ACTH-Secreting Pheochromocytoma:  Report of a Case with Long-Term Follow-up after Adrenalectomy

Presentation Number: MON 416
Date of Presentation: April 3rd, 2017

Kamaldeep Panach*1, Jack Michael Raisanen2, Kelley S. Carrick3 and Michael J. McPhaul4
1UTSW Medical Center, Dallas, TX, 2University of Texas Southwestern Medical Center, 3UT Southwestern Medical Center, 4UT Southwestern Med Ctr, Dallas, TX

Abstract

Background:

Ectopic ACTH-secreting tumors are an uncommon cause of Cushing’s syndrome. We report on a patient with an ectopic ACTH-secreting pheochromocytoma.

Clinical Case:

A 58-year-old female with a past medical history of achalasia, type 2 diabetes mellitus and hypertension was referred to our clinic for evaluation of an enlarged right adrenal gland. Her medical history was notable for achalasia and she had undergone endoscopy and Botox injections. She was diagnosed with hypertension two years prior, which had reportedly been difficult to control by her primary care physician. She had associated symptoms of weight gain, facial plethora, supraclavicular fat pads, easy bruising, striae, skin thinning, palpitations, and dizzy spells. Labs were also concerning for persistent hypokalemia.

6 months prior to her presentation to our clinic, she presented to an outside hospital with leukocytosis and rectal prolapse. A chest CT demonstrated a 3.2 cm x 2.5 cm right adrenal tumor heterogeneously enhancing with a central cystic and necrotic component. Subsequent labs revealed elevated metanephrines and urinary free cortisol. She was referred to endocrinology for further evaluation. Biochemical studies revealed elevated ACTH of 149 pg/mL (ref: 10-60 pg/mL), urinary free cortisol of 2714 mcg/24 h (ref: 3.5-45 mcg/24 h), as well as metanephrines of 1175 mcg/24 h (ref: <400 mcg/24 h) and normetanephrines of 1442 ug/24 h (ref: <900 mcg/24 h). MRI brain was normal. Based on labs, a presumptive diagnosis of ACTH-secreting pheochromocytoma was suspected. She was referred to endocrine surgery for surgical evaluation. In the interim, she was started on phenoxybenzamine and medically managed with ketoconazole and insulin. She underwent right retroperitoneoscopic adrenalectomy with findings of an enlarged right adrenal gland. Pathology showed 3.0 x 3.0 x 2.0 cm pheochromocytoma and adrenocortical hyperplasia. Immunohistochemical stains demonstrated expression of chromogranin, synaptophysin, and ACTH by many of the neoplastic cells. Post-operatively the patient did well and was able to come off all antihypertensives.

Conclusion:

We describe a rare case of an ectopic ACTH-dependent Cushing’s syndrome, caused by a pheochromocytoma. Our case highlights the importance of evaluating the entire clinical picture using biochemical and radiographic data.

 

Disclosure: MJM: Employee, Quest Diagnostics, Employee, Quest Diagnostics. Nothing to Disclose: KP, JMR, KSC