Ectopic ACTH- and/or CRH-Producing Pheochromocytomas

Cushing Syndrome Due to a Corticotropin-Releasing Hormone- and Adrenocorticotropic Hormone-Secreting Silent Pheochromocytoma

Background/Objective

Ectopic cosecretion of corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) in silent (ie, non-catecholamine-secreting) pheochromocytoma is a rare cause of Cushing syndrome.

Case Report

A 57-year-old woman rapidly developed hypercortisolism, clinically manifesting as fatigue, muscle weakness, weight gain, and worsening hypertension and biochemically characterized by hypokalemia and marked increases in the serum cortisol and plasma ACTH levels. This acute presentation suggested a diagnosis of ectopic ACTH syndrome (EAS). Imaging studies revealed a right adrenal mass that enhanced after administration of the radioisotope gallium-68-DOTATATE. Plasma metanephrines were normal in 2 separate measurements. The possibility of a silent pheochromocytoma was considered. After controlling her hypercortisolism with metyrapone and surgical preparation with alpha blockade, the patient underwent elective right adrenalectomy. Pathology revealed a pheochromocytoma that stained focally for ACTH and CRH. Postoperatively, the cortisol levels normalized, the hypothalamic-pituitary-adrenal axis was not suppressed, and clinical symptoms from hypercortisolism abated.

Discussion

Patients who exhibit a rapid progression of ACTH-dependent hypercortisolism should be screened for EAS. The use of functional imaging radioisotopes (eg, gallium DOTA-peptides) improves the detection of ACTH-secreting tumors. Preoperative treatment with steroidogenesis inhibitors helps control clinical and metabolic derangements associated with severe hypercortisolemia, whereas alpha blockade prevents the onset of an adrenergic crisis.

Conclusion

We present a rare case of EAS due to a silent pheochromocytoma that cosecreted ACTH and CRH. Pheochromocytoma should be considered in patients with EAS who have an adrenal mass even in the absence of excessive catecholamine secretion.

A clinical perspective on ectopic Cushing's syndrome

Cushing's syndrome (CS) refers to the clinical features of prolonged pathological glucocorticoid excess. About 10-20% of individuals with CS have ectopic CS (ECS), that is, an adrenocorticotropin (ACTH)-producing tumour outside the pituitary gland. ACTH-secreting neuroendocrine neoplasia (NENs) can arise from many organs, although bronchial NEN, small cell lung cancer (SCLC), pancreatic NEN, thymic NEN, medullary thyroid cancer (MTC), and pheochromocytoma are the most common. Patients with ECS frequently present with severe hypercortisolism. The risk of life-threatening complications is high in severe cases, unless the hypercortisolism is effectively treated. A good outcome in ECS requires a methodical approach, incorporating prompt diagnosis, tumour localization, control of cortisol excess, and resection of the primary tumour when possible.

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.

Adrenocorticotropic hormone-secreting phaeochromocytoma as a cause of treatment-resistant hypertension and recurrent pulmonary emboli

We report an unusual case of a patient presenting with Cushing's syndrome caused by a phaeochromocytoma secreting adrenocorticotropic hormone (ACTH). The patient had a history of treatment-resistant hypertension, secondary amenorrhoea and tendency towards hypokalaemia. She had multiple signs of Cushing's syndrome, such as swelling, bruising, abdominal striae and proximal myopathy. Hypokalaemia is more common in patients with ectopic ACTH-secretion than other causes of Cushing's syndrome. Computed tomography, adrenal vein sampling and biochemistry could confirm an ACTH-secreting phaeochromocytoma. It is important to consider that hypersecretion of more than one hormone may exist in a unilateral adrenal adenoma. This patient also presented with recurrent pulmonary emboli, and there is an increased risk of venous thromboembolism in patients with ACTH-secreting phaeochromocytoma. Anticoagulation should be considered for as long as the disease is active. We demonstrate that unilateral adrenalectomy can be curative in patients with ACTH-secreting phaeochromocytoma.

Heterogeneity of TPIT expression in ACTH-secreting extra-pituitary neuroendocrine tumors (NETs) supports the existence of different cellular programs in pancreatic and pulmonary NETs

Extra-pituitary ACTH secretion is associated with a variety of neoplastic conditions and may cause the so-called ectopic ACTH-dependent Cushing syndrome (CS). The clarification of the mechanisms of extra-pituitary ACTH expression would provide potential therapeutic targets for this complex and severe disease. In the adenohypophysis, the transcription factor TPIT, co-operating with other molecules, induces POMC expression and ACTH production. However, no data are currently available on the presence and role of TPIT expression in extra-pituitary ACTH-producing neoplasms. This study was designed to explore TPIT expression in a series of pulmonary and pancreatic ACTH-producing tumors, either CS-associated or not. Forty-one extra-pituitary ACTH-producing neuroendocrine tumors (NETs) were included in the study, encompassing 32 NETs of the lung (LuNETs), 7 of the pancreas (PanNETs), and 2 pheochromocytomas. Of these, 9 LuNETs, all PanNETs, and the two pheochromocytomas were CS-associated. For comparison, 6 NETs of the pituitary gland (PitNETs; 3 ACTH-secreting and 3 ACTH-negative) and 35 ACTH-negative extra-pituitary NETs (15 Lu-NETs and 20 PanNETs) were analyzed. Immunohistochemistry with specific anti-TPIT antibodies and quantitative real-time PCR (qRT-PCR) were performed using standard protocols. TPIT expression was completely absent (protein and mRNA) in PanNETs, pheochromocytomas, and all ACTH-negative NETs. In contrast, it was expressed in 16/32 LuNETs, although with lower levels than in PitNETs. No definite relationship was found between immunohistochemistry TPIT expression and NET grade or the presence of Cushing syndrome. This study further highlights the clinical and biological heterogeneity of extra-pituitary ACTH secretion and suggests that the differences between ACTH-secreting PanNETs and LuNETs may mirror distinct molecular mechanisms underlying POMC expression. Our results point towards the recognition of a real corticotroph-like phenotype of ACTH-producing LuNETs, that is not a feature of ACTH-producing PanNETs.

Preoperative management of patients with ectopic Cushing's syndrome caused by ACTH-secreting pheochromocytoma: a case series and review of the literature

PURPOSE

ACTH-secreting pheochromocytoma is a rare cause of ectopic Cushing's syndrome, posing a clinical challenge for the severity of its clinical presentation, the difficulty in the prevention and the management of surgical complications. Sparse data are currently available about the optimal preoperative management of the severe symptoms due to both hypercortisolism and catecholamine excess, especially regarding the role and timing of medical therapies.

METHODS

We present a series of three patients with ACTH-secreting pheochromocytoma. A brief review of the available literature evidence on the preoperative management of this rare clinical condition is also conducted.

DISCUSSION

Patients with ACTH-secreting pheochromocytoma show peculiarities as compared to other forms of ACTH-dependent Cushing's syndrome, in terms of clinical presentation, preoperative management, and peri- and post-surgical short-term outcome. Pheochromocytoma should be ruled out in patient with ectopic CS of unknown origin because of the high anesthesiologic risk of proceeding to surgery with an undiagnosed pheochromocytoma. Proper preoperative recognition of complications of both hypercortisolism and catecholamines excess is the key to prevent the morbidity and mortality of an ACTH-producing pheochromocytoma. In these patients the absolute priority is to control excessive cortisol secretion since the rapid correction of the hypercortisolism is the most effective treatment of all the related comorbidities and it is mandatory to prevent severe complications during surgery, opting if necessary for a "block-and-replace" regimen.

CONCLUSION

Our additional cases and this literature review could provide a better understanding of the complications to be evaluated at diagnosis and some suggestions on their management during the preoperative period.

A Laboratory Medicine Perspective on the Investigation of Phaeochromocytoma and Paraganglioma

Phaeochromocytomas (PC) and sympathetic paragangliomas (PGL) are potentially malignant tumours arising from the adrenal medulla (PC) or elsewhere in the sympathetic nervous system (PGL). These tumours usually secrete catecholamines and are associated with significant morbidity and mortality, so accurate and timely diagnosis is essential. The initial diagnosis of phaeochromocytoma/paraganglioma (PPGL) is often dependent on biochemical testing. There is a range of pre-analytical, analytical and post-analytical factors influencing the analytical and diagnostic performance of biochemical tests for PPGL. Pre-analytical factors include patient preparation, sample handling and choice of test. Analytical factors include choice of methodology and the potential for analytical interference from medications and other compounds. Important factors in the post-analytical phase include provision of appropriate reference ranges, an understanding of the potential effects of various medications on metanephrine concentrations in urine and plasma and a consideration of PPGL prevalence in the patient population being tested. This article reviews these pre-analytical, analytical and post-analytical factors that must be understood in order to provide effective laboratory services for biochemical testing in the diagnosis of PPGL.

Expressions of Cushing's syndrome in multiple endocrine neoplasia type 1

Cushing's syndrome (CS) resulting from endogenous hypercortisolism can be sporadic or can occur in the context of familial disease because of pituitary or extra-pituitary neuroendocrine tumors. Multiple endocrine neoplasia type 1 (MEN1) is unique among familial endocrine tumor syndromes because hypercortisolism in this context can result from pituitary, adrenal, or thymic neuroendocrine tumors and can therefore reflect either ACTH-dependent or ACTH-independent pathophysiologies. The prominent expressions of MEN1 include primary hyperparathyroidism, tumors of the anterior pituitary, gastroenteropancreatic neuroendocrine tumors, and bronchial carcinoid tumors along with several common non-endocrine manifestations such as cutaneous angiofibromas and leiomyomas. Pituitary tumors are present in about 40% of MEN1 patients, and up to 10% of such tumors secrete ACTH that can result in Cushing's disease. Adrenocortical neoplasms occur frequently in MEN1. Although such adrenal tumors are mostly clinically silent, this category can include benign or malignant tumors causing hypercortisolism and CS. Ectopic tumoral ACTH secretion has also been observed in MEN1, almost exclusively originating from thymic neuroendocrine tumors. The range of clinical presentations, etiologies, and diagnostic challenges of CS in MEN1 are reviewed herein with an emphasis on the medical literature since 1997, when the MEN1 gene was identified.

A Rare Cause of Cushing's Syndrome: an Adrenocorticotropic Hormone (ACTH)-Secreting Pheochromocytoma

Cushing's syndrome (CS) is a rare clinical entity that results from prolonged exposure to supraphysiological levels of glucocorticoids. It may result from adrenocorticotropic hormone (ACTH)-dependent or nondependent stimuli. In very rare cases, ACTH production does not derive from the pituitary gland but is of an ectopic origin. We present a case of a 51-year-old woman with cushingoid physical features, who was admitted to the emergency department with a hypertensive crisis, hyperglycemic state, and severe hypokalemia. During the diagnostic workup, the unequivocal confirmation of hypercortisolism status and ACTH elevation led to the suspicion of Cushing's disease. However, additional testing with a corticotropin-releasing hormone test and inferior petrosal sinus sampling suggested against this etiology. Surprisingly, a body computerized tomography scan incidentally revealed the presence of a left adrenal mass with a high uptake in a ⁶⁸Ga-DOTANOC positron emission tomography scan. The further investigation documented elevated urinary metanephrines and normetanephrines. The patient was referred for surgical resection of the adrenal gland, and the anatomopathological report revealed the diagnosis of ACTH-secreting pheochromocytoma without local invasion or malignant features. Diabetes mellitus, hypertension, hypokalemia, and cushingoid stigmata were remitted soon after surgery. ACTH-secreting pheochromocytomas are extremely rare causes of CS. This diagnosis demands a high level of clinical suspicion and should be equated in the presence of severe metabolic changes overlapping CS's physical features. The total reversal of metabolic and clinical symptoms after surgical resection highlights the need to remember this etiology when performing a CS workup.

Gene fusions are frequent in ACTH-secreting neuroendocrine neoplasms of the pancreas, but not in their non-pancreatic counterparts

Ectopic Cushing syndrome is a rare clinical disorder resulting from excessive adrenocorticotrophic hormone (ACTH) produced by non-pituitary neoplasms, mainly neuroendocrine neoplasms (NENs) of the lung, pancreas, and gastrointestinal tract, and other less common sites. The genetic background of ACTH-producing NENs has not been well studied. Inspired by an index case of ACTH-producing pancreatic NEN carrying a gene fusion, we postulated that ACTH-producing NENs might be enriched for gene fusions. We herein examined 21 ACTH-secreting NENs of the pancreas (10), lung (9), thymus (1), and kidney (1) using targeted RNA sequencing. The tumors were classified according to the most recent WHO classification as NET-G1/typical carcinoid (n = 4), NETG-2/atypical carcinoid (n = 14), and NET-G3 (n = 3). Overall, targeted RNA sequencing was successful in 11 cases (4 of 10 pancreatic tumors, 5 of 9 pulmonary tumors, and in the one renal and one thymic tumor). All four successfully tested pancreatic tumors revealed a gene fusion: two had a EWSR1::BEND2 and one case each had a KMT2A::BCOR and a TFG::ADGRG7 fusion, respectively. EWSR1 rearrangements were confirmed in both tumors with a EWSR1::BEND2 by FISH. Gene fusions were mutually exclusive with ATRX, DAXX, and MEN1 mutations (the most frequently mutated genes in NETs) in all four cases. Using RNA-based variant assessment (n = 16) or via the TSO500 panel (n = 5), no pathogenic BCOR mutations were detected in any of the cases. Taken together, gene fusions were detected in 4/4 (100%) pancreatic versus 0/7 (0%) non-pancreatic tumors, respectively. These results suggest a potential role for gene fusions in triggering the ACTH production in pancreatic NENs presenting with ectopic Cushing syndrome. While the exact mechanisms responsible for the ectopic ACTH secretion are beyond the scope of this study, overexpressed fusion proteins might be involved in promoter-mediated overexpression of pre-ACTH precursors in analogy to the mechanisms postulated for EWSR1::CREB1-mediated paraneoplastic phenomena in certain mesenchymal neoplasms. The genetic background of the ACTH-producing non-pancreatic NENs remains to be further studied.

Ectopic Cushing's syndrome from an ACTH-producing pheochromocytoma with a non-functioning pituitary adenoma

Summary

An adrenocorticotropic hormone (ACTH)-producing pheochromocytoma (PCC)/paraganglioma is the cause of ectopic Cushing's syndrome (CS) in 5.2% of cases reported in the literature. We present a previously healthy 43-year-old woman admitted to our hospital with cushingoid features and hypertensive urgency (blood pressure = 200/120 mmHg). Her 24-h urinary free cortisol was >4270 nmol/day (reference range (RR) = 100-380 nmol/day) with a plasma ACTH of 91.5 pmol/L (RR: 2.0-11.5 pmol/L). Twenty-four-hour urinary metanephrines were increased by 30-fold. Whole-body CT demonstrated a 3.7-cm left adrenal mass with a normal-appearing right adrenal gland. Sellar MRI showed a 5-mm sellar lesion. MIBG scan revealed intense uptake only in the left adrenal mass. She was managed pre-operatively with ketoconazole and phenoxybenzamine and underwent an uneventful left laparoscopic adrenalectomy, which resulted in biochemical resolution of her hypercortisolemia and catecholamine excess. Histology demonstrated a PCC (Grading System for Adrenal Pheochromocytoma and Paraganglioma score 5) with positive ACTH staining by immunohistochemistry. A PCC gene panel showed no mutations and there has been no evidence of recurrence at 24 months. This case highlights the difficult nature of localizing the source of CS in the setting of a co-existing PCC and sellar mass.

Learning points

An adrenocorticotropic hormone (ACTH)-producing pheochromocytoma (PCC) is an important item to be considered in all patients presenting with ectopic Cushing's syndrome (CS). In exceptionally rare cases, patients with ectopic CS may present with multiple lesions, and a systematic approach considering all potential sources is crucial to avoid misdiagnosis. CS with a large adrenal mass but lacking contralateral adrenal atrophy should raise suspicion of an ACTH-dependent process. In patients with clinical suspicion of PCC, clinicians should be mindful of the use of steroids and beta-blockers without appropriate alpha blockade as they may precipitate an adrenergic crisis.

Pheochromocytomas and Abdominal Paragangliomas: A Practical Guidance

Simple Summary

Pheochromocytomas and abdominal paragangliomas (PPGLs) are rare. They can be discovered incidentally by imaging with computed tomography or magnetic resonance imaging and during hormonal surveillance in patients with known genetic variants that are associated with PPGLs. As most PPGLs are functioning, a hormonal work-up evaluating for catecholamine excess is recommended. Classical symptoms, such as tachycardia, hypertension and headache, can be present, but when the PPGL is discovered as an incidentaloma, symptoms may be lacking or be more discrete. PPGLs carry malignant potential, and patients should undergo close surveillance, as recurrence of disease or metastasis may develop. Genetic susceptibility for multifocal disease has gained more attention, and germline variants are commonly detected, thus facilitating detection of hereditary cases and afflicted family members. Any patient with a PPGL should be managed by an expert multidisciplinary team consisting of endocrinologists, radiologists, surgeons, pathologists and clinical geneticists.

Abstract

Pheochromocytomas and abdominal paragangliomas (PPGLs) are rare tumors arising from the adrenal medulla or the sympathetic nervous system. This review presents a practical guidance for clinicians dealing with PPGLs. The incidence of PPGLs has risen. Most cases are detected via imaging and less present with symptoms of catecholamine excess. Most PPGLs secrete catecholamines, with diffuse symptoms. Diagnosis is made by imaging and tests of catecholamines. Localized disease can be cured by surgery. PPGLs are the most heritable of all human tumors, and germline variants are found in approximately 30–50% of cases. Such variants can give information regarding the risk of developing recurrence or metastases as well as the risk of developing other tumors and may identify relatives at risk for disease. All PPGLs harbor malignant potential, and current histological and immunohistochemical algorithms can aid in the identification of indolent vs. aggressive tumors. While most patients with metastatic PPGL have slowly progressive disease, a proportion of patients present with an aggressive course, highlighting the need for more effective therapies in these cases. We conclude that PPGLs are rare but increasing in incidence and management should be guided by a multidisciplinary team.

Single-cell transcriptome analysis identifies a unique tumor cell type producing multiple hormones in ectopic ACTH and CRH secreting pheochromocytoma

Ectopic Cushing’s syndrome due to ectopic ACTH&CRH-secreting by pheochromocytoma is extremely rare and can be fatal if not properly diagnosed. It remains unclear whether a unique cell type is responsible for multiple hormones secreting. In this work, we performed single-cell RNA sequencing to three different anatomic tumor tissues and one peritumoral tissue based on a rare case with ectopic ACTH&CRH-secreting pheochromocytoma. And in addition to that, three adrenal tumor specimens from common pheochromocytoma and adrenocortical adenomas were also involved in the comparison of tumor cellular heterogeneity. A total of 16 cell types in the tumor microenvironment were identified by unbiased cell clustering of single-cell transcriptomic profiles from all specimens. Notably, we identified a novel multi-functionally chromaffin-like cell type with high expression of both POMC (the precursor of ACTH) and CRH, called ACTH+&CRH + pheochromocyte. We hypothesized that the molecular mechanism of the rare case harbor Cushing’s syndrome is due to the identified novel tumor cell type, that is, the secretion of ACTH had a direct effect on the adrenal gland to produce cortisol, while the secretion of CRH can indirectly stimulate the secretion of ACTH from the anterior pituitary. Besides, a new potential marker (GAL) co-expressed with ACTH and CRH might be involved in the regulation of ACTH secretion. The immunohistochemistry results confirmed its multi-functionally chromaffin-like properties with positive staining for CRH, POMC, ACTH, GAL, TH, and CgA. Our findings also proved to some extent the heterogeneity of endothelial and immune microenvironment in different adrenal tumor subtypes.

Mixed Corticomedullary Tumor Accompanied by Unilateral Aldosterone-Producing Adrenocortical Micronodules: a Case Report

Mixed corticomedullary tumors (MCMTs) are rare and comprise medullary and cortical cells in a single adrenal tumor. The mechanisms underlying their development have not been fully elucidated. Here, we report a case of MCMT in a 42-year-old woman. Based on the preoperative clinical findings, the patient was diagnosed as having a pheochromocytoma with subclinical Cushing syndrome. Postoperative pathological diagnosis revealed that the tumor demonstrated morphologically distinct medullary and cortical components, which produced catecholamines and cortisol, respectively. Hybrid tumor cells producing both catecholamines and cortisol were not detected. Adrenocorticotropin (ACTH)-positive tumor cells were identified to be present in the pheochromocytoma. This ectopic production of ACTH can contribute to an autonomous cortisol production in a paracrine manner. In addition, micronodules producing aldosterone were detected in the adrenal tissue adjacent to the tumor. The simultaneous development of these 2 lesions may not be correlated with each other; however, this case confirms the importance of a detailed histopathological examination of the adrenal lesions harboring complicated hormonal abnormalities by providing pivotal and indispensable information on their pathogenesis and the possible interaction of the hormones produced in the adrenal gland.

Adrenal Vein Cortisol to Metanephrine Ratio for Localizing ACTH-Independent Cortisol-Producing Adenoma: A Case Report

Context

Finding the source of adrenocorticotropic hormone (ACTH)-independent cortisol-producing adenoma in the patients with subclinical Cushing syndrome (SCS) and bilateral adrenal nodules is sometimes challenging. Computed tomography (CT) and positron emission tomography are helpful, but adrenal venous sampling (AVS) is the gold standard approach. However, interpretation of AVS is important to improve the accuracy of decision-making for surgery. We report a case and review of the literature to assess the benefit of using adrenal vein cortisol to metanephrine ratio to determine the source of cortisol production in SCS and bilateral nodules.

Evidence Acquisition

Three authors searched PubMed for data on patients with SCS who had AVS procedure and measurements of cortisol and catecholamines.

Case Description

A 51-year-old woman with SCS and hypertension crisis presented to our clinic. Paraclinical investigations revealed that she had an ACTH-independent cortisol-producing adenoma and her CT scan showed bilateral adrenal nodules. After AVS, cortisol (high to low) lateralization ratio could not determine the source of cortisol production but the cortisol to metanephrine ratio localized the source to the left side, which included the larger nodule according to CT measurements. Left adrenalectomy led to clinical and paraclinical improvement.

Conclusion

There is a possibility of co-secretion of other steroids accompanied with cortisol in the setting of ACTH-independent SCS. Moreover, cortisol measurement alone and interpretation of AVS results based on cortisol values may not help lateralizing the source of cortisol production with bilateral adrenal nodules. Therefore, we suggest applying cortisol to metanephrine ratio with the same gradient (gradient > 2.3, highest to lowest concentration) when the source of cortisol production cannot be determined by cortisol lateralization ratio.