Complete and sustained remission of hypercortisolism with pasireotide treatment of an adrenocorticotropic hormone (ACTH)-secreting thoracic neuroendocrine tumor: an n-of-1 trial.

N-of-1 trials can serve as useful tools in managing rare disease. We describe a patient presenting with a typical clinical picture of Cushing's Syndrome (CS). Further testing was diagnostic of ectopic Adrenocorticotropic Hormone (ACTH) secretion, but its origin remained occult. The patient was offered treatment with daily pasireotide at very low doses (300 mg bid), which resulted in clinical and biochemical control for a period of 5 years, when a pulmonary typical carcinoid was diagnosed and dissected. During the pharmacological treatment period, pasireotide was tentatively discontinued twice, with immediate flare of symptoms and biochemical markers, followed by remission after drug reinitiation. This is the first report of clinical and biochemical remission of an ectopic CS (ECS) with pasireotide used as first line treatment, in a low-grade lung carcinoid, for a prolonged period of 5 years. In conclusion, the burden of high morbidity caused by hypercortisolism can be effectively mitigated with appropriate pharmacological treatment, in patients with occult tumors. Pasireotide may lead to complete and sustained remission of hypercortisolism, until surgical therapy is feasible. The expression of SSTR2 from typical carcinoids may be critical in allowing the use of very low drug doses for achieving disease control, while minimizing the risk of adverse events.

Medullary thyroid cancer with ectopic Cushing's syndrome: A multicentre case series.

OBJECTIVE: Ectopic Cushing's syndrome (ECS) induced by medullary thyroid cancer (MTC) is rare, and data on clinical characteristics, treatment and outcome are limited. DESIGN: Retrospective cohort study in three German and one Swiss referral centres. PATIENTS: Eleven patients with MTC and occurrence of ECS and 22 matched MTC patients without ECS were included. MEASUREMENTS: The primary endpoint of this study was the overall survival (OS) in MTC patients with ECS versus 1:2 matched MTC patients without ECS. RESULTS: The median age at diagnosis of ECS was 59 years (range: 35-81) and the median time between initial diagnosis of MTC and diagnosis of ECS was 29 months (range: 0-193). Median serum morning cortisol was 49 µg/dl (range: 17-141, normal range: 6.2-18). Eight (73%) patients received treatment for ECS. Treatment of ECS consisted of bilateral adrenalectomy (BADX) in four (36%) patients and adrenostatic treatment in eight (73%) patients. One patient received treatment with multityrosine kinase inhibitor (MKI) to control hypercortisolism. All patients experienced complete resolution of symptoms of Cushing's syndrome and biochemical control of hypercortisolism. Patients with ECS showed a shorter median OS of 87 months (95% confidence interval [95% CI]: 64-111) than matched controls (190 months, 95% CI: 95-285). Of the nine deaths, four were related to progressive disease (PD). Four patients showed PD as well as complications and comorbidities of hypercortisolism before death. CONCLUSION: This study shows that ECS occurs in advanced stage MTC and is associated with a poor prognosis. Adrenostatic treatment and BADX were effective systemic treatment options in patients with MTC and ECS to control their hypercortisolism. MKI treatment achieved complete remission of hypercortisolism and sustained tumour control in one treated case.

Limited Invasive Protocol: Optimizing Diagnostic Modalities in Corticotropin Mediated Cushing Syndrome.

BACKGROUND: To limit the role of bilateral inferior petrosal sinus sampling (BIPSS) in distinguishing between Cushing disease (CD) and ectopic Cushing syndrome (ECS), recent reports have proposed a noninvasive approach based on a combination of biochemical testing and radiological imaging as an alternative to the conventional invasive strategy (CIS). However, this strategy requires further validation. The current study aimed to evaluate 2 limited invasive protocols (LIP-1 and LIP-2) in limiting the role of BIPSS while maintaining a diagnostic accuracy similar to that of CIS. METHODS: This was a single-center study conducted on individuals with corticotropin-dependent Cushing syndrome. The LIPs were based on performing high-dose dexamethasone suppression (>50% cut-off in first [LIP-1] and >80% in second [LIP-2]) and magnetic resonance imaging of the sella in all individuals and selective use of computed tomography of the chest and abdomen before BIPSS. These LIPs were evaluated for limiting the use of BIPSS, their accuracy, and cost in comparison to CIS. RESULTS: Of the 206 individuals, 114 (97 of CD and 21 of ECS) were eligible for the current study. Using LIP-1, LIP-2, and CIS, BIPSS could have been avoided in 62.3%, 35.9%, and 25.4% of individuals, respectively. The positive predictive value for CD using LIP-1 and LIP-2 was 98.9% and 100%, respectively. The cost per patient evaluated using LIP-1, LIP-2, and CIS was $602.21, $966.81, and $1107.78, respectively. CONCLUSION: LIPs represent an equally accurate, less invasive, and more cost-effective alternative to the CIS for distinguishing between CD and ECS.

Ectopic Cushing's syndrome due to thymic neuroendocrine tumours: a systematic review.

Knowledge of ectopic Cushing's syndrome (CS) due to thymic neuroendocrine tumours (NETs) comes from short series or single cases. Our aim is to perform a systematic review using PubMed, Embase, Scopus, Ovid Medline and Biosis Previews of all cases with ectopic CS due to thymic NETs reported in the last 40 years and describe one illustrative patient attended in our institution. Search of literature: From 162 patients, 58.6% were male and mean age was 34.6 ± 13.9 years-old. Median of symptoms until diagnosis was 6 [2-24] months and 62% had aggressive CS. Imaging was positive in 93.7% (chest X-ray), 97.8% (computed tomography), 80.7% (somatostatin receptor scintigraphy) and median tumour size was 47 [25-68.5] mm. At presentation, 18% had localized disease, 26.2% locally invasive and 55.7% advanced. Eighty-eight present underwent surgery and histological subtypes were atypical (46.7%), typical (30.4%) and carcinoma (21.7%). Tumour persisted or recurred in 70.1%, 63% received radiotherapy and 45.2% chemotherapy. Follow-up median was 26.6 [14.5-57.5] months and mortality was reported in 35.8% with median survival of 38 [19-60] months. MEN-1 mutation was referred in 3.1%. Comparatively, carcinomas had aggressive CS more frequently while atypical showed advanced disease more often. In conclusion, thymic NETs causing ectopic CS are presented as aggressive hypercortisolism in the middle aged population. The disease is commonly extended at diagnosis and persists or recurs after surgery in most patients with a short term high mortality.

Low Diagnostic Utility of Overnight High-Dose Dexamethasone Suppression Test in ACTH-Dependent Cushing's Syndrome.

OBJECTIVE: Overnight high-dose dexamethasone suppression test (ON-HDDST) is a simple test to localize the source of ACTH in patients with ACTH-dependent Cushing's syndrome (CS). However, previous studies have reported its varying accuracy. We studied the utility of ON-HDDST in diagnosing Cushing's disease (CD) in a series of patients with CD and ectopic ACTH syndrome (EAS). METHODS: We conducted a retrospective study of 88 patients with ACTH-dependent CS (plasma ACTH > 20.0 pg/mL), who underwent an ON-HDDST. CD and EAS were diagnosed in 68 and 20 patients, respectively. Patients were investigated using MRI of the sellar region, CT of the thorax/abdomen, Gallium-68-DOTANOC PET scan, and bilateral inferior petrosal sinus sampling as required. RESULTS: Patients with EAS had a significantly higher serum cortisol after ON-HDDST than patients with CD (median [IQR], 19.9 [12.4-31.1] µg/dL vs 9.9 [5.1-25.0] µg/dL, P <.01). A suppressed ON-HDDST (≥50% fall from baseline) was noted in 44 (65%) patients with CD and 3 (15%) patients with EAS (P <.0001). Among patients with CD, cortisol suppression >50% was noted in 35 (76%) of patients with microadenoma and 7 (44%) with macroadenoma. Among patients with EAS, ON-HDDST was suppressed in 1 of 6 patients (17%) with an occult tumor and 2 of 14 patients (14%) with a localized tumor. The ROC curve plotted for the percentage suppression of cortisol had an area under the curve (AUC) of 0.72 (P =.01). The best test parameters, with 65% sensitivity, 85% specificity, 94% positive predictive value, 42% negative predictive value, and 69% accuracy, were at 50% cutoff level. CONCLUSION: The ON-HDDST had a poor diagnostic value in differentiating CD and EAS.

To determine the efficacy of bilateral inferior petrosal sinus sampling in differentiating Cushing disease from ectopic Cushing syndrome.

Management of endogenous Cushing syndrome is based on its aetiology. Increased Adrenocorticotropic Hormone (ACTH) levels are the most common cause of this disorder and, therefore, it is critical to determine the source of ACTH before further management. Dynamic post contrast MRI is currently the most common investigation implied to diagnose pituitary adenoma; however, it comes with the drawback of low specificity and high false positive results. Inferior petrosal sinus sampling (IPSS) is an established invasive procedure performed to differentiate central versus peripheral source of ACTH which, in turn, results in hypercortesolaemia. This is a series of 14 patients who underwent IPSS at the Department of Radiology, Aga Khan University Hospital, Karachi, from January 2006 to December 2018. The case series emphasises the role of IPSS in the management of ACTH-dependent Cushing syndrome and combined efficacy of Dynamic post-contrast MRI and the procedure under focus.

Unusual ectopic ACTH syndrome in a patient with orbital neuroendocrine tumor, resulted false-positive outcome of BIPSS:a case report.

BACKGROUND: Cushing's syndrome has been described as a complex endocrine disorder characterized with high cortisol concentration. Correct and early diagnosis of Cushing's syndrome is challenging. According to the latest guideline, bilateral inferior petrosal sinus sampling (BIPSS) is considered to be the gold standard for the differential diagnosis. However, in some unusual cases, this method may be false positive. Here, we presented a rare case of orbital neuroendocrine tumor secreting adrenocorticotrophic hormone with false positive inferior petrosal sinus sampling. CASE PRESENTATION: A 48-year-old woman was admitted to West China Hospital of Sichuan University, presenting with fatigue, whole body edema for 1 year, alopecia and skin pigmentation for 5 months. Hormonal profiles including plasma cortisol and adrenocorticotrophic hormone (ACTH) measurements and low-dose dexamethasone inhibition test suggested that the patient had Cushing's syndrome. However, during tumor location phase, the results of high-dose dexamethasone inhibition test (HDDST) contradicted desmopressin (DDAVP) stimulation test. Thus, BIPSS was employed, and its results indicated a pituitary origin. Interestingly, MRI of sellar region showed an innocent pituitary but caught a serendipitous lesion in the lateral rectus muscle of left eye, which was later proved to be an orbital neuroendocrine tumor secreting ACTH by pathological and immunohistochemical results. ACTH level of the patients was < 0.1 ng/L and cortisol level was 51.61 nmol/L 1 week after surgery. At 24 months follow-up, the patient appeared stable with no complaints nor any symptoms of Cushing's syndrome, including moon face, purple striate and central obesity. The patient's life quality also improved significantly. CONCLUSION: We reported a rare case of endogenous Cushing's syndrome due to ectopic ACTH secreting from an orbital neuroendocrine tumor. This unique case of orbital EAS suggests that orbital venous blood backflow, owning to abnormal anatomic structures, may possibly lead to false positive BIPSS results.

Ectopic Cushing's syndrome associated with a pheochromocytoma in a dog: a case report.

BACKGROUND: Ectopic Cushing's syndrome (ECS) associated with malignant tumors, such as small cell lung carcinoma, bronchial carcinoids, and pheochromocytoma, has been reported in human medicine. However, ECS related to pheochromocytoma has not been reported in dogs. CASE PRESENTATION: An 11-year-old castrated, male Scottish terrier was diagnosed with a left adrenal mass. Cushing's syndrome was suspected based on clinical signs, including pot belly, polyuria, polydipsia, bilateral alopecia, recurrent pyoderma, and calcinosis cutis. Cushing's syndrome was diagnosed on the basis of consistent clinical signs and repeated adrenocorticotropic hormone (ACTH) stimulation tests. In addition, tests for fractionated plasma metanephrine/normetanephrine suggested a pheochromocytoma. Unilateral adrenalectomy was performed after medical management with trilostane and phenoxybenzamine. Histopathology confirmed a diagnosis of pheochromocytoma without cortical lesions. After surgery, fractionated metanephrine/normetanephrine and the findings of low-dose dexamethasone suppression and ACTH stimulation tests were within the normal ranges without any medication. There were no clinical signs or evidence of recurrence and metastasis on thoracic and abdominal X-rays and ultrasonography up to 8 months after surgery. CONCLUSIONS: Pheochromocytoma should be considered a differential diagnosis for dogs with Cushing's syndrome with an adrenal tumor. A good prognosis can be expected with prompt diagnosis and surgical intervention.

Diagnostic utility of Gallium-68-somatostatin receptor PET/CT in ectopic ACTH-secreting tumors: a systematic literature review and single-center clinical experience.

PURPOSE: Tumors causing ectopic Cushing's syndrome (ECS) are often not visible with conventional imaging. Gallium-68-DOTATATE, DOTATOC, and DOTANOC positron emission tomography/computed tomography (68Ga-SSTR PET/CT) reportedly exhibits greater sensitivity in identifying an ECS source, however, evidence is limited to mainly case reports and a few small retrospective studies. Previous systematic ECS imaging review has shown 68Ga-SSTR PET/CT sensitivity is similar to CT (81.8%) in histologically-proven cases and is 100% in covert-cases, however, the number of patients was small and no occult cases were reported. METHODS: We performed a systematic literature review of 68Ga-SSTR PET/CT use in ECS patients. We also report 6 consecutive patients with confirmed active and occult ECS who underwent 68Ga-DOTATATE PET/CT and were followed at our institution between 2014 and 2019. RESULTS: We identified 33 articles (23 case-reports, 4 case-series, 5 retrospective studies and 1 prospective study) detailing 68Ga-SSTR PET/CT in 69 ECS patients. Overall 68Ga-SSTR PET/CT sensitivity was 64.0%, while in histologically confirmed cases (67 lesions), sensitivity was 76.1%. There were two false-positives cases, both in the adrenal glands. In covert cases, 68Ga-SSTR PET/CT identified 50% of lesions. There were ten occult cases where all imaging failed to identify an adrenocorticotropic hormone source; source remains unknown. In our case series, 68Ga-DOTATATE PET/CT showed decreased uptake in pancreatic neuroendocrine tumor in one patient and did not help identify an ECS source in 5 patients. CONCLUSION: Both this systematic literature review, the largest to date, and our single- center experience demonstrate a lower than previously reported 68Ga-SSTR PET/CT sensitivity for ECS, especially in occult lesions. We suggest that the data on 68Ga-SSTR PET/CT in ECS is subject to publication bias, and false-negatives are likely underreported; it's diagnostic value for ECS needs further study.

Mifepristone in the treatment of the ectopic adrenocorticotropic hormone syndrome.

OBJECTIVES: Mifepristone, a glucocorticoid receptor antagonist, can be used to manage hypercortisolism in patients with ectopic adrenocorticotropic hormone syndrome (EAS) when surgical cure is not feasible. Outcomes of EAS patients treated with mifepristone have been limited to reports of isolated cases. We aimed to determine the efficacy and limitations of mifepristone in the treatment of EAS and to compare outcomes with those of patients who underwent bilateral adrenalectomy. METHOD: A retrospective cohort study of EAS patients from the University of Michigan between 1997 and 2017 was conducted. RESULTS: Of the 55 patients with EAS, 16 were treated with mifepristone: eight neuroendocrine tumours, two carcinomas and six occult tumours. Treatment with mifepristone was most commonly prompted by psychosis, uncontrolled glucose and/or hypertension. The median maintenance dose was 600 mg/d. Amelioration of psychosis was observed within 48 hours in 3/3 patients, and the glycaemic control was improved in 14/16 patients. The median duration of treatment was 9 months, and three patients were treated for more than 24 months. The overall survival at 24 months was equivalent between patients with EAS treated with mifepristone vs bilateral adrenalectomy (N = 12) (P = 0.6). CONCLUSIONS: Mifepristone is effective in treating EAS for over 2 years, and survival was not different from that of patients treated with bilateral adrenalectomy. Aggressive concomitant therapy for hypokalaemia and hypertension is necessary.

Two types of ectopic Cushing syndrome or a continuum? Review.

BACKGROUND: Two types of ectopic Cushing syndrome (ECS) are described: ECS associated with aggressive neoplasms, and ECS with indolent and occult tumors, however, there is a lack of studies that thoroughly review their characteristics. METHODS: A systematic review was carried out on PUBMED of all the papers about the ECS, in order to better define the types of this subcategory of Cushing's syndrome, highlighting the differential aspects between these subgroups. RESULTS: It was found that in 50% of cases the prototypic "aggressive" ECS is caused by small cell lung carcinomas (SCLC). In these cases, the clinical presentation may be atypical, predominating the signs and symptoms derived from the protein catabolism. Cortisol and ACTH levels are extremely high, the clinical presentation is abrupt (< 3-6 months) and the tumor is usually advanced, being impossible a curative treatment. On the other hand, "indolent" ECS is mainly represented by carcinoid tumors (CT). In these cases the clinical presentation overlaps enormously with that of Cushing's disease (CD). Cortisol and ACTH levels are slightly elevated, the clinical presentation is progressive (> 6 months) and the prognosis is usually good, and a curative treatment is possible in about 75% of the cases. CONCLUSION: Although there is no absolute differentiation between the two extremes of ECS, a classification could be established in two groups, guided by its clinical and biochemical characteristics, and mainly by the type and stage of the ACTH-secreting tumor. However, a small percentage of tumors do not fit in this simple grouping, and may present both phenotypes or an intermediate one.

Hypertensive crisis in pregnancy due to a metamorphosing pheochromocytoma with postdelivery Cushing's syndrome.

Pheochromocytomas in pregnancy are rare but potentially lethal. Even rarer is the combination of pheochromocytoma in pregnancy with subsequent development of ectopic Cushing's syndrome. We report a 36-year-old woman, previously diagnosed with essential hypertension, who developed severe hypertension in pregnancy complicated by insulin-dependent gestational diabetes. A cesarean section was performed at 32 weeks following a hypertensive crisis after routine administration of betamethasone. Postnatal persistence of signs and symptoms of catecholamine excess led to the diagnosis of a left adrenal pheochromocytoma. Between diagnosis and planned tumor removal, the patient developed signs and symptoms of Cushing's syndrome (facial edema and hirsutism, myopathy and fatigue). Biochemical testing confirmed hypercortisolism with extremely elevated levels of plasma adrenocorticotropin, urinary cortisol and multiple steroids of a plasma panel that were all normal at previous testing. The previously noradrenergic tumor also started producing epinephrine. Histopathological examination confirmed the pheochromocytoma, which was also immunohistochemically positive for adrenocorticotropin. Full post-surgical recovery was sustained with normal blood pressure and biochemical findings after one year. This report not only underlines the chameleon behavior of pheochromocytoma but also illustrates its potential for a metamorphosing presentation. Corticosteroid administration in pregnancy requires a cautious approach in patients with hypertension.

Second-line tests in the differential diagnosis of ACTH-dependent Cushing's syndrome.

INTRODUCTION: Diagnosing Cushing's syndrome (CS) can be a challenge, especially in ACTH-dependent CS, when it comes to detecting the origin of ACTH secretion. MATERIALS AND METHODS: Retrospective data were collected on 170 patients with ACTH-dependent CS (149 CD, 21 EAS) referring to two endocrinology units, focusing on three non-invasive tests: dexamethasone 8 mg overnight challenge (HDDST); corticotrophin-releasing hormone (CRH) assay and the desmopressin (DDAVP) test. RESULTS: Patients with EAS were slightly older and had higher ACTH, serum and urinary cortisol levels than patients with CD (p < 0.01). CD patients had a stronger ACTH and cortisol response after CRH injection (p < 0.0001), and a more pronounced reduction in cortisol levels after HDDST (p < 0.0001). A threshold percentage ACTH increase after CRH stimulation of 72.4 % was able to identify CD with a sensitivity (SE) of 76 % (95 % CI 68-83) and a specificity (SP) of 100 % (95 % CI 83-100). As for HDDST, a cortisol suppression >52.7 % below the basal level suggested a pituitary origin with a SE of 88 % (95 % CI 81-93) and a SP of 90 % (95 % CI 68-99). There were no cases of EAS with positive responses to both these tests. Increases in ACTH and cortisol levels after the DDAVP test were also higher in CD than in EAS (p < 0.01), though the SE and SP were lower. CONCLUSIONS: Patients with CD showed a stronger response to HDDST and CRH, and the adopted cut-offs showed a good SE and SP in discriminating them from patients with EAS. Concordant tests indicated CD when positive, whereas no response to either test was highly suggestive of EAS. The DDAVP test was of limited utility in the diagnostic phase. In conclusion, the choice of tests may play an important part in the differential diagnosis of ACTH-dependent CS.

Hypercortisolism Manifesting as Severe Weight Loss, Hypokalemia, and Hyperglycemia in the Emergency Department.

BACKGROUND: The concurrence of ectopic adrenocorticotropic hormone (ACTH) syndrome (ectopic Cushing syndrome) and cancer is uncommon in the emergency department (ED) setting, but a constellation of nonspecific signs and symptoms can suggest the presence of Cushing syndrome. CASE REPORT: A 65-year-old woman with diabetes visited the ED complaining of severe weight loss, generalized weakness, and hypokalemia. She was treated for hypokalemia and thrush. She was found to have a lung mass with a large pleural effusion. Upon discovery of the suspected malignancy, the patient was referred to the ED of a comprehensive cancer center, where she was diagnosed with ectopic Cushing syndrome and admitted to the hospital for further evaluation and treatment. WHY SHOULD THE EMERGENCY PHYSICIAN BE AWARE OF THIS?: The emergency physician should be able to recognize Cushing syndrome in cancer patients so that the paraneoplastic syndrome can be managed to avoid complications during cancer treatment.

Ectopic Cushing Syndrome Secondary to Diffuse Idiopathic Neuroendocrine Cell Hyperplasia-A Report of 2 Cases.

Ectopic ACTH secretion (EAS) accounts for 10% to 20% of all Cushing syndrome cases. Diffuse intrapulmonary neuroendocrine cell hyperplasia (DIPNECH), a poorly understood lung disease, is characterized by abnormal proliferation of neuroendocrine cells in the bronchial mucosa. It is thought to be a precursor of pulmonary carcinoid and has been associated with EAS in a handful of cases. We present 2 patients with clinical, radiological, and pathological features of DIPNECH who presented with florid Cushing syndrome secondary to EAS evidenced by rapid onset of symptoms, elevated plasma ACTH, and cortisol levels, and failed high-dose dexamethasone suppression testing. Treatment of hypercortisolism included excision of the involved lung and medical therapy with steroidogenesis inhibitors. Despite the aggressive initial management, hypercortisolism persisted. This case series highlights the importance of considering DIPNECH as a cause for Cushing syndrome in the appropriate clinical scenario and underscores the likelihood that surgery may not be curative because of the diffuse nature of this disease. Given the high mortality associated with EAS, prompt medical therapy, appropriate prophylaxis, and bilateral adrenalectomy can be lifesaving measures when initial surgery fails.

A Rare Cyclic Cushing Syndrome Mystery Illustrates Diagnostic Principles.

Pheochromocytomas predominantly produce catecholamines, and rarely also produce ACTH, causing Cushing syndrome (CS). Cyclic CS, an uncommon presentation of hypercortisolism, poses a diagnostic challenge. We report a 71-year-old woman who developed cyclic ectopic ACTH secretion from a pheochromocytoma. Previous evaluations showed intermittent elevations in cortisol and ACTH levels, normal pituitary magnetic resonance imaging, and an adrenal nodule. On admission, she was hypertensive and had cushingoid features. Bilateral inferior petrosal sinus sampling with desmopressin stimulation and an 8-mg dexamethasone suppression test suggested ectopic ACTH secretion, but ACTH increased during the peripheral desmopressin stimulation test. Plasma normetanephrines were about 2-fold above the upper reference limit. 18F-fluoro-dopa and 68Gallium-DOTATATE positron emission tomography/computed tomography scans, computed tomography, and magnetic resonance imaging identified an adrenal mass. After doxazosin adrenoceptor blockade, she underwent right adrenalectomy; histopathology and immunohistochemistry confirmed an ACTH-secreting pheochromocytoma. Postoperative blood pressure normalized and serum cortisol and plasma ACTH levels were suppressed, requiring physiologic hydrocortisone replacement. This case underscores the importance of considering pheochromocytoma in ACTH-dependent hypercortisolism with elevated metanephrines and an adrenal mass. Timely diagnosis and treatment can reduce morbidity and improve quality of life.

Ectopic adrenocorticotropic hormone-secreting pheochromocytoma with severe metabolic disturbances: A case report.

INTRODUCTION: The occurrence of hypercortisolism resulting from adrenocorticotropic hormone (ACTH)-secreting pheochromocytoma is exceedingly uncommon, with limited documented instances thus far. PRESENTATION OF CASE: We present a case of ectopic ACTH-secreting pheochromocytoma in a patient who suffered from severe metabolic disorders. Our clinical case outlines the diagnostic history, preoperative correction of the patient's metabolic disturbances and surgical strategy for management of a rare ectopic ACTH producing pheochromocytoma. DISCUSSION: Ectopic adrenocorticotropic hormone-secreting pheochromocytoma displays multifaceted clinical features and requires prompt diagnosis and multidisciplinary management in order to overcome the related severe clinical derangements. CONCLUSION: The combination of biochemical and hormonal testing and imaging procedures is mandatory for the diagnosis of ectopic ACTH secretion, and in the presence of an adrenal mass, the possibility of an ACTH-secreting pheochromocytoma should be taken into account.

Delayed Diagnosis of Ectopic Cushing Syndrome.

Here, we present the case of a 40-year-old man in whom the diagnosis of ectopic adrenocorticotropin (ACTH) syndrome went unrecognized despite evaluation by multiple providers until it was ultimately suspected by a nephrologist evaluating the patient for edema and weight gain. On urgent referral to endocrinology, screening for hypercortisolism was positive by both low-dose overnight dexamethasone suppression testing and 24-hour urinary free cortisol measurement. Plasma ACTH values confirmed ACTH-dependent Cushing syndrome. High-dose dexamethasone suppression testing was suggestive of ectopic ACTH syndrome. Inferior petrosal sinus sampling demonstrated no central-to-peripheral gradient, and 68Ga-DOTATATE scanning revealed an avid 1.2-cm left lung lesion. The suspected source of ectopic ACTH was resected and confirmed by histopathology, resulting in surgical cure. While many patients with Cushing syndrome have a delayed diagnosis, this case highlights the critical need to increase awareness of the signs and symptoms of hypercortisolism and to improve the understanding of appropriate screening tests among nonendocrine providers.

Second Malignancy Masquerading as Recurrence of Neuroendocrine Tumor.

Neuroendocrine tumors (NETs) may mimic many endocrine syndromes, including Cushing syndrome (CS) secondary to ectopic ACTH secretion. Radiotherapy (RT) is often used as adjuvant therapy for such persistent or recurrent NETs. However, RT may predispose a susceptible person to a second malignancy. Here, we reported the story of a 37-year-old male, who presented with progressive weight loss, bone pain, and shortness of breath in the emergency department. He was diagnosed with CS secondary to a carcinoid tumor in the bronchopulmonary tree a decade previous and underwent total bilateral adrenalectomy. He also underwent lobectomy, and subsequent RT for a primary NET and was in clinical remission. His presenting symptoms were considered a recurrence of pulmonary NETs. However, the biopsy suggested high-grade mucoepidermoid carcinoma (MEC). MEC of the lung is a rare tumor with a prevalence of <1% of all lung malignancies. MEC of the lung after RT for bronchial NET-causing ectopic CS has not yet been reported in the literature. The present patient did not survive despite achieving remission of CS and primary tumor because of the aggressive second malignancy attributed to RT, which was given for the primary tumor.

Remission of Ectopic Cushing Syndrome Secondary to Medullary Thyroid Cancer With Vandetanib and Selpercatinib.

Medullary thyroid cancer (MTC) is a neuroendocrine tumor associated with activating mutations of the rearranged during transfection (RET) proto-oncogene. These tumors may rarely secrete adrenocorticotropin or corticotropin-releasing hormone, resulting in a paraneoplastic ectopic Cushing syndrome (ECS). Paraneoplastic ECS carries a high risk of mortality, and management is difficult due to the lack of response to antiadrenal therapies. We report on a 37-year-old man who was diagnosed with metastatic MTC and reported symptoms of cortisol excess with laboratory testing in keeping with ECS. He began treatment with vandetanib, a multitargeted tyrosine kinase inhibitor, which resulted in decreased tumor burden as well as clinical and biochemical resolution of ECS. Due to progressive structural disease 10 months later, he was switched to the selective RET inhibitor selpercatinib, which was followed by a rapid reduction of cortisol nearing the threshold of adrenal insufficiency. Tumor markers were also improved, and repeat imaging showed decreased tumor burden. Our case highlights the efficacy of tyrosine kinase inhibitors in the management of paraneoplastic ECS. Selective RET inhibitors may emerge as preferred targeted treatment options due to better efficacy and toxicity profiles compared to multitargeted inhibitors. Clinicians should monitor for adrenal insufficiency with the use of selective RET inhibitors.