Spontaneous Cushing’s Disease Remission Induced by Pituitary Apoplexy

Abstract

Spontaneous remission of Cushing’s disease (CD) is uncommon and often attributed to pituitary tumor apoplexy. We present a case involving a 14-year-old female who exhibited clinical features of Cushing’s syndrome. Initial diagnostic tests indicated CD: elevated 24h urinary cortisol (235 µg/24h, n < 90 µg/24h), abnormal 1 mg dexamethasone overnight test (cortisol after 1 mg dex 3.4 µg/dL, n < 1.8 µg/dL), and elevated adrenocorticotropic hormone concentrations (83.5 pg/mL, n 10-60 pg/mL). A pituitary adenoma was suspected, so a nuclear MRI was performed, with findings suggestive of a pituitary microadenoma. The patient was referred for a transsphenoidal resection of the microadenoma. While waiting for surgery, the patient presented to the emergency department with a headache and clinical signs of meningism. A computed axial tomography of the central nervous system was performed, and no structural alterations were found. The symptoms subsided with analgesia. One month later, she presented again to the emergency department with clinical findings of acute adrenal insufficiency (cortisol level of 4.06 µg/dL), and she was noted to have spontaneous biochemical remission associated with the resolution of her symptoms of hypercortisolism. For that reason, spontaneous CD remission induced by pituitary apoplexy (PA) was diagnosed. The patient has been managed conservatively since the diagnosis and remains in clinical and biochemical remission until the present time, after 10 months of follow-up. There are three unique aspects of our case: the early age of onset of symptoms, the spontaneous remission of CD due to PA, which has been rarely reported in the medical literature, and the fact that the patient presented a microadenoma because there are fewer than 10 clinical case reports of PA associated with microadenoma.

Introduction

Cushing’s disease (CD) is characterized by excessive production of adrenocorticotropic hormone by a pituitary adenoma and represents the most common cause of endogenous Cushing’s syndrome (CS) [1]. CD was first reported in 1912 by Harvey Williams Cushing, and he described 12 cases at the Peter Bent Brigham Hospital in Baltimore [2]. This disease has a global incidence of approximately 2.2 cases per 1,000,000 people and occurs more frequently in women from 20 to 50 years of age [3]. Pituitary apoplexy (PA) is a rare condition that occurs in 2-12% of cases, and it has a high morbidity and mortality rate [4]. We report an interesting case of a woman diagnosed with CD who achieved spontaneous remission of her disease after a PA.

Case Presentation

A 14-year-old female presented with a two-year history of weight gain (32 kg), depression, elevated blood pressure, type 2 diabetes mellitus, and growth failure (height less than the third percentile). Her height was 140 cm, and her BMI was 28.1 (97th percentile). At presentation, she had not yet reached menarche. Physical examination revealed Tanner 2 breast development, acne, hirsutism, moon facies, dorsocervical fat pad, central obesity, and stretch marks. Initial laboratory tests showed hemoglobin A1C of 13%, low-density lipoprotein of 167 mg/dL, triglycerides of 344 mg/dL, high-density lipoprotein of 26 mg/dL, creatinine of 0.4 mg/dL, and elevated liver enzymes. Abdominal ultrasound indicated moderate hepatic steatosis changes.

Given the high suspicion of CS, a hormonal profile was conducted (Table 1), confirming CS and subsequently diagnosing CD. A nuclear MRI revealed a 2.6 × 1.8 mm pituitary lesion (Figure 1), prompting referral for transsphenoidal resection of the pituitary microadenoma.

Laboratories Reference range Initial One month Three months Six months
TSH (mUI/L) 0.35-4.94 2.17 2.01
AM cortisol (µg/dL) 6.02-18.4 17.3 4.06 <0.5 4.7
1 mg DST (µg/dL) <1.8 3.4
8 mg DST (µg/dL) <50% suppression 1.9 (78% suppression)
Urine-free cortisol (µg/24h) <90 235
ACTH (pg/mL) 10-60 83.5 19.2 9.7
IGF-1 (ng/mL) 36-300 293
Table 1: Pertinent laboratory investigation at baseline and follow-up with our patient

ACTH, adrenocorticotropic hormone; DST, dexamethasone suppression test; IGF-1, insulin growth factor-1; TSH, thyroid-stimulating hormone

Axial-view-of-a-T1-MRI-with-contrast-showing-a-sellar-lesion
Figure 1: Axial view of a T1 MRI with contrast showing a sellar lesion

The red arrow shows a microadenoma in relation to the normal pituitary gland.

Approximately one month after the suppression tests and while awaiting surgery, the patient presented to the emergency department with a sudden, severe, holocranial headache accompanied by projectile vomiting and diplopia, suggestive of meningism. A computed axial tomography of the central nervous system was conducted, revealing no structural abnormalities. Symptoms resolved with intravenous analgesia within approximately four to six hours. Subsequently, the patient experienced a significant decrease in insulin requirements, ultimately leading to the suspension of insulin therapy due to persistent hypoglycemia.

Weeks after the headache episode, the patient was reevaluated in the emergency department with a three-day history of diffuse abdominal pain, vomiting, asthenia, myalgia, hypotension, tachycardia, orthostatism, and recurrent hypoglycemia despite insulin suspension. Acute adrenal insufficiency was suspected and confirmed by a cortisol level of 4.06 µg/dL. Treatment with intravenous hydrocortisone 50 mg every six hours was initiated, leading to complete resolution of symptoms within 72 hours. The patient was discharged on maintenance therapy with oral hydrocortisone (20 mg in the morning and 10 mg at night). Subsequent follow-ups showed undetectable cortisol levels. Currently, the patient has been followed up for 10 months post-event, showing persistent clinical and hormonal remission of her disease.

Discussion

CD represents approximately 80% of cases of endogenous hypercortisolism, and pituitary microadenomas are the most common cause of CD in all age groups [5]. CD prevalence is 0.3-6.2 cases per 100,000 people [3], which represents 4.4% of all pituitary adenomas [6], and it is up to five times more likely to occur in women than men. Spontaneous remission of CD is rare, and it is mainly due to the apoplexy of a pituitary tumor [7].

PA is a potentially fatal condition resulting from hemorrhage or necrosis of a pituitary adenoma that produces compression of the surrounding structures with symptoms that can be critical and even fatal [8]. PA affects between 2% and 12% of patients with pituitary adenomas, mainly in nonfunctional macroadenomas [9]. Although the main mechanism of PA is hemorrhage, it can also be due to a hemorrhagic infarction or an infarction without hemorrhage; this last scenario is clinically less aggressive [10]. Among the most important precipitating factors are craniocerebral trauma, pregnancy, thrombocytopenia, coagulopathies, pituitary stimulation tests, drugs such as anticoagulants and estrogens, surgeries that are complicated by hypotension, and radiotherapy [4,11,12].

There are three unique aspects of our case. First, the age of onset is 14 years old. This characteristic has been reported in less than 6% of cases of CD, with a mean age of onset between 12.3 and 14.1 years and a slightly higher incidence in men (63%) [13]. In this population, CD is the most common cause of hypercortisolism, accounting for 75-80% of all cases [14]. Furthermore, our patient presented a significant weight gain, severe compromise in her height, hypertension, depression, and diabetes mellitus, which is compatible with the classic profile described for CD in pediatric ages. It is important to clarify that although type 2 diabetes mellitus is common in adults, it is unusual in the pediatric population [13].

Second, spontaneous remission in CD due to apoplexy has been rarely reported in the past; hence, our case is an important addition to the scant literature on this unusual phenomenon. Although there are characteristics suggestive of PA, such as hyperdense lesions within the pituitary gland and the reinforcing ring, a CT scan has a low sensitivity for detecting pituitary hemorrhage (21-46%); therefore, a negative CT scan does not rule out PA in cases where there is infarction without hemorrhage, a situation that could correspond to our case [15].

The third unique feature of our case is that the stroke occurred in the context of a microadenoma, a situation reported in less than 10 cases in the literature. Despite being a microadenoma, the symptoms of PA were severe, with symptoms of meningism, an intense headache, vomiting, and the development of adrenal insufficiency. Taylor et al. [16] reported a similar case of a 41-year-old female with microadenoma whose PA was associated with severe headache and vomiting.

The main differential diagnosis in our case is cyclical CS (CCS), a disorder that occurs in 15% of CS cases, especially in CD [17]. The diagnosis of CCS is classically established with three peaks and two valleys in cortisol secretion, spontaneous fluctuations, and clinical features of CS [7]. The possibility of CCS was ruled out due to the typical presentation of the PA event and the persistence of hypocortisolism.

Finally, several cases of recurrence of their disease have been described after remission of CS due to AP. Those recurrences usually develop in follow-ups of up to seven years [18]. At the time of the last evaluation (10 months post-PA), the patient remained in remission, but long-term follow-up is required to detect both reactivation and hypopituitarism [19].

Conclusions

CD is a rare entity in the pediatric population, usually associated with a pituitary microadenoma. Spontaneous remission of this disease is very uncommon, but when it occurs, it is mainly due to PA. We describe a case with three unique aspects: CD with an early age of onset of symptoms, spontaneous remission of CD due to PA, which has been rarely reported in the medical literature, and the fact that there are less than 10 clinical case reports of PA associated with microadenoma. It is imperative for clinicians to be aware of this possible outcome in patients with CD.

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From Knee Pain Consultation to Pituitary Surgery: The Challenge of Cushing Disease Diagnosis

Abstract

Cushing syndrome (CS) is a rare endocrinological disorder resulting from chronic exposure to excessive cortisol. The term Cushing disease is used specifically when this is caused by excessive secretion of adrenocorticotropic hormone (ACTH) by a pituitary tumor, usually an adenoma. This disease is associated with a poor prognosis, and if left untreated, it has an estimated 5-year survival rate of 50%. We present the case of a 66-year-old female patient who received a referral to endocrinology for an evaluation of obesity due to right knee arthropathy. Taking into consideration her age, she was screened for osteoporosis, with results that showed diminished bone density. Considering this, combined with other clinical features of the patient, suspicion turned toward hypercortisolism. Laboratory findings suggested that the CS was ACTH-dependent and originated in the pituitary gland. After a second look at the magnetic resonance imaging results, a 4-mm lesion was identified on the pituitary gland, prompting a transsphenoidal resection of the pituitary adenoma.

Introduction

Chronic excessive exposure to glucocorticoids leads to the diverse clinical manifestations of Cushing syndrome (CS), which has an annual incidence ranging from 1.8 to 3.2 cases per million individuals [1]. The syndrome’s signs and symptoms are not pathognomonic, and some of its primary manifestations, such as obesity, hypertension, and glucose metabolism alterations, are prevalent in the general population [2], making diagnosis challenging. Endogenous CS falls into 2 categories: adrenocorticotropic hormone (ACTH)-dependent (80%-85% of cases), mostly due to a pituitary adenoma, or ACTH-independent (15%-20% of cases), typically caused by adrenal adenomas or hyperplasia [3]. Cushing disease (CD) represents a specific form of CS, characterized by the presence of an ACTH-secreting pituitary tumor [1]. Untreated CD is associated with high morbidity and mortality compared to the general population [1], with a 50% survival rate at 5 years [2]. However, surgical removal of a pituitary adenoma can result in complete remission, with mortality rates similar to those of the general population [2]. This article aims to highlight the challenges of suspecting and diagnosing CD and to discuss the current management options for this rare condition.

Case Presentation

A 66-year-old woman received a referral to endocrinology for an evaluation of obesity due to right knee arthropathy. During physical examination, she exhibited a body mass index of 34.3 kg/m2, blood pressure of 180/100, a history of non-insulin-requiring type 2 diabetes mellitus with glycated hemoglobin (HbA1c) of 6.9% (nondiabetic: < 5.7%; prediabetic: 5.7% to 6.4%; diabetic: ≥ 6.5%) and hypertension. Additionally, the patient complained of proximal weakness in all 4 limbs.

Diagnostic Assessment

Upon admission, densitometry revealed osteoporosis with T scores of −2.7 in the lumbar spine and −2.8 in the femoral neck. Hypercortisolism was suspected due to concomitant arterial hypertension, central obesity, muscle weakness, and osteoporosis. Physical examination did not reveal characteristic signs of hypercortisolism, such as skin bruises, flushing, or reddish-purple striae. Late-night salivary cortisol (LNSC) screening yielded a value of 8.98 nmol/L (0.3255 mcg/dL) (reference value [RV] 0.8-2.7 nmol/L [0.029-0.101 mcg/dL]) and ACTH of 38.1 pg/mL (8.4 pmol/L) (RV 2-11 pmol/L [9-52 pg/mL]). A low-dose dexamethasone suppression test (LDDST) was performed (cutoff value 1.8 mcg/dL [49 nmol/L]), with cortisol levels of 7.98 mcg/dL (220 nmol/L) at 24 hours and 20.31 mcg/dL (560 nmol/L) at 48 hours. Subsequently, a high-dose dexamethasone suppression test (HDDST) was conducted using a dose of 2 mg every 6 hours for 2 days, for a total dose of 16 mg, revealing cortisol levels of 0.0220 nmol/L (0.08 ng/mL) at 24 hours and 0.0560 nmol/L (0.0203 ng/mL) at 48 hours, alongside 24-hour urine cortisol of 0.8745 nmol/L (0.317 ng/mL) (RV 30-145 nmol/24 hours [approximately 11-53 μg/24 hours]) [4].

These findings indicated the presence of endogenous ACTH-dependent hypercortisolism of pituitary origin. Consequently, magnetic resonance imaging (MRI) was requested, but the results showed no abnormalities. Considering ectopic ACTH production often occurs in the lung, a high-resolution chest computed tomography scan was performed, revealing no lesions.

Treatment

Upon reassessment, the MRI revealed a 4-mm adenoma, prompting the decision to proceed with transsphenoidal resection of the pituitary adenoma.

Outcome and Follow-Up

The histological analysis revealed positive staining for CAM5.2, chromogranin, synaptophysin, and ACTH, with Ki67 staining at 1%. At the 1-month follow-up assessment, ACTH levels were 3.8 pmol/L (17.2 pg/mL) and morning cortisol was 115.8621 nmol/L (4.2 mcg/dL) (RV 5-25 mcg/dL or 140-690 nmol/L). Somatomedin C was measured at 85 ng/mL (RV 70-267 ng/mL) and prolactin at 3.5 ng/mL (RV 4-25 ng/mL). At the 1-year follow-up, the patient exhibited a satisfactory postoperative recovery. However, she developed diabetes insipidus and secondary hypothyroidism. Arterial hypertension persisted. Recent laboratory results indicated a glycated hemoglobin (HbA1c) level of 5.4%. Medications at the time of follow-up included prednisolone 5 milligrams a day, desmopressin 60 to 120 micrograms every 12 hours, losartan potassium 50 milligrams every 12 hours, and levothyroxine 88 micrograms a day.

Discussion

CD is associated with high mortality, primarily attributable to cardiovascular outcomes and comorbidities such as metabolic and skeletal disorders, infections, and psychiatric disorders [1]. The low incidence of CD in the context of the high prevalence of chronic noncommunicable diseases makes early diagnosis a challenge [2]. This case is relevant for reviewing the diagnostic approach process and highlighting the impact of the availability bias, which tends to prioritize more common diagnoses over rare diseases. Despite the absence of typical symptoms, a timely diagnosis was achieved.

Once exogenous CS is ruled out, laboratory testing must focus on detecting endogenous hypercortisolism to prevent misdiagnosis and inappropriate treatment [5]. Screening methods include 24-hour urinary free cortisol (UFC) for total cortisol load, while circadian rhythm and hypothalamic-pituitary-adrenal (HPA) axis function may be evaluated using midnight serum cortisol and LNSC [5]. An early hallmark of endogenous CS is the disruption of physiological circadian cortisol patterns, characterized by a constant cortisol level throughout the day or no significant decrease [2]. Measuring LNSC has proven to be useful in identifying these patients. The LNSC performed on the patient yielded a high result.

To assess HPA axis suppressibility, tests such as the overnight and the standard 2-day LDDST [5] use dexamethasone, a potent synthetic corticosteroid with high glucocorticoid receptor affinity and prolonged action, with minimal interference with cortisol measurement [6]. In a normal HPA axis, cortisol exerts negative feedback, inhibiting the secretion of corticotropin-releasing-hormone (CRH) and ACTH. Exogenous corticosteroids suppress CRH and ACTH secretion, resulting in decreased synthesis and secretion of cortisol. In pathological hypercortisolism, the HPA axis becomes partially or entirely resistant to feedback inhibition by exogenous steroids [56]. The LDDST involves the administration of 0.5 mg of dexamethasone orally every 6 hours for 2 days, with a total dose of 4 mg. A blood sample is drawn 6 hours after the last administered dose [6]. Following the LDDST, the patient did not demonstrate suppression of endogenous corticosteroid production.

After diagnosing CS, the next step in the diagnostic pathway involves categorizing it as ACTH-independent vs ACTH-dependent. ACTH-independent cases exhibit low or undetectable ACTH levels, pointing to adrenal origin. The underlying principle is that excess ACTH production in CD can be partially or completely suppressed by high doses of dexamethasone, a response not observed in ectopic tumors [6]. In this case, the patient presented with an ACTH of 38.1 pg/mL (8.4 pmol/L), indicative of ACTH-dependent CD.

Traditionally, measuring cortisol levels and conducting pituitary imaging are standard practices for diagnosis. Recent advances propose alternative diagnostic methods such as positron emission tomography (PET) scans and corticotropin-releasing factor (CRF) tests [7]. PET scans, utilizing radioactive tracers, offer a view of metabolic activity in the adrenal glands and pituitary region, aiding in the identification of abnormalities associated with CD. Unfortunately, the availability of the aforementioned tests in the country is limited.

Once ACTH-dependent hypercortisolism is confirmed, identifying the source becomes crucial. A HDDST is instrumental in distinguishing between a pituitary and an ectopic source of ACTH overproduction [26]. The HDDST involves administering 8 mg of dexamethasone either overnight or as a 2-day test. In this case, the patient received 2 mg of dexamethasone orally every 6 hours for 2 days, totaling a dose of 16 mg. Simultaneously, a urine sample for UFC is collected during dexamethasone administration. The HDDST suppressed endogenous cortisol production in the patient, suggesting a pituitary origin.

In ACTH-dependent hypercortisolism, CD is the predominant cause, followed by ectopic ACTH syndrome and, less frequently, an ectopic CRH-secreting tumor [35]. With the pretest probability for pituitary origin exceeding 80%, the next diagnostic step is typically an MRI of the pituitary region. However, the visualization of microadenomas on MRI ranges from 50% to 70%, requiring further testing if results are negative or inconclusive [5]. Initial testing of our patient revealed no pituitary lesions. Following a pituitary location, ACTH-secreting tumors may be found in the lungs. Thus, a high-resolution chest computed tomography scan was performed, which yielded negative findings. Healthcare professionals must keep these detection rates in mind. In instances of high clinical suspicion, repeating or reassessing tests and imaging may be warranted [3], as in our case, ultimately leading to the discovery of a 4-mm pituitary adenoma.

It is fundamental to mention that the Endocrine Society Clinical Practice Guideline on Treatment of CS recommends that, when possible, all patients presenting with ACTH-dependent CS and lacking an evident causal neoplasm should be directed to an experienced center capable of conducting inferior petrosal sinus sampling to differentiate between pituitary and nonpituitary or ectopic cause [8]. However, in this instance, such a referral was regrettably hindered by logistical constraints.

Regarding patient outcomes and monitoring in CD, there is no consensus on defining remission criteria following tumor resection. Prolonged hypercortisolism results in suppression of corticotropes, resulting in low levels of ACTH and cortisol after surgical intervention. Typically, remission is identified by morning serum cortisol values below 5 µg/dL (138 nmol/L) or UFC levels between 28 and 56 nmol/d (10-20 µg/d) within 7 days after surgical intervention. In our case, the patient’s morning serum cortisol was 115.8621 nmol/L (4.2 µg/dL), indicating remission. Remission rates in adults are reported at 73% to 76% in selectively resected microadenomas and at 43% in macroadenomas [8], highlighting the need for regular follow-up visits to detect recurrence.

Following the surgery, the patient experienced diabetes insipidus, a relatively common postoperative occurrence, albeit usually transient [8]. It is recommended to monitor serum sodium levels during the first 5 to 14 days postsurgery for early detection and management. Additionally, pituitary deficiencies may manifest following surgery. In this patient, prolactin levels were compromised, potentially impacting sexual response. However, postoperative somatomedin levels were normal, and gonadotropins were not measured due to the patient’s age group, as no additional clinical decisions were anticipated based on those results. Secondary hypothyroidism was diagnosed postoperatively.

Moving forward, it is important to emphasize certain clinical signs and symptoms for diagnosing CD. The combination of low bone mineral density (Likelihood Ratio [LR] +21.33), central obesity (LR +3.10), and arterial hypertension (LR + 2.29) [9] has a higher positive LR than some symptoms considered “characteristic,” such as reddish-purple striae, plethora, proximal muscle weakness, and unexplained bruising [210]. It is essential to give relevance to the signs the patient may present, emphasizing signs that have been proven to have an increased odds ratio (OR) such as osteoporosis (OR 3.8), myopathies (OR 6.0), metabolic syndrome (OR 2.7) and adrenal adenoma (OR 2.4) [9‐11]. The simultaneous development and worsening of these conditions should raise suspicion for underlying issues. Understanding the evolving nature of CD signs highlights the importance of vigilance during medical examinations, prioritizing the diagnostic focus, and enabling prompt initiation of treatment.

Recognizing the overlap of certain clinical features in CS is fundamental to achieving a timely diagnosis.

Learning Points

  • CS diagnosis is challenging due to the absence of pathognomonic signs and symptoms and the overlap of features present in many pathologies, such as metabolic syndrome.
  • Early detection of CS is crucial, given its association with high morbidity and mortality resulting from chronic exposure to glucocorticoids.
  • Recognizing the combination of low bone mineral density, obesity, hypertension, and diabetes as valuable clinical indicators is key in identifying CS.
  • Interdisciplinary collaboration is essential to achieve a comprehensive diagnostic approach.

Acknowledgments

We extend our gratitude to Pontificia Universidad Javeriana in Bogotá for providing essential resources and facilities that contributed to the successful completion of this case report. Special acknowledgment is reserved for the anonymous reviewers, whose insightful feedback significantly enhanced the quality of this manuscript during the peer-review process. Their contributions are sincerely appreciated.

Contributors

All authors made individual contributions to authorship. A.B.O. was involved in the diagnosis and management of this patient. M.A.G., J.M.H., and A.B.O. were involved in manuscript drafting and editing. All authors reviewed and approved the final draft.

Funding

This research received no public or commercial funding.

Disclosures

The authors declare that they have no conflicts of interest related to the current study.

Informed Patient Consent for Publication

Signed informed consent could not be obtained from the patient or a proxy but has been approved by the treating institution.

Data Availability Statement

Restrictions apply to the availability of some or all data generated or analyzed during this study to preserve patient confidentiality or because they were used under license. The corresponding author will on request detail the restrictions and any conditions under which access to some data may be provided.

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Abbreviations

 

  • ACTH

    adrenocorticotropic hormone

  • CD

    Cushing disease

  • CRH

    corticotropin-releasing hormone

  • CS

    Cushing syndrome

  • HDDST

    high-dose dexamethasone suppression test

  • HPA

    hypothalamic-pituitary-adrenal

  • LDDST

    low-dose dexamethasone suppression test

  • LNSC

    late-night salivary cortisol

  • MRI

    magnetic resonance imaging

  • OR

    odds ratio

  • RV

    reference value

  • UFC

    urinary free cortisol

© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

Obesity-Related Hemodynamic Alterations in Patients with Cushing’s Disease

Abstract

Background: Cushing’s disease (CD) is associated with a specific form of metabolic syndrome that includes visceral obesity, which may affect cardiovascular hemodynamics by stimulating hypercortisolism-related metabolic activity. The purpose of this study was to evaluate the relationship between obesity and the hemodynamic profile of patients with CD.
Methods: This prospective clinical study involved a hemodynamic status assessment of 54 patients newly diagnosed with CD with no significant comorbidities (mean age of 41 years). The assessments included impedance cardiography (ICG) to assess such parameters as stroke index (SI), cardiac index (CI), velocity index (VI), acceleration index (ACI), Heather index (HI), systemic vascular resistance index (SVRI), and total arterial compliance index (TACI) as well as applanation tonometry to assess such parameters as central pulse pressure (CPP) and augmentation index (AI). These assessments were complemented by echocardiography to assess cardiac structure and function.
Results: Compared with CD patients without obesity, individuals with CD and obesity (defined as a body mass index ≥ 30 kg/m2) exhibited significantly lower values of ICG parameters characterizing the pumping function of the heart (VI: 37.0 ± 9.5 vs. 47.2 ± 14.3 × 1*1000−1*s−1, p = 0.006; ACI: 58.7 ± 23.5 vs. 76.0 ± 23.5 × 1/100/s2, p = 0.005; HI: 11.1 ± 3.5 vs. 14.6 ± 5.5 × Ohm/s2, p = 0.01), whereas echocardiography in obese patients showed larger heart chamber sizes and a higher left ventricular mass index. No significant intergroup differences in blood pressure, heart rate, LVEF, GLS, TACI, CPP, or AI were noted.
Conclusions: Hemodynamic changes associated with obesity already occur at an early stage of CD and manifest via significantly lower values of the ICG parameters illustrating the heart’s function as a pump, despite the normal function of the left ventricle in echocardiography.

Graphical Abstract

1. Introduction

Cushing’s disease (CD), caused by a pituitary neuroendocrine tumor, leads to a specific type of metabolic syndrome that includes hypertension, obesity, impaired glucose metabolism, and dyslipidemia [1,2,3]. Chronic hypercortisolemia in patients with CD results in the excessive accumulation of visceral fat due to abnormal adipokine production [4]. Visceral obesity plays an important role in hypercortisolism-induced metabolic abnormalities and increased activity of the renin–angiotensin–aldosterone system activity in patients with CD [1,2,3,4,5]. Visceral obesity in patients with CD not only contributes to metabolic syndrome, but it is also an independent risk factor for cardiovascular disease [1,3,6,7]. Importantly, the structure and function of adipose tissue in patients with CD differ from those of healthy individuals [1,8,9]. The various hypercortisolism-induced metabolic abnormalities occurring in obese patients with CD may affect cardiovascular hemodynamics. There are no data on the effect of obesity on the hemodynamic profile of patients with CD and also few data are known on the association between obesity and hemodynamic disturbances in people without CD [10,11]. It was shown that the hemodynamic profile of a person with obesity is characterized by increased cardiac output and thoracic fluid content and decreased vascular resistance in comparison with these parameters in healthy individuals [12].
More studies are needed to enhance our understanding of the pathophysiology of CD-related obesity as a modifiable cardiovascular risk factor, in order to develop effective preventive and therapeutic strategies. Unfortunately, subclinical consequences of hypercortisolism in newly diagnosed patients with early CD, particularly with comorbid obesity, may be undetectable with standard methods. Therefore, novel and easy-to-use diagnostic methods would be of additive value to the standard methods of assessing cardiovascular structure and function in patients with CD. A detailed evaluation of the nature of obesity in patients with CD by innovative noninvasive diagnostic methods, such as impedance cardiography (ICG), applanation tonometry (AT), and echocardiographic assessment of global longitudinal strain (GLS), may provide additional data on cardiovascular hemodynamics, particularly the heart’s pumping function, preload, and afterload [13,14,15,16,17,18]. Our previous studies demonstrated the usefulness of ICG in identifying subclinical cardiovascular complications in patients with CD [19,20].
The purpose of this analysis was to assess the relationship between obesity and the hemodynamic profile of patients newly diagnosed with CD with no significant comorbidities.

2. Materials and Methods

2.1. Study Population

This was a prospective observational cohort study involving a comprehensive assessment of 54 patients (mean age of 41 years) newly diagnosed with CD with no significant comorbidities (although 64.8% were diagnosed with hypertension). These patients were admitted to the Military Institute of Medicine—National Research Institute between 2016 and 2021 in order to undergo a thorough cardiovascular assessment prior to transsphenoidal pituitary neuroendocrine tumor resection surgery.
This study was approved by the ethics committee at the Military Institute of Medicine—National Research Institute (approval No. 76/WIM/2016) and compliant with the Declaration of Helsinki and Good Clinical Practice guidelines. Each patient received detailed information on the purpose of this study and signed an informed consent form. This study was financed by the Polish Ministry of Research and Higher Education/Military Institute of Medicine—National Research Institute in Warsaw (grant No. 453/WIM).

2.2. Inclusion Criteria

The diagnosis of CD was established based on the presence of the typical (clinical and hormonal) evidence of hypercortisolism with no adrenocorticotropic hormone (ACTH) response to corticotropin-releasing hormone (CRH) stimulation, which meets the current guidelines for the diagnosis and treatment of CD [21,22,23]. Physical examination findings consistent with the signs and symptoms of CD, including central obesity with the characteristic altered body fat distribution (a moon face and a short, thick neck); muscle atrophy in the torso and limbs; purplish stretch marks on the abdomen, hips, and thighs; thinned skin; ecchymoses; signs and symptoms of hyperandrogenism; bone pain; frequent infections; erectile dysfunction in men; and secondary amenorrhea and infertility in women. Hormone test results included elevated 24 h urinary free cortisol levels, increased morning serum cortisol levels, altered circadian rhythmicity of ACTH and cortisol secretion, elevated or detectable morning serum ACTH, and a lack of overnight serum cortisol suppression to <1.8 mg/dL during a low-dose dexamethasone suppression test (1 mg or 2 mg of dexamethasone administered at midnight). In order to ensure a pituitary etiology of CD, all patients underwent a two-day high-dose (2 mg every 6 h = a total of 8 mg) dexamethasone suppression test (HDDST), which was expected to show low serum cortisol or a >50% decrease in urinary-free cortisol levels. Moreover, each patient was shown to have no ACTH secretion response to a CRH stimulation test (with 100 μg intravenous CRH), and the presence of a pituitary neuroendocrine tumor was confirmed via contrast magnetic resonance imaging of the pituitary. Patients with inconclusive hormone tests or imaging studies additionally underwent bilateral inferior petrosal sinus sampling (used to determine ACTH levels in the venous blood before and after CRH stimulation) [21,22,23].

2.3. Exclusion Criteria

The following comorbidities, which might considerably affect hemodynamic profiles, constituted our study exclusion criteria: (1) heart failure with mildly reduced or reduced left ventricular ejection fraction (LVEF) (i.e., LVEF of <50%); (2) cardiomyopathy; (3) clinically significant valvular heart disease or arrhythmia; (4) coronary artery disease, including a history of acute coronary syndrome; (5) a poor acoustic window on echocardiography; (6) a history of pulmonary embolism; (7) a history of a stroke or transient ischemic attack; (8) renal failure (estimated glomerular filtration rate < 60 mL/min/1.73 m2); (9) peripheral vascular disease and polyneuropathy; (10) chronic obstructive pulmonary disease; (11) respiratory failure (decreased partial pressure of arterial oxygen [PaO2] < 60 mmHg and/or increased partial pressure of carbon dioxide [PaCO2] > 45 mmHg); (12) a history of head trauma; (13) pregnancy; (14) age < 18 years; (15) no written informed consent.

2.4. Additional Hormone Tests

Due to the fact that hypercortisolemia inhibits gonadotropin release, hormone testing was expanded to include follicle-stimulating hormone and luteinizing hormone levels. The patients also had their serum thyroid-stimulating hormone levels tested to determine possible hypothyroidism, associated with reduced CRH and thyroid-stimulating hormone secretion and hypercortisolism-induced alterations in thyroid function. The patients with CD included in this study were not receiving any medications affecting the hypothalamus–pituitary–adrenal axis. None of the female patients with CD were pregnant at the time of the study or had given birth within the previous five years.

2.5. Laboratory Tests

In order to detect possible metabolic conditions, such as impaired fasting glucose, type 2 diabetes mellitus, or dyslipidemia, all patients underwent fasting blood tests from venous blood samples collected in the morning (at 6:00 a.m.). The tests evaluated the levels of fasting glucose, creatinine, eGFR, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides, as well as a complete blood count.

2.6. Anamnesis and Physical Examination

The patients were thoroughly evaluated for cardiovascular risk factors, cardiovascular signs and symptoms, a family history of cardiovascular disease, comorbidities, prescription medications and other drugs, and smoking.
The body mass index (BMI) was calculated, and obesity was determined based on the International Diabetes Federation and European Society of Cardiology guidelines, which define it as a BMI of ≥30 kg/m2 [24,25]. In the study, patients were divided into two groups: patients with CD and obesity (defined as high body mass index ≥ 30 kg/m2) and patients with CD without obesity (defined as normal BMI < 30 kg/m2).
Physical examination included the resting heart rate (HR), systolic and diastolic blood pressure, and anthropometric parameters.
Office blood pressure measurements were taken by a trained nurse in seated patients in the morning, after a 5 min rest. The blood pressure monitor used was Omron M4 Plus (Omron Healthcare Co. Ltd., Kyoto, Japan), which meets the European Society of Cardiology criteria [26].

2.7. Echocardiography

Two-dimensional echocardiography included standard parasternal, apical, and subcostal views with a 2.5 MHz transducer (VIVID E95, GE Medical System, Wauwatosa, WI, USA) in accordance with the American Society of Echocardiography (ASE) and the European Association of Cardiovascular Imaging (EACVI) guidelines [27]. The parasternal long-axis view was used to measure the left ventricular end-diastolic diameter (LVEDd), right ventricular end-diastolic diameter (RVEDd), interventricular septal thickness, and left atrial (LA) diameter. Linear 2-dimensional left ventricular measurements were used to calculate the left ventricular mass index (LVMI), which is the left ventricular mass divided by the body surface area (LVMI cut-off values of >115 g/m2 for men and >95 g/m2 for women meet ASE and EACVI criteria for the diagnosis of left ventricular hypertrophy). The LVEF was calculated with the biplane Simpson method, based on 2-dimensional views of the left ventricle during systole and diastole in four- and two-chamber apical views. The ascending aortic diameter, valvular structure and function, and pericardium were assessed. The patients were assessed for left ventricular diastolic dysfunction according to current guidelines. Pulse wave Doppler in an apical four-chamber view aligned with mitral valve tips was used to visualize mitral inflow, including the early passive blood inflow (E) and the later atrial (A) contribution to the mitral inflow, E/A ratio, and early mitral inflow deceleration time. Apical four-chamber views were used to determine the septal and lateral early diastolic mitral annular velocities (e′ avg), and the E/e′ avg ratio was calculated [27,28].
Global longitudinal strain (GLS) was assessed via electrocardiography-gated automated function imaging in two-, three-, and four-chamber views. The rates of >60 frames per second were used for optimal speckle-tracking strain assessment. Patients with a poor acoustic window were excluded from the study. Semiautomated endocardial border detection was initiated by manually selecting two points identifying the mitral annulus and one point at the apex. Segmental and whole-chamber strain was assessed. The results have been presented in the form of a “bull’s eye” graph. The data were analyzed for four-, three-, and two-chamber views, and average GLS was calculated [29].

2.8. Impedance Cardiography

Based on the phenomenon of impedance variability in individual body segments associated with regional arterial blood flow, ICG is a noninvasive tool for assessing cardiovascular hemodynamics. ICG assessments were conducted by a trained nurse with a Niccomo device (Medis, Ilmenau, Germany) in patients who had been resting for 10 min in a supine position. ICG data were recorded during a 10 min assessment and processed with dedicated software (Niccomo Software, Medis). We analyzed the mean values of the following hemodynamic parameters reflecting the pumping function of the heart: (1) stroke volume (SV [mL]) and stroke index (SI [mL/m2]), based on the following formula: SV = VEPT × (dZmax/Z0) × LVET, where VEPT is tissue volume calculated from body weight, height, and patient sex, Z0 is the initial thoracic impedance, dZmax is the maximum change in thoracic impedance, and LVET is the left ventricular ejection time; (2) cardiac output (CO [mL] = SV × HR), and cardiac index (CI [mL*m−2*min−1]); (3) velocity index (VI [1*1000−1*s−1]); (4) acceleration index (ACI [1/100/s2], which is the peak acceleration of blood flow in the aorta; and (5) Heather index (HI [Ohm/s2] = dZmax × TRC, where TRC the time interval between the R-peak in the electrocardiogram and the C-point on the impedance wave). We also conducted a detailed analysis of the following afterload parameters: (1) systemic vascular resistance (SVR [dyn*s*cm−5]) together with SVR index (SVRI [dyn*s*cm−5*m2]) and (2) total arterial compliance (TAC) and TAC index (TACI [mL/mmHg] = SV/pulse pressure [mL/mmHg*m2]). Preload was assessed based on thoracic fluid content (TFC [1/kOhm], based on the formula TFC = 1000/Z0, where Z0 is the initial thoracic impedance [30,31,32].

2.9. Applanation Tonometry

Applanation tonometry is a novel method of indirectly illustrating arterial pressure waveform in the aorta and arterial stiffness, which reflect left ventricular afterload. AT parameters were assessed noninvasively with a SphygmoCor system (AtCor Medical, Sydney, NSW, Australia). The measurements were taken in supine patients by a qualified nurse immediately after ICG. Radial artery pressure curves were recorded via AT with a micromanometer (Millar Instruments, Houston, TX, USA) strapped onto the left wrist. We selected high-quality recordings for our analysis. Radial pulse was calibrated against the latest brachial systolic and diastolic blood pressure measurement with an oscillometric module of the Niccomo device. SphygmoCor software (version 9.0; AtCor Medical Inc. Pty Ltd., Sydney, NSW, Australia) was used to process the arterial waveform and generate an appropriate aortic blood pressure curve from the radial pulse curve. The analyzed waveforms were composed of the pulse wave generated by the aorta and were augmented by an overlapping reflected wave. Our analyses yielded the following parameters: central systolic blood pressure; central diastolic blood pressure; central pulse pressure (CPP); augmentation pressure, which is the absolute increase in aortic systolic pressure (directly generated by left ventricular contraction) resulting from the reflection wave; and the augmentation index, calculated as AP × 100/CPP, which is a quotient of the augmentation pressure and the blood pressure in the aorta [33].

2.10. Statistical Analysis

For the statistical analysis of the results, we used MS Office Excel 2023 and Statistica 12.0 (StatSof Inc., Tulsa, OK, USA). Data distribution and normality were assessed visually on histograms and with the use of the Kolmogorov–Smirnov test. Continuous variables were expressed as mean ± standard deviation (SD) or median (interquartile range, IQR), and categorical variables were expressed as absolute and relative (percentage) values. In order to evaluate differences between the subgroups of CD patients with and without comorbid obesity, we used Student’s t-test for normally distributed data, and the Mann–Whitney U test for non-normally distributed data. A comparative analysis with the use of the Mann–Whitney U test was conducted on the data from patients stratified into two subgroups: patients with CD and obesity (BMI ≥ 30 kg/m2, n = 22) and patients with CD without obesity (BMI < 30 kg/m2, n = 32). The relationship between selected indices of cardiovascular function and obesity (represented as BMI) was analyzed separately for each one in a multivariable regression model, adjusting for age and hypertension as potential covariates related to hemodynamics. The threshold of statistical significance was adopted at p < 0.05.

3. Results

3.1. Baseline Characteristics

Nearly half of the patients with CD were found to be obese (n = 22, 40.7%). Overall, 20 of the 54 patients with Cushing’s disease (37%) were diagnosed with type 2 diabetes mellitus, 5 (9.3%) had prediabetes, and 29 (46.3%) had normal glucose tolerance. Of the patients with Cushing’s disease and type 2 diabetes, 14 received metformin, 5 received metformin with insulin, and 1 received insulin.
The mean age, HR, hemoglobin, creatinine, and sex distribution were similar in the subgroup with and without obesity (Table 1).
Table 1. Clinical, echocardiographic, hemodynamic, and applanation tonometry variables in patients with Cushing’s disease (CD) and with or without obesity.

3.2. Echocardiographic Assessment

Patients with CD and obesity (BMI ≥ 30 kg/m2) showed larger dimensions of heart chambers and ascending aorta (RVEDd, p < 0.001; LVEDd, p = 0.028; LA diameter, p < 0.001; aortic arch, p = 0.005) and higher rates of left ventricular mass index (LVMI, p = 0.028). We observed no significant differences between the subgroups in terms of the systolic (LVEF or GLS) or diastolic function of the left ventricle (Table 1).

3.3. ICG and AT Assessment

The most noticeable differences in ICG were observed for parameters of the left ventricular function as a pump. In obese individuals, VI (p = 0.006), ACI (p = 0.005), and HI (p = 0.012) were lower, whereas the systolic time ratio (STR) was higher (p = 0.038) than those in non-obese individuals, with SI and CI comparable in both subgroups. We observed no significant differences in afterload (TACI, SVRI, CPP, or augmentation index) or preload (TFC) parameters (Table 1).

3.4. Correlation Analysis

Analyzing the relationships between BMI and ICG hemodynamic parameters, we observed significant correlations, independent of sex and hypertension, between BMI and CI (R = 0.46; p < 0.001), SI (R = 0.29; p = 0.043), SVRI (−0.31; 0.028), and VI (R = −0.37; p = 0.0006)—see Table 2.
Table 2. Correlations between hemodynamic parameters assessed with impedance cardiography and body mass index, adjusted for sex and hypertension in multivariable regression models.

4. Discussion

The results of our study revealed a relationship between obesity and hemodynamic profile assessed via ICG in patients newly diagnosed with active CD. The use of novel diagnostic modalities demonstrated that excessive fat accumulation in young and middle-aged patients with CD, already at the early stages of the disease, is associated with some hemodynamic changes in the cardiovascular system, which—at that stage—may still be undetectable in routine assessments. These findings support the need for the early detection of subclinical heart dysfunction in patients with CD to enable early treatment and help prevent cardiovascular complications [1,34,35,36].
Occurring in 25%–100% of patients with CD, visceral obesity is one of the most common components of metabolic syndrome, often being the first sign of the disease. The duration of hypercortisolism correlates with obesity development [1,7,37,38], with chronic excessive cortisol levels being responsible for the abnormal distribution of adipose tissue [39]. The mechanisms behind this phenomenon may be due to the tissue overexpression of the 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which affects the pattern of excessive fat distribution in the torso, face, and neck [1,6]. Visceral obesity found in patients with CD is not only a component of metabolic syndrome but is in itself associated with increased metabolic activity, which makes it an independent cardiovascular risk factor, leading to the development of cardiovascular disease [1,4,9]. The tendency to accumulate visceral fat in patients with CD is also associated with abnormal adipokine production [4,6,40,41].
Our study included patients newly diagnosed with active CD with no clinically significant cardiovascular disease. Males were underrepresented in both subgroups. The proportion of patients with hypertension was 64.8%, which is comparable with that reported by other authors [38,42,43,44] and similarly distributed between subgroups. However, the patients in our study presented well-controlled hypertension (mean blood pressure was 126/83 mmHg), usually with one or two medications. Considering both sex and hypertension as potential confounders, these variables were included in regression models evaluating correlations between hemodynamics and BMI.
Similar to reports by other authors, our study showed higher SV and CO values in obese patients with CD; however, the respective indexed values (SI and CI) were comparable in obese and non-obese patients [12,45]. A more detailed ICG assessment demonstrated significant impairment of the pumping function of the heart as evidenced by lower HI, VI, and ACI values, and a higher STR value. The analysis of correlations revealed the independence of age and sex interrelation between some hemodynamic indices (CI, SI, SVRI, VI) and BMI. The paradox of the positive relation of obesity with volume indices of left ventricular function (CI and SI), which is negative with the marker of both its outflow and myocardial contractility (VI) encourages further studies investigating the (patho)physiological background of this phenomenon.
These findings were detected despite the lack of echocardiographic evidence of left ventricular systolic or diastolic dysfunction.
Moreover, our study showed larger heart chamber diameters and significantly higher LVMI in patients with CD and obesity, which is consistent with numerous earlier reports by other authors [46,47,48]. Nonetheless, it seems that in this case, increased heart chamber size and left ventricular hypertrophy should not be considered as only secondary to an increase in body weight. Hypercortisolism in patients with CD worsens the structural and functional condition of the heart muscle and may lead to myocardial fibrosis [48]. This results in myocardial remodeling associated with concentric left ventricular hypertrophy, which may impair left ventricular hemodynamic function, subsequently leading to myocardial dysfunction and symptomatic heart failure [49,50,51]. The effective treatment of patients with CD has been shown to normalize their serum cortisol levels and ultimately stop myocardial remodeling [47]. Therefore, the ICG-evidenced impaired pumping function of the heart may result from myocardial remodeling associated with complex metabolic and neuroendocrine changes in obese patients with CD [52]. These findings are consistent with previous reports on the adverse effect of obesity on left ventricular contractility [53,54,55,56].
The potential mechanisms underlying the results of our study remain to be elucidated. An interesting perspective is represented by the cross-talk between glucocorticoid (GR) and mineralocorticoid receptors (MR) and their impact on metabolic syndrome. Excessive activation of the MR in extra-renal tissues by aldosterone or glucocorticoids depending on the expression of 11beta-hydroxysteroid dehydrogenase type 2 has been shown to be associated with the development of vascular dysfunction and metabolic abnormalities, leading to obesity and metabolic syndrome. High concentrations of aldosterone may also activate the transcriptional function of the GR. These mechanisms result in an interaction between GR and MR in the regulation of adipogenesis [57].
The novelty of our approach is due to the use of noninvasive tools (ICG, AT) for hemodynamic assessment of the cardiovascular system in patients with CD to detect subclinical changes associated with obesity. On the one hand, our findings support earlier observations in other patient groups; on the other hand, they cast a new light on the relationship between obesity and an impaired hemodynamic profile in CD, which may result in the early development of cardiovascular complications.

4.1. Clinical Implications

We determined that a dysfunctional pumping action of the heart is the key marker of impaired cardiovascular hemodynamics in obese patients newly diagnosed with CD. The use of noninvasive diagnostic methods in this study revealed a complex relationship between obesity-related hemodynamic changes and the efficiency of left ventricular contractions. An early assessment of a patient’s hemodynamic profile may help detect subclinical cardiovascular dysfunction. Such a personalized approach may facilitate early therapeutic intervention and monitoring of treatment effectiveness focused on preventing myocardial remodeling and heart dysfunction.

4.2. Limitations

One limitation of our study was the small sample size. This was a result of the relatively low incidence of pituitary neuroendocrine tumors secreting ACTH. The exclusion of patients with clinically significant comorbidities further diminished the study population. However, this helped to eliminate the effect of additional factors on hemodynamic profiles. The patients assessed in our study were mostly young and middle-aged individuals with CD; therefore, our conclusions should not be extrapolated to older subjects. Although we conducted neither cardiac stress tests nor coronary angiography to exclude asymptomatic ischemic heart disease, other thorough assessments showed no physical, electrocardiographic, or echocardiographic evidence suggesting myocardial ischemia. Another potential limitation of our study is the fact that some patients had hypertension; however, it was well controlled with medications. The hemodynamic assessments involved the use of noninvasive methods as an alternative to the more expensive and less readily available invasive techniques. Nonetheless, we acknowledge the fact that noninvasive measurements can only provide indirect measurements and depend on the patient’s condition, which may vary over time.

5. Conclusions

The results of our study support the usefulness of ICG in diagnosing early heart dysfunction associated with obesity in patients with CD. Asymptomatic impairment of the heart’s pumping function seems to be the earliest clinical sign of cardiovascular hemodynamic abnormalities, which at this stage are still undetectable with standard echocardiography. Individual hemodynamic profile assessment with novel noninvasive diagnostic methods encourages further studies on cardiovascular system function in obese individuals with CD and on the use of personalized therapies, which aim at preventing adverse cardiovascular events.

Author Contributions

Conceptualization, A.J. and P.K.; methodology, A.J., P.K., G.G., B.U.-Ż., P.W. and G.Z.; software, P.K.; validation, A.J., P.K., B.U.-Ż., P.W. and G.Z.; formal analysis, P.K., P.W., G.G. and G.Z.; investigation, A.J., P.K., B.U.-Ż., P.W. and G.Z.; resources, A.J., P.K., B.U.-Ż., P.W. and G.Z.; data curation, A.J., P.K., B.U.-Ż., P.W., G.Z., A.K., R.W. and M.B.; writing—original draft preparation, A.J. and P.K.; writing—review and editing, G.G., B.U.-Ż., P.W. and G.Z.; visualization, A.J.; supervision, G.G. and G.Z.; project administration, G.Z.; funding acquisition, G.Z. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Polish Ministry of Research and Higher Education/Military Institute of Medicine—National Research Institute in Warsaw (grant No. 453/WIM).

Institutional Review Board Statement

The study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines and approved by the Bioethics Committee at the Military Institute of Medicine—National Research Institute in Warsaw, Poland (approval No. 76/WIM/2016; 21 December 2016).

Informed Consent Statement

Informed consent was obtained from all subjects involved in the study.

Data Availability Statement

The data presented in this study are available upon request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

Acknowledgments

We would like to thank the medical personnel of the Military Institute of Medicine—National Research Institute in Warsaw for the provided patient care.

Conflicts of Interest

The authors declare no conflicts of interest.

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Hiding In Plain Sight: Florid Cushing’s Disease Presenting As A Severe Extremity Cellulitis

Abstract

Disclosure: C.M. Godar: None. E.B. Noble: None. N.O. Vietor: None. T.S. Knee: None.

Background: Cushing’s syndrome may rarely present as an emergency known as Florid Cushing’s Syndrome. Patients can exhibit severe hyperglycemia, hypertension, hypokalemia, infections, and hypercoagulability. Cushing’s syndrome is a rare disease, and the constellation of clinical features can be overlooked if clinicians are not aware of the manifestations of hypercortisolism. We present the case of a patient with Cushing’s syndrome that went unrecognized with life-threatening sequelae.

Case presentation: A 52-year-old woman with well-controlled type 2 diabetes and hypertension was admitted to the hospital for severe left lower extremity cellulitis. Prior to hospitalization she had noted rapid weight gain, fatigue, weakness, mental clouding, and moodiness. She was admitted for antibiotics and surgical debridement. The infection persisted despite broad spectrum antibiotics, multiple surgical debridements, and skin grafting. She became bacteremic, and extremity amputation was considered. She additionally developed hypertensive emergency, refractory hypokalemia, and hyperglycemia to 396 mg/dL. Exam was notable for facial plethora, supraclavicular fullness, dorsocervical fat pad, and violaceous abdominal striae. Cushing’s Syndrome was suspected, and labs revealed a significantly elevated random serum cortisol of 60.5mcg/dL (Ref 6.2-19.4), significantly elevated 24H urine cortisol of 2157mcg/24H (Ref 0-50), and ACTH elevated to 81.8pg/mL (Ref 7.2-63.3) that confirmed Cushing’s Disease. MRI sella and octreotide scans did not localize a lesion. Inpatient therapy included multiple antihypertensive agents, insulin drip, aggressive potassium repletion, and initiation of ketoconazole to reduce cortisol levels. Ketoconazole was maximally dosed and she underwent surgical exploration and removal of a small pituitary microadenoma. Following surgery, she developed transient adrenal insufficiency requiring hydrocortisone and she no longer required antihypertensives, insulin, or potassium therapy. Follow up 7 years later has revealed no recurrence of Cushing’s Disease.

Discussion: Cushing’s Syndrome may present with a variety of clinical features and rarely may present as a medical emergency. Delay in diagnosis can lead to Florid Cushing’s Syndrome which carries high risk for morbidity and mortality. This case illustrates the need for clinician awareness of the features of Cushing’s Syndrome: hypertension, hyperglycemia, rapid weight gain, cushingoid exam features, hypokalemia, hirsutism, virilization, infection, and/or hypercoagulable state. Severe hypercortisolism was responsible for this patient’s refractory infection, and if not controlled, she likely would have endured a lower extremity amputation. Rapid detection with elevated random serum and/or urine cortisol and treatment with a cortisol-lowering agent is critical and lifesaving.

Presentation: Thursday, June 15, 2023

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Medium and Long-Term Data from a Series of 96 Endoscopic Transsphenoidal Surgeries for Cushing Disease

Objective

Postoperative data on Cushing’s disease (CD) are equivocal in the literature. These discrepancies may be attributed to different series with different criteria for remission and variable follow-up durations. Additional data from experienced centers may address these discrepancies. In this study, we present the results obtained from 96 endoscopic transsphenoidal surgeries (ETSSs) for CD conducted in a well-experienced center.

Methods

Pre- and postoperative data of 96 ETSS in 87 patients with CD were included. All cases were handled by the same neurosurgical team between 2014 and 2022. We obtained data on remission status 3−6 months postoperatively (medium-term) and during the latest follow-up (long-term). Additionally, magnetic resonance imaging (MRI) and pathology results were obtained for each case.

Results

The mean follow-up duration was 39.5±3.2 months. Medium and long-term remission rates were 77% and 82%, respectively. When only first-time operations were considered, the medium- and long-term remission rates were 78% and 82%, respectively. The recurrence rate in this series was 2.5%. Patients who showed remission between 3−6 months had higher longterm remission rates than did those without initial remission. Tumors >2 cm and extended tumor invasion of the cavernous sinus (Knosp 4) were associated with lower postoperative remission rates.

Conclusion

Adenoma size and the presence/absence of cavernous sinus invasion on preopera-tive MRI may predict long-term postoperative remission. A tumor size of 2 cm may be a supporting criterion for predicting remission in Knosp 4 tumors. Further studies with larger patient populations are necessary to support this finding.

Key WordsComplete remission · Neuroendoscopy · Pituitary-dependant Cushing syndrome · Treatment outcome.

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INTRODUCTION

Cushing’s disease (CD) is characterized by excessive secretion of adrenocorticotropic hormone (ACTH) by a corticotropic adenoma in the pituitary gland. In patients with CD whose hypercortisolism is inadequately corrected, morbidity and mortality can increase by up to 4.8 times due to Cushingrelated complications such as osteoporosis, hypertension, dyslipidemia, insulin resistance, and hypercoagulability [11,18].
Endoscopic transsphenoidal surgery (ETSS), the first-line treatment for CD [7], is performed to decrease complications while achieving remission and long-term disease control. Previous studies on CD have reported varying remission rates between 45% and 95% and recurrence rates ranging from 3−66% [2,4,9,16,21,30]. This wide range of differences can be primarily attributed to differences in surgical experience among centers: centers with higher surgical experience have fewer postoperative complications and higher remission rates [4,6]. However, despite initial remission, patients with CD may eventually experience recurrence. The mean recurrence rate at the 5-10-year follow-up is 23% for microadenomas and 33% for macroadenomas [19,23,30].
Since the postoperative rates in the literature are variable, additional data from experienced centers may be necessary to resolve these discrepancies. In this study, we present the medium- and long-term follow-up data from 96 operations for CD that were conducted in a center with a high level of experience for ETSS.
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MATERIALS AND METHODS

The study was conducted in accordance with the Declaration of Helsinki (as revised in 2013). The study was approved by the Ethics Committee of Basaksehir Cam and Sakura City Hospital (No. 2022185). Informed consent was obtained from all patients. The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
This retrospective study included pre and postoperative data of 96 ETSS performed in 87 patients with CD (Fig. 1). CD was diagnosed based on unsuppressed cortisol levels (>1.8 µg/dL) following the 1-mg dexamethasone suppression test, high levels of urinary free cortisol, or late night salivary cortisol and plasma ACTH levels >20 pg/mL [28]. Between 2014 and 2022, all surgeries were conducted by the experienced neurosurgical team (Ö.G., O.T., B.E., E.A.) responsible for endoscopic transsphenoidal procedures at the Pituitary Research Center. The surgeries were performed under perioperative glucocorticoid coverage.

jkns-2023-0100f1.jpg
Fig. 1.
Number of operations and patients included in the study.

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Size, cavernous sinus invasion, sellar and suprasellar infiltration of adenoma on preoperative magnetic resonance imaging (MRI) scans, residual tumor on postoperative MRI scans, postoperative complications, pathology results, remission and recurrence status, and additional postoperative management were evaluated in addition to patients’ demographic data. For follow-up assessments, data obtained 3−6 months postoperatively and during the latest follow-up were included. Three different classifications obtained during radiologic evaluation using MRI were used for pituitary adenomas : 1) maximum size of tumor (MST) : 0−5 mm (group 1), 6−10 mm (group 2), 11−20 mm (group 3), and >20 mm (group 4); 2) Knosp classification : for evaluation of cavernous sinus invasion [22]; and 3) modified Hardy classification : for evaluation of sellar and suprasellar infiltrations [20,39].
In cases of CD without a lesion or with a lesion <6 mm on MRI, confirmation of the central origin and lateralization was provided by inferior petrosal sinus sampling (IPSS) with corticotropin-releasing hormone stimulation [25,26,29]. Under neuronavigation guidance, pure ETSS surgical interventions were performed for all patients by a single surgical team using the Medtronic StealthStation S7 and S8 systems (Medtronic, Minneapolis, MN, USA) together with 4-mm 0°, 30°, and 45° rigid optical instruments and an endoscope. A nasal decongestant spray was administered 1 hour before the operation. The sphenoid ostium was detected from both nostrils, and a bi-nostril approach was used by resecting the posterior nasal septum. After sphenoidectomy, the standard sellar approach was used for lesions in the sellar region. The details of these surgical procedures are described in previous study [14]. Selective adenectomy with ETSS was performed for preoperatively localized and visible tumors, whereas hemihypophysectomy was performed for non-lesional cases. In cases with cavernous sinus-invading tumors, particularly Knops 3-4, the defect which was created by the tumor on the medial wall of anterior cavernous sinus was identified and, it was expanded for resection of the tumor tissue within the cavernous sinus. If a defect was not visible, blunt-ended hook-shaped dissectors were used to create a defect on the medial wall, allowing access for the tumor to enter the cavernous sinus. Hematoxylin and Eosin (H&E) and immunohistochemistry staining were performed for the specimens obtained during ETSS. Adenomas showing positive immunohistological staining for ACTH were diagnosed histologically as corticotropinomas.
CD was considered to be in remission when the cases showed basal cortisol levels <5 µg/dL or suppressed cortisol levels (≤1.8 µg/dL) following the 1-mg dexamethasone suppression test, 3-6 months postoperation, and during the latest follow-up. The study protocol was approved by the ethics committee of our institution.
Data were statistically analyzed using the SPSS 15.0 package (IBM Corp., Armonk, NY, USA). The chi-square test was used for categorical variables. Sample distribution was evaluated with the Kolmogorov-Smirnov test. Continuous independent variables with a normal distribution were compared using the Student’s t-test. Continuous variables with non-normal distributions were compared using the Mann-Whitney U test. p<0.05 was considered statistically significant. A Kaplan-Meier survival analysis was conducted to determine probability and time to recurrence in cases with initial remission.
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RESULTS

Demographic data

A total of 96 ETSS were performed for 87 patients with CD. Of the 87 patients, 68 (79%) were female, and 19 (21%) were male. The mean patient age was 42.2±12.9 years, and the mean duration of follow-up was 39.5±3.2 months. Of the 96 surgeries, 79 (82%) were performed for the first time, six (6%) were performed for residual tumors, and 11 (12%) were performed following a recurrence of the disease. Eight of the 17 patients who underwent reoperations had undergone their first operation at another center.

Preoperative imaging

Table 1 shows the maximum tumor size on preoperative pituitary MRI before each surgical procedure. Preoperative IPSS for lateralization was performed in 42 operations (44%), all of which were first-time cases. Knosp classification based on preoperative pituitary MRI and the modified Hardy classification is presented in Table 1.

Table 1.

Preoperative pituitary magnetic resonance imaging scans

Number of tumors (n=96)
Maximum tumor size
 Group 1, 0−5 mm 41 (42.7)
 Group 2, 6−10 mm 24 (25.0)
 Group 3, 11−20 mm 20 (20.8)
 Group 4, >20 mm 11 (11.5)
Knosp classification
 Grade 0 52 (54.2)
 Grade 1 22 (22.9)
 Grade 2 6 (6.3)
 Grade 3 8 (8.3)
 Grade 4 8 (8.3)
Modified Hardy classification
 0
  A 41 (42.8)
  B
  C
  D
  E
 1
  A 14 (14.6)
  B
  C
  D
  E 4 (4.2)
 2
  A 5 (5.2)
  B
  C
  D
  E 5 (5.2)
 3
  A 1 (1.0)
  B 2 (2.1)
  C
  D
  E 1 (1.0)
 4
  A 1 (1.0)
  B
  C
  D 1 (1.0)
  E 3 (3.1)
 NA 18 (18.8)

Values are presented as number (%). Invasion : 0, sella normal; 1, sella focally expanded and tumor ≤10 mm; 2, sella enlarged and tumor ≥10 mm; 3, localized perforation of the sellar floor; 4, diffuse destruction of the sellar floor. Suprasellar extension : A, no suprasellar extension; B, anterior recesses of the third ventricle obliterated; C, floor of the third ventricle grossly displaced with parasellar extension; D, intracranial (intradural) : anterior, middle or middle fossa; E, into/beneath the cavernous sinus (extradural).

NA : not available

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Postoperative results

Remission was achieved between the 3rd and 6th months in 74 (77%) of the 96 operations, and long-term remission in 79 operations (82%). Among all 96 operations, eight (8%) concluded with a residual tumor. Regarding only first-time operations, five (6%) of the 79 concluded with a postoperative residual tumor. Of the 79 first-time operations, there were 62 cases (78%) of remission between 3 and 6 months. Two (2.5%) of these 79 operations involved recurrence during follow-up, while 60 (97%) showed sustained remission. Those with sustained remission had a median disease-free survival time of 31 months (interquartile range, 14-64) during long-term followup, two cases with recurrence had their recurrence 49 and 54 months after their operation. Survival analysis of cases with remisson and recurrence is presented in Fig. 2. CD persisted after 17 (21.5%) of the 79 first operations.

jkns-2023-0100f2.jpg
Fig. 2.
Survival analysis after the first operation in cases with remission at 3-6 months. Dashed line represents cases with recurrence and, straight line represents cases with sustained remission during long-term follow-up.

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Ten (13%) of the 79 cases underwent reoperation; two were due to recurrence, and eight due to disease persistence. In five cases (29%), the patients were initially unresponsive but showed remission later during the long-term follow-up. Remission was achieved with stereotactic radiosurgery (STRS) and medical treatment in one of these cases, with only STRS in two and only medical treatment in two cases. At the latest follow-up visit, the total number of cases showing remission after the first operation was 65 (82%). Additional details regarding the results of the first operations are provided in Fig. 3.

jkns-2023-0100f3.jpg
Fig. 3.
Results of the cases who had operation for the first time.

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Of the 18 reoperations, the results for one case were excluded since the patient was operated at another center. After the reoperation (n=17), the medium and long-term remission rates were 71% (n=12) and 77% (n=13), respectively. The 3-6-month remission rate did not differ significantly between first-time and reoperations (p=0.5). Residual tumors were present in three cases (18%) after reoperation. Of the early non-responders, one case showed remission after STRS, and none of the responders showed recurrence during long-term follow-up. Additional details regarding the results of reoperations are provided in Fig. 4.

jkns-2023-0100f4.jpg
Fig. 4.
Results of the reoperations in our center.

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Remission rates based on tumor size are presented in Table 2. The initial remission rates of the tumors in MST group 4 were significantly lower than those in the other MST groups (MST 1 vs. 4, p=0.01; MST 2 vs. 4, p=0.001; and MST 3 vs. 4, p=0.006). Comparisons of the other MST groups showed no significant differences. When adenomas were stratified using the 10-mm cut-off, the remission rates did not differ significantly (remission rate, 81% for adenomas <10 mm and 68% for adenomas ≥10 mm; p=0.2). Postoperative residual tumors were observed in five of the 11 tumors (46%) >2 cm (MST group 4) and in one tumor in each of MST groups 1-3 (2%, 4%, and 5%, respectively, p<0.001). Reoperation rate was 17% (n=7) for adenomas ≤5 mm, 18% (n=10) for adenomas ≥6 mm (p=0.9), and 27% (n=3) for adenomas >20 mm (among all grades, p=0.3).

Table 2.

Comparison of remission rates in preoperative pituitary magnetic resonance imaging scans

3−6-month remission Long-term remission
Maximum tumor size
 Group 1, 0−5 mm (n=41) 31 (75.6) 33 (80.5)
 Group 2, 6−10 mm (n=24) 22 (91.7) 22 (91.7)
 Group 3, 10−20 mm (n=20) 17 (85.0) 17 (85.0)
 Group 4, >20 mm (n=11) 4 (36.4) 7 (63.6)
p-value 0.003* 0.200
Knops classification
 0 (n=52) 41 (78.8) 44 (84.6)
 1 (n=22) 21 (95.5) 21 (95.5)
 2 (n=6) 4 (66.7) 3 (50.0)
 3 (n=8) 7 (87.5) 7 (87.5)
 4 (n=8) 1 (12.5) 4 (50.0)
p-value <0.001* 0.010*
Modified Hardy classification
 0
  A (n=41) 32 (78.0) 34 (82.9)
 1
  A (n=14) 12 (85.7) 12 (85.7)
 2
  E (n=4) 3 (75.0) 3 (75.0)
  A (n=5) 5 (100.0) 5 (100.0)
 3
  E (n=5) 2 (40.0) 2 (40.0)
  A (n=1) 1 (100.0) 1 (100.0)
  B (n=2) 2 (100.0) 2 (100.0)
 4
  E (n=1) 0 (0.0) 0 (0.0)
  A (n=1) 1 (100.0) 1 (100.0)
  D (n=1) 0 (0.0) 0 (0.0)
  E (n=3) 1 (33.3) 3 (100.0)
p-value 0.10 0.06
Pathology result
 Corticotropinoma (+) (n=71) 58 (81.7) 60 (84.5)
 Corticotropinoma (-) (n=25) 16 (64.0) 19 (76.0)
p-value 0.07 0.30

Values are presented as number (%). Invasion : 0, sella normal; 1, sella focally expanded and tumor ≤10 mm; 2, sella enlarged and tumor ≥10 mm; 3, localized perforation of the sellar floor; 4, diffuse destruction of the sellar floor. Suprasellar extension : A, no suprasellar extension; B, anterior recesses of the third ventricle obliterated; D, intracranial (intradural) with anterior, middle, or middle fossa; E, into/beneath the cavernous sinus (extradural).

* Statistically significant p-value

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Remission rates based on Knosp and Hardy classifications are presented in Table 2, respectively. The medium-term remission rates in Knosp group 4 were significantly lower than the rates in the other groups (Knosp 0 vs. 4, p<0.001; Knosp 1 vs. 4, p<0.001; Knosp 2 vs. 4, p=0.04; and Knosp 3 vs. 4, p=0.003). Additionally, the medium-term remission rate of tumors in Knosp group 2 was lower than that in Knosp group 1 (p=0.04). However, remission rates did not differ significantly among the other groups. Comparing invasive (Knosp 3 and 4) and noninvasive (Knosp 0, 1, and 2) tumors, remission rates within 3-6 months were 50% and 83% in the invasive and noninvasive groups, respectively. We further stratified cases with tumor size ≥20 mm (n=11) using Knosp classification; one case (9%) was Knosp 0, one case (9%) was Knosp 1, two cases (18%) were Knosp 3, and seven cases (64%) were Knosp 4 tumors. For ≥20 mm, all cases with Knosp 0, 1, and 3 tumors achieved remission within 3-6 months postoperatively, while none of the cases with Knosp 4 tumors had remission (p=0.01). All the cases with Knosp 0, 1, and 3 tumors sustained remission, and three cases with Knosp 4 tumor later achieved long-term remission (p=0.3). Of the cases that achieved long-term remission, two underwent STRS, and one had medical therapy with additional STRS.
Of the 96 tissue specimens obtained during ETSS, 71 (74%) stained positive for ACTH and were histologically identified as corticotropic adenomas, while 25 (26%) were negative. Remission rates based on the pathology results are compared in Table 2. Of the lesions with conclusive findings on MRI (≥6 mm lesions), 89% (n=49) were pathologically confirmed as corticotropinomas, whereas 54% (n=22) of those with inconclusive MRI f indings were pathologically conf irmed (p<0.001). Among the lesions that showed negative results for both conclusive MRI findings (≤5 mm) and pathologic confirmation (negative for a corticotropinoma) (n=19), 12 (63%) showed remission at 3-6 months and 14 (74%) showed remission during long-term follow-up.
During the exploration of the cavernous sinus in one patient (1%), postoperative lateral gaze paralysis of the eye developed due to right abducens nerve palsy. The patient was treated with anti-inflammatory doses of steroids, and the symptom completely resolved within 1 month. In three other patients (3%), severe epistaxis was observed in the postoperative period, 1 to 3 weeks after surgery. Nasal packing was applied for 3 days. Additionally, three patients (3%) experienced postoperative rhinorrhea. To address this issue, a reconstruction of the skull base was performed using fat tissue harvested from the leg, fascia lata graft, and tissue adhesive material. These patients were monitored with a lumbar drain for 1 week. Among the patients who developed rhinorrhea, one patient also developed meningitis and received intravenous antibiotic therapy for about 3 weeks and, the situation compeletly resolved during follow-up. The postoperative complications are summarized in Table 3. Comparison of various characteristics of the cases with and without medium and long-term remission are presented in Table 3, respectively.

Table 3.

Comparison of cases with and without remission, postoperative complications

3−6-month remission


Long-term remission


Number of cases (n=96)
Remission (+) (n=74) Remission (-) (n=22) p-value Remission (+) (n=79) Remission (-) (n=17) p-value
Operation 0.500 0.08
 First time 62 (83.8) 17 (77.3) 66 (83.5) 13 (76.5)
 Re-operation 12 (16.2) 5 (22.7) 13 (16.5) 4 (23.5)
Tumor characteristics 0.003* 0.20
 MST
  Grade 1 31 (42.0) 10 (45.0) 33 (41.8) 8 (47.1)
  Grade 2 22 (30.0) 2 (9.0) 22 (27.8) 2 (11.8)
  Grade 3 17 (23.0) 3 (14.0) 17 (21.5) 3 (17.6)
  Grade 4 4 (5.0) 7 (32.0) 7 (8.9) 4 (23.5)
 Knosp classification <0.001* 0.01*
  0 41 (56.0) 11 (50.0) 44 (55.5) 9 (53.0)
  1 21 (28.0) 1 (4.5) 21 (26.5) 2 (12.0)
  2 4 (5.0) 2 (9.0) 3 (4.0) 1 (6.0)
  3 7 (10.0) 1 (4.5) 7 (9.0) 1 (6.0)
  4 1 (1.0) 7 (32.0) 4 (5.0) 4 (23.0)
 Hardy classification 0.09 0.06
  0A 32 (43.2) 9 (41.0) 34 (43.0) 7 (41.0)
  1A 12 (16.2) 2 (9.0) 12 (15.0) 2 (12.0)
  1E 3 (4.0) 1 (4.5) 3 (4.0) 1 (6.0)
  2A 5 (6.7) 0 (0.0) 5 (6.0) 0 (0.0)
  2E 2 (2.7) 3 (14.0) 2 (3.0) 3 (17.0)
  3A 1 (1.4) 0 (0.0) 1 (1.0) 0 (0.0)
  3B 2 (2.7) 0 (0.0) 2 (3.0) 0 (0.0)
  3E 0 (0.0) 1 (4.5) 0 (0.0) 1 (6.0)
  4A 1 (1.4) 0 (0.0) 1 (1.0) 0 (0.0)
  4D 0 (0.0) 1 (4.5) 0 (0.0) 1 (6.0)
  4E 1 (1.4) 2 (9.0) 3 (4.0) 0 (0.0)
  NA 15 (20.3) 3 (13.5) 16 (20.0) 2 (12.0)
Postoperative
 Complication 0.900 0.30
  (+) 10 (13.5) 3 (13.6) 12 (15.2) 1 (5.9)
  (-) 64 (86.5) 19 (86.4) 67 (84.8) 16 (94.1)
 Pathologic diagnosis 0.070 0.30
  Corticotropinoma 58 (78.4) 13 (59.1) 60 (75.9) 11 (64.7)
  Negative 16 (21.6) 9 (40.9) 19 (24.1) 6 (35.3)
 Remission during long-term F/U <0.001*
  (+) 72 (97.3) 7 (31.8)
  (-) 2 (2.7) 15 (68.2)
 Residual tumor 0.001*
  (+) 3 (3.8) 5 (29.4)
  (-) 76 (96.2) 12 (70.6)
 Remission during long-term F/U <0.001*
  (+) 72 (91.1) 2 (11.8)
  (-) 7 (8.9) 15 (88.2)
Postoperative complication
 DI-temporary 4 (4.2)
 DI-permanent 4 (4.2)
 Meningitis 1 (1.0)
 CSF leak 3 (3.1)
 Epistaxis 3 (3.1)
 Cranial nerve palsy, transient 1 (1.0)
Hypopituitarism 4 (4.2)
 Hypocortisolism 2 (2.1)
 Hypothyroidisim 2 (2.1)

Values are presented as number (%). *Statistically significant p-values. MST : maximum size of tumor, NA : not available, F/U : follow up, DI : diabetes insipidus, CSF : cerebrospinal fluid

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DISCUSSION

This study reported an overall postoperative 3-6 month remission rate of 77% and a long-term remission rate of 82% after 3 years of follow-up. The initial and long-term remission rates after first operations were 78% and 82%, respectively, with a recurrence rate of 2.5% over a follow-up period of 3-3.5 years. Additionally, our findings revealed that tumor size >2 cm and extended tumor invasion of the cavernous sinus (Knosp 4) might be associated with lower postoperative remission rates. Patients who showed remission within 3-6 months showed higher rates of long-term remission than those in patients without initial remission.
Pituitary surgery is the first-line treatment modality for CD. ETSS is a safe and less invasive method for treating pituitary adenomas; therefore, it has been increasingly preferred in CD [5,15]. However, the postsurgical outcomes in patients with CD have shown variable remission and recurrence rates [2,4,9,16,17,21,30]. These discrepancies may be attributable to differences in population and number of cases involved in the studies, tumor characteristics, criteria for remission and recurrence used by the centers, laboratory parameters, time of evaluation and followup durations, surgical and imaging techniques used by different centers, and neurosurgical expertise.
In this study, we present the medium- and long-term postoperative results of 96 ETSS procedures performed in 87 patients. The medium-term results (obtained 3-6 months postoperation) were preferred to immediate results since a subset of cases may show delayed remission, and immediate postoperative results could be misleading in almost 6% of cases [37]. The overall medium-term remission rate was 77%, consistent with the results published by Serban et al. [34], who reported an overall remission rate of 77% 2 months postoperation. A larger series of 1106 cases reported an immediate remission rate of 72.5% within 7 days postoperation; however, this rate decreased to 67% after delayed remission rates and recurrences 56 months postoperation were considered [12]. The long-term remission rate obtained over a median period of 3 years was 82% in our series. The increased long-term remission rate was attributed to reoperations, additional medical therapies, and the use of STRS in those who did not show remission initially.
Of the 96 procedures, 79 were performed for the first time. The medium-term remission rate after first operations was 78%. Recent studies have reported remission rates of 74-82% after first operations [12,34]. The recurrence rates reported previously varied between 3% and 66% [5,12,34]. However, the duration of follow-up differed among the studies. Dai et al. [12] and Brady et al. [5] reported recurrence rates of 12% and 3%, respectively, after a follow-up period of 2 years. In contrast, Serban et al. [34] reported a recurrence rate of 17% after a longer followup duration of 6 years. In this series, after a median follow-up period of 3 years, the overall recurrence rate was 2.5%. Residual tumors were observed in five cases (6%), and the reoperation rate after the first operation was 13%. Including the eight patients admitted for reoperation after having undergone their first surgery in another center, 17 cases involved reoperations in our center. Of these cases, 71% (n=12) showed remission between 3-6 months postoperation, while none showed recurrence; thus, the long-term remission rate was 77%. Residual tumors were detected in three cases (18%), and the disease persisted in four (24%) of these 17 reoperated cases. Previous studies have reported remission rates of 22-75% after repeated surgery in CD [5,12,34,38]. Although the success rates after reoperations were lower than those in first-time operations in some studies [38], the remission rates after the first and reoperations did not differ significantly in our study.
Tumor size has been reported to contribute to the success of transsphenoidal surgery [12,34], with microadenomas showing a higher success rate after surgery [5,12,34]. Our remission rates for micro- and macroadenomas were similar to those reported by Dai et al. [12] : 81% for adenomas <10 mm and 68% for adenomas ≥10 mm. However, the statistical significance of our study differed from that in the series presented by Dai et al. [12] (p=0.2 vs. p=0.002). This may be due to the large difference in the number of cases included in the two studies and the differences in size scales for tumors ≥10 mm. In our series, when the tumors were stratified further by the tumor size, the medium-term remission rate further decreased to 36% for tumors ≥20 mm in size, although the remission rates for other groups <20 mm were all above 75% (p=0.003). Sharifi et al. [35] classified pituitary MRI scans in CD showing a tumor size <6 mm as “inconclusive” because incidentalomas are frequent among tumors in this size range, and this size is not indicative of CD. Previously published series reported that the rate of inconclusive MRI scans in CD was 36-64%, and the remission rates varied between 50% and 71% for those with an inconclusive MRI scan [10,24,27,32,33]. In our series, 54% of the preoperative MRI scans were inconclusive. In the series presented by Sharifi et al. [35] and some other series [8,12,32,36], no significant difference was observed between the remission rates of CD cases with and without a conclusive MRI.This finding is controversial since other studies showed decreased remission rates with preoperative inconclusive MRIs [13,40]. Similar to the results reported by Sharifi et al. [35], we did not find a statistically significant difference between the remission rates of tumors <6 mm and those between 6-20 mm. However, a significant difference was observed between tumors <6 mm and those ≥20 mm. Residual tumors were more frequent after operating tumors >20 mm compared to those <20 mm, but the number of reoperations did not differ among the groups. Additionally, tumors >20 mm were primarily Knosp 4 (64%), probably contributing to lower remission rates in this group. Interestingly, two Knosp 3 cases had postoperative remission within 3-6 months without additional intervention. In these two cases, the surgical team explored the cavernous sinus and could resect the tumor. However, complete excision was not feasible with Knosp 4 tumors, where there is a complete encasement of the intracavernous internal carotid artery. Thus, a tumor size of 20 mm may be supportive data in predicting non-remission in the presence of complete cavernous sinus infiltration.
Cavernous sinus invasion, determined by the Knosp classification, and sellar invasion and/or suprasellar extension, determined by the Hardy-Wilson classification, indicate the radiologic status of local invasion in cases of pituitary tumors [20,22,39]. Invasion to surrounding structures and tissues may be a limiting factor for postoperative remission of pituitary tumors. In the series presented by Dai et al. [12], remission rates of corticotropinomas with Knosp grade 4 (definitive cavernous sinus invasion) dropped to 53% from a remission rate of 77% for corticotropinomas with less likely or no cavernous sinus invasion (p<0.001). Similarly, our results showed that both medium- and long-term remission rates for Knosp grade 4 tumors decreased to 13% and 50%, respectively, and were lower than the remission rates in other grades (p<0.001 and p=0.01, respectively). While remission rates in Knosp group 3 were not inferior to noninvasive tumors, remission rates in Knosp group 4 were lower than all the other groups. In this regard, the extent of invasion may be more determinative. In contrast, in our series, the modified Hardy classification did not show a significant effect on postoperative remission rates in medium- and long-term follow-up assessments. Araujo-Castro et al. [3] had previously shown that for pituitary adenomas, the Hardy-Wilson classification lacked utility in predicting postoperative remission compared to the Knosp classification. The difference in the utility of these classifications for predicting postoperative remission may be due to differences in accessing tissues during surgery.
In the present series, 74% (n=71) of tissues were histologically proven to be corticotropinomas, while 26% (n=25) did not show histologic confirmation. Medium- and long-term remission rates did not differ between histologically proven and unproven CD cases (medium-term remission rates, 82% vs. 64%, p=0.07; long-term remission rates, 85% vs. 76%, p=0.3). A conclusive finding of an adenoma on MRI increased the rate of histologic proof of corticotropinoma in our series, implying that adenomas showing a ≥6-mm lesion on MRI more frequently stained positive for ACTH. In previous studies 12-53% of CD did not have postoperative pathologic identification and the rate increased in those with a preoperative inconclusive MRI [25,31,38]. However, this did not have a significant influence on our remission rates. The remission rates did not decrease even for CD cases that were not conclusively detected on MRI and could not be histologically proven. On the other hand, in previous studies, ACTH positivity was higher, and the lack of proof for a corticotropinoma decreased the remission rates [1,12,31,32,34]. The higher remission rates despite reduced localization with MRI and/or lower rates of histologic confirmation in our series may be explained by the successful preoperative IPSS lateralization, surgical exploration, and hemi-hypophysectomy procedure. Furthermore, tumor tissues might have been aspirated along with blood and other materials through the suction tube, potentially resulting in less histological confirmation despite postoperative remission of CD.
Additionally, tumor tissues might have been aspirated along with blood and other materials through the suction tube, potentially resulting in less histological confirmation despite postoperative remission of CD.
The total rate of complications in this series was 20%, and the most frequent complication was diabetes insipidus (DI; 8%, both permanent and temporary). The incidence of hypopituitarism was relatively lower (4%), mainly involving hypocortisolism and hypothyroidism. Recent studies have shown postoperative DI rates of 25-66% and hypothyroidism rates of 11-23% [5,34]. Although our neurosurgical team was experienced in conducting pituitary surgeries, other factors may have resulted in these differences. Since not all the cases were postoperatively followed in our center, with some patients lost to follow-up, there may be missing data.
Comparing cases with and without remission in the medium term, cases of remission frequently involved adenomas >20 mm and less cavernous sinus invasion. Additionally, cases that achieved medium-term remission showed long-term remission more frequently. In the long term, those showing remission had less cavernous sinus invasion and residual tumors compared to those without remission. Therefore, we may conclude that a tumor size of 20 mm may predict medium-term remission, while the absence of/less cavernous sinus invasion, early remission, and absence of residual tumor may predict long-term remission.
This study had limitations. First, the retrospective nature of the study and the limited number of cases, which was inevitable due to the low incidence of CD, may have distorted our results. Although the same neurosurgical team operated on all patients, they were followed up pre and postoperatively at different endocrinology centers, causing difficulty in obtaining the full postoperative data of certain cases. Lastly, some patients recently underwent ETSS; thus, they had a shorter follow-up period. However, we intend to present the longer-term outcomes of all patients in a separate study.
Although ETSS is the first-line treatment for CD, previous studies on the use of ETSS for CD have reported a wide range of remission and recurrence rates, which can be primarily attributed to differences in the surgical experience levels among centers. This trend highlights the need for additional data from experienced centers to resolve the discrepancies in the existing data. Therefore, we present medium- and long-term follow-up data from 96 operations for CD conducted in a center with a high level of experience for ETSS. We believe our study makes a significant contribution to the literature because the findings reconfirm the usefulness of ETSS for the treatment of CD and highlight the importance of the size of the adenoma and presence/absence of cavernous sinus invasion on preoperative MRI in predicting long-term remission postoperatively.
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CONCLUSION

ETSS is a safe and effective method for the treatment of CD. Some characteristics of adenomas, such as size, cavernous sinus invasion, and postoperative residue, may predict long-term remission. A tumor size of 2 cm may be a supporting criterion for predicting remission status in the presence of complete cavernous sinus infiltration. Further studies with larger patient populations are necessary to support this finding.
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Notes

Conflicts of interest

No potential conflicts of interest relevant to this study exist.

Informed consent

Informed consent was obtained from all individual participants included in this study.

Author contributions

Conceptualization : BE, MB, EH; Data curation : EA, OH, DT, MM; Formal analysis : LŞP, DAB, DT, İÇ; Funding acquisition : OT, ÖG, DAB; Methodology : LŞP, İÇ, MM, ÖG; Project administration : BE, SÇ, EH; Visualization : EA, OT, OH; Writing – original draft : BE, MB, SÇ; Writing – review & editing : BE, EH

Data sharing

None

Preprint

None

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Acknowledgements

This manuscript was edited by a certified English Proofreading Service (Editage).
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