalize the 24-h UFC excretion. The doses needed to achieve normal 24-h UFC and the time to normalization of 24-h UFC varied between patients.

One could hypothesize that lowering cortisol levels during the weeks to months before surgery may result in a faster recovery of adrenal function. However, this was not the case in this study.

Overall, the present study shows a high recovery rate of adrenal function after treatment for CS. The time until recovery is partly dependent on the strategy and success of tapering off of glucocorticoids replacement and therefore may be very long because of GWS. These are meaningful findings. Tapering glucocorticoid substitution in parallel with the recovery of cortisol secretion after surgery for CS is often a challenging and lengthy trajectory for both patients and physicians. The lack of standardization of the follow-up and of the tapering protocols, the need for constant shared decision-making and personalized support for patients, particularly of those who are also confronted with severe associated comorbidities and unpredictable withdrawal symptoms, may discourage patients and physicians from proceeding in this endeavor. Given the rarity of the disease, knowledge on this topic is scarce. Previous, mainly smaller studies reported a wide range of recovery rates of adrenal function after first-line treatment for CS (varying between 37 and 93% for CD, and for overt adrenal CS between 38 and 93%) (10111213151718). The rather low percentages of recovery of adrenal function in some of these previous studies could discourage patients and physicians to persevere the attempt to taper off hydrocortisone. Our findings in a large cohort of patients with CS, including a sizable subgroup of patients with CD, allow us to deepen the multivariate analysis to uncover factors that are associated with a better chance of recovery. The data indicate that in this real-life setting, despite the long time to achieve recovery, the recovery rates are high and while this occurs for most of the patients within 1–2 years after treatment, recovery is still possible even after a longer follow-up. Moreover, this study showed that the recovery rate is higher in patients with adrenal CS versus CD, in younger patients and in patients with CD with preserved pituitary function after pituitary surgery. These findings are very important for clinical practice. They highlight the importance of continuing to taper off the glucocorticoids, if necessary slowly and steadily, in the years after surgery. They also help us better inform the patients beforehand and to improve the management and the expectations of both patients and physicians to motivate them to persevere in tapering of the glucocorticosteroids while considering the factors such as those identified to influence the chance of recovery during their personalized counseling and guidance of the patients in this often very difficult and lengthy period.

In our institution, it is common practice to counsel and provide guidance intensively to patients in this difficult period, both by the treating physician and a specialized nurse, as we consider this coordinated guidance of utmost importance. Moreover, all patients are provided with contact details so that they can reach to us for advice 24 h a day, either by phone or by secure email throughout this process. When indicated, patients are referred to other healthcare professionals such as psychologists, physical therapists, social workers and other specialists.

One important strength of our study is the large size of our single-center cohort, considering the rarity of the disease. This has also allowed us to do subgroup analyses and assess factors associated with recovery from postoperative AI. The limitations include the retrospective character of this study and the fact that patients were included over a long period of time (1968 to 2022) during which diagnostic tools and management protocols for CS have somewhat changed over this period of time. We have tried to mitigate the limitations that are inevitable with a retrospective study by being thorough and extensive in the quality and amount of data that we were able to collect. In addition to that, the diagnostic assessment and the treatment of the patients followed very strict and uniform protocols in conformity with the internationally recognized clinical guidelines available at the time. On the other hand, the fact that this represents a real-life study renders the results more relatable for clinical practitioners and strengthens its impact.

We collected data from medical records regarding the duration of CS-related signs and symptoms before diagnosis, as mentioned by the patient during history taking. We are well aware that these data are rather subjective and dependent on the accuracy of the recollection of the patient. However, this is the only way to assess the duration of symptoms before diagnosis. In our opinion, these data still could be very valuable.

In conclusion, our study shows that the large majority of patients with CS recover their adrenal function after first-line surgical treatment, even though the time to recovery may take several months to years. Informing patients beforehand and providing support, encouragement and guidance in this process is therefore paramount. Herewith, one could consider factors such as the age of the patient, the etiology of CS and the presence of additional pituitary deficiencies after pituitary surgery. In case of an early recovery of adrenal function, clinicians should be aware of a possible recurrence of CD. Future studies should establish the optimal postoperative management for CS to improve the chance for success of recovery of adrenal function.

Declaration of interest

The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the work reported.

Funding

This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.

References