Ectopic ACTH syndrome caused by pheochromocytoma: computed tomography-guided percutaneous ethanol injection as an alternative treatment

Pheochromocytoma With High Adrenocorticotropic Hormone Production Capacity Without Pigmentation and Cushingoid Symptoms: A Case Report With a Literature Review

Pheochromocytoma or paraganglioma (PPGL) originating from chromaffin cells can produce diverse hormones in addition to catecholamines, including adrenocorticotropic hormone (ACTH). In pheochromocytoma, high levels of ACTH might not result in pigmentation as typically observed in Addison's disease, and patients might not exhibit the symptoms of Cushing's syndrome, despite ACTH-dependent hypercortisolism. A 63-year-old male patient with hypertension was admitted to our facility, and computed tomography (CT) revealed a large right adrenal tumor. Despite high plasma ACTH (700-1300 pg/mL) and serum cortisol (90-100 µg/dL) levels, no physical pigmentation or Cushingoid symptoms were observed. Urinary metanephrine and normetanephrine levels reached as high as 16.0 mg and 3.2 mg, respectively. 123I-metaiodobenzylguanidine (MIBG) scintigraphy was negative. Low-dose dexamethasone paradoxically increased ACTH and cortisol levels, indicating the potential positive feedback regulation of both hormones by glucocorticoids. The patient was diagnosed with an ACTH-producing pheochromocytoma and underwent successful laparoscopic surgery to remove the adrenal tumor under the intravenous administration of a high-dose α-blocker and hydrocortisone. The levels of ACTH, cortisol, and urinary metanephrine/normetanephrine returned close to normal after tumor removal. We report a rare case of pheochromocytoma with extremely high ACTH/cortisol production but without pigmentation or Cushingoid symptoms. We also reviewed previous reports of ACTH-producing PPGL regarding the paradoxical regulation of ACTH/cortisol by glucocorticoids, pigmentation, Cushingoid symptoms, and negativity of 123I-MIBG scintigraphy.

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.

Tumor Shrinkage by Metyrapone in Cushing Disease Exhibiting Glucocorticoid-Induced Positive Feedback

Context

Paradoxical increases in serum cortisol in the dexamethasone suppression test (DST) have been rarely observed in Cushing disease (CD). Its pathophysiology and prevalence remain unclear.

Case Description

A 62-year-old woman with suspected CD showed paradoxical increases in cortisol after both 1-mg and 8-mg DST (1.95-fold and 2.52-fold, respectively). The initiation of metyrapone paradoxically decreased plasma adrenocorticotropic hormone (ACTH) levels and suppressed cortisol levels. Moreover, the pituitary tumor considerably shrank during metyrapone treatment.

Ex Vivo Experiments

The resected tumor tissue was enzymatically digested, dispersed, and embedded into Matrigel as 3D cultured cells. ACTH levels in the media were measured. In this tumor culture, ACTH levels increased 1.3-fold after dexamethasone treatment (P < 0.01) while control tumor cultures exhibited no increase in ACTH levels, but rather a 20% to 40% suppression (P < 0.05).

Clinical Study

A cross-sectional, retrospective, multicenter study that included 92 patients with CD who underwent both low-dose and high-dose DST from 2014 to 2020 was performed. Eight cases (8.7%) showed an increase in serum cortisol after both low-dose and high-dose DST.

Conclusion

This is the first report of a patient with glucocorticoid (GC)-driven positive feedback CD who showed both ACTH suppression and tumor shrinkage by metyrapone. Our cohort study revealed that 8.7% of patients with CD patients possibly possess GC-driven positive-feedback systems, thereby suggesting the presence of a new subtype of CD that is different from the majority of CD cases. The mechanisms exhibiting GC positive feedback in CD and the therapeutic approach for these patients remain to be investigated.

Ectopic ACTH- and/or CRH-Producing Pheochromocytomas

CONTEXT

The characteristics of catecholamine-secreting pheochromocytomas have been well studied. However, less is known about the characteristics, management and outcome in patients with ectopic adrenocorticotropic hormone (ACTH) and/or corticotrophin-releasing hormone (CRH)-secreting pheochromocytomas.

OBJECTIVE

To review the characteristics and outcomes of ACTH- and/or CRH-secreting pheochromocytomas.

DATA SOURCE

A systematic search of PubMed/MEDLINE and Web of Science, identifying relevant reports published up to 10 February 2020.

STUDY SELECTION

Original articles, including case reports and case series, reporting individual patient data from patients with ACTH- and/or CRH-secreting pheochromocytomas.

DATA EXTRACTION

Information on sex, age, symptoms at presentation, comorbidities, biochemistry, imaging, histopathology, and outcomes was extracted.

DATA SYNTHESIS

We identified 91 articles reporting on 99 cases of ACTH- and/or CRH-secreting pheochromocytomas (CRH-secreting n = 4). Median age at diagnosis was 49 years (interquartile range 38-59.5) with a 2:1 female to male ratio. Most patients presented with clinical Cushing syndrome (n = 79; 81%), hypertension (n = 87; 93%), and/or diabetes (n = 50; 54%). Blood pressure, glucose control, and biochemical parameters improved in the vast majority of patients postoperatively. Infections were the most common complication. Most cases (n = 70, 88%) with reported long-term outcome survived to publication (median follow-up 6 months).

CONCLUSION

Ectopic ACTH- and/or CRH-secreting pheochromocytoma should be considered in patients presenting with ACTH-dependent Cushing syndrome and adrenal mass. Despite the challenge in diagnosis, patient outcomes appear favorable.

Metyrapone-responsive ectopic ACTH-secreting pheochromocytoma with a vicious cycle via a glucocorticoid-driven positive-feedback mechanism

In ectopic ACTH-secreting pheochromocytoma, combined ACTH-driven hypercortisolemia and hypercatecholaminemia are serious conditions, which can be fatal if not diagnosed and managed appropriately, especially when glucocorticoid-driven positive feedback is suggested with a high ACTH/cortisol ratio. A 46-year-old man presented with headache, rapid weight loss, hyperhidrosis, severe hypertension and hyperglycemia without typical Cushingoid appearance. Endocrinological examinations demonstrated elevated plasma and urine catecholamines, serum cortisol and plasma ACTH. Moreover, his ACTH/cortisol ratio and catecholamine levels were extremely high, suggesting catecholamine-dominant ACTH-secreting pheochromocytoma. Computed tomography revealed a large right adrenal tumor. ¹⁸F-FDG positron emission tomography showed uptake in the area of the adrenal tumor, while ¹²³I-metaiodobenzylguanidine scintigraphy showed no accumulation. His plasma ACTH level paradoxically became elevated after a dexamethasone suppression test. After metyrapone administration, not only serum cortisol but also plasma ACTH levels were exponentially decreased almost in parallel, suggesting a glucocorticoid-driven positive-feedback regulation in this rapidly exacerbated ectopic ACTH-producing pheochromocytoma. Interestingly enough, plasma catecholamine levels were also decreased by metyrapone, although they remained extremely high. He became severely dehydrated due to hypoadrenalism requiring hydrocortisone supplementation. His clinical signs and symptoms were improved, and right adrenalectomy was performed uneventfully, resulting in complete remission of pheochromocytoma and Cushing's syndrome. A glucocorticoid-driven positive-feedback regulation in this ectopic ACTH-secreting pheochromocytoma created a vicious cycle with rapid exacerbation of both hypercortisolemia and hypercatecholaminemia with extremely elevated plasma ACTH level. Metyrapone was clinically effective to stop this vicious cycle; nonetheless, great care must be taken to avoid hypoadrenalism especially when hypercatecholaminemia remained.

Severe Cushing Syndrome Due to an ACTH-Producing Pheochromocytoma: A Case Presentation and Review of the Literature

Adrenocorticotropic hormone (ACTH)-dependent Cushing syndrome is rarely caused by a pheochromocytoma. We present a case of a 46-year-old woman who developed severe hypertension, hypokalemia, and typical Cushingoid features. Investigations revealed extremely high metanephrine, cortisol, and ACTH levels. Imaging showed a 3.8-cm left adrenal mass. Preoperative control of hypertension and hypokalemia was very challenging. The patient was cured after surgical removal of the adrenal mass. We followed this by a review of the literature using the databases Google Scholar and PubMed. A total of 58 cases have been reported to date. In summary, ACTH-producing pheochromocytoma is a rare condition that poses a clinical challenge in the perioperative period. It is important that physicians be aware of such a condition because early recognition and treatment are crucial to decrease morbidity and mortality.

Long-term Results after CT-Guided Percutaneous Ethanol Ablation for the Treatment of Hyperfunctioning Adrenal Disorders

OBJECTIVES:

To evaluate the safety and long-term efficacy of computed tomography-guided percutaneous ethanol ablation for benign primary and secondary hyperfunctioning adrenal disorders.

METHOD:

We retrospectively evaluated the long-term results of nine patients treated with computed tomography-guided percutaneous ethanol ablation: eight subjects who presented with primary adrenal disorders, such as pheochromocytoma, primary macronodular adrenal hyperplasia and aldosterone-producing adenoma, and one subject with Cushing disease refractory to conventional treatment. Eleven sessions were performed for the nine patients. The patient data were reviewed for the clinical outcome and procedure-related complications over ten years.

RESULTS:

Patients with aldosterone-producing adenoma had clinical improvement: symptoms recurred in one case 96 months after ethanol ablation, and the other patient was still in remission 110 months later. All patients with pheochromocytoma had clinical improvement but were eventually submitted to surgery for complete remission. No significant clinical improvement was seen in patients with hypercortisolism due to primary macronodular adrenal hyperplasia or Cushing disease. Major complications were seen in five of the eleven procedures and included cardiovascular instability and myocardial infarction. Minor complications attributed to sedation were seen in two patients.

CONCLUSION:

Computed tomography-guided ethanol ablation does not appear to be suitable for the long-term treatment of hyperfunctioning adrenal disorders and is not without risks.

Conventional and Nuclear Medicine Imaging in Ectopic Cushing's Syndrome: A Systematic Review

CONTEXT

Ectopic Cushing's Syndrome (ECS) can be a diagnostic challenge with the hormonal source difficult to find. This study analyzes the accuracy of imaging studies in ECS localization.

EVIDENCE ACQUISITION

Systematic review of medical literature for ECS case series providing individual patient data on at least one conventional imaging technique (computed tomography [CT]/magnetic resonance imaging) and one of the following: 111In-pentetreotide (OCT), 131I/123I-metaiodobenzylguanidine, 18Ffluoro-2-deoxyglucose-positron emission tomography (FDG-PET), 18F-fluorodopa-PET (F-DOPA-PET), 68Ga- DOTATATE-PET/CT or 68Ga-DOTATOC-PET/CT scan (68Gallium-SSTR-PET/CT).

EVIDENCE SUMMARY

The analysis comprised 231 patients (females, 50.2%; age, 42.617 y). Overall, 52.4%(121/231) had "overt" ECS,18.6% had "occult" ECS, and 29% had "covert" ECS. Tumors were located in the lung (55.3%), mediastinum-thymus (7.9%), pancreas (8.5%), adrenal glands (6.4%), gastrointestinal tract (5.4%), thyroid (3.7%), and other sites (12.8%), and primary tumors were mostly bronchial neuroendocrine tumors (NETs) (54.8%), pancreatic NETs (8%), mediastinum-thymus NETs (6.9%), gastrointestinal NETs (5.3%), pheochromocytoma (6.4%), neuroblastoma (3.2%), and medullary thyroid carcinoma (3.2%). Tumors were localized byCTin66.2%(137/207), magnetic resonance imaging in 51.5% (53/103), OCT in 48.9% (84/172), FDG-PET in 51.7% (46/89), F-DOPAPET in 57.1% (12/21), 131/123I-metaiodobenzylguanidine in 30.8% (4/13), and 68Gallium-SSTRPET/CT in 81.8% (18/22) of cases. Molecular imaging discovered 79.1% (53/67) of tumors unidentified by conventional radiology, with OCT the most commonly used, revealing the tumor in 64%, followed by FDG-PET in 59.4%. F-DOPA-PET was used in only seven covert cases (sensitivity, 85.7%). Notably, 68Gallium-SSTR-PET/CT had 100% sensitivity among covert cases.

CONCLUSIONS

Nuclear medicine improves the sensitivity of conventional radiology when tumor site identification is problematic. OCT offers a good availability/reliability ratio, and FDG-PET was proven useful. 68Gallium-SSTR-PET/CT use was infrequent, despite offering the highest sensitivity.

Ectopic hormone-secreting pheochromocytoma: a francophone observational study

BACKGROUND

Ectopic hormone-secreting pheochromocytomas are rare; only case reports exist in the literature. This condition has been linked with increased malignancy, familial syndromes, and ACTH secretion. We wanted to test these hypotheses and shed light on the nature of ectopic hormone-secreting pheochromocytomas.

METHODS

This is a multicenter (francophone) observational study. Inclusion was based upon abnormal preoperative hormone tests in patients with pheochromocytoma that normalized after removal of the tumor. Where possible, immunohistochemistry was performed to confirm that ectopic secretion came from the tumor.

RESULTS

Sixteen cases were found: nine female and seven male patients. Median age was 50.5 (range 31-89) years. Most presented with hypertension, diabetes, or cushingoid features. Ten patients had specific symptoms from the ectopic hormone secretion. Two had a familial syndrome. Of eight patients with excess cortisol secretion, three died as a result of the tumor resection: two had pheochromocytomas >15 cm and their associated cortisol hypersecretion complicated their postoperative course. The other died from a torn subhepatic vein. The 13 survivors did not develop any evidence of malignancy during follow-up (median 50 months). Symptoms from the ectopic secretion resolved after removal of the tumor. Immunohistochemistry was performed and was positive in eight tumors: five ACTH, three calcitonins, and one VIP.

CONCLUSIONS

Most pheochromocytomas with ectopic secretion are neither malignant nor familial. Most ectopic hormone-secreting pheochromocytoma cause hypercortisolemia. Patients with a pheochromocytoma should be worked up for ectopic hormones, because removal of the pheochromocytoma resolves those symptoms. Associated cortisol secretion needs careful attention.

ACTH-producing pheochromocytoma: clinical considerations and concise review of the literature

We present a patient with a rare cause of ectopic ACTH-dependent Cushing's syndrome, caused by a pheochromocytoma. The case provides clues for a detailed discussion on the pitfalls and diagnostic difficulties in establishing the correct underlying cause of ACTH-dependent Cushing's syndrome. It clearly demonstrates that the relative contributions of clinical, biochemical, and radiological clues in establishing the correct underlying cause of Cushing's syndrome may differ considerably between Cushing's disease and Cushing's syndrome due to ectopic overproduction of ACTH. In addition, the literature concerning ACTH-producing pheochromocytomas is reviewed.