A Rare Case of Oncocytic Adrenocortical Neoplasm Mimicking Pheochromocytoma

Presentation Number: SAT 391
Date of Presentation: April 1st, 2017

Sravanthi Sanivarapu*, Alice Kit-wah Lee and Salini Chellappan Kumar
Nassau University Medical Center, East Meadow, NY

Abstract

Introduction:

Oncocytic Adrenocortical neoplasms(OAN) are extremely rare. Only 150 cases of OAN have been reported in the literature. It is most frequently found as an incidental finding between the ages 27–72 years. It is more common in women and in the left gland [1-3]. We report a case of OAN in a 25 year old man with a 6.7 cm right adrenal incidentaloma producing dopamine and a positive MIBG scan.

Case Report:

25 year old Hispanic male with PMH of alcoholism and polysubstance abuse was referred to Endocrinology for palpitation, sweating and elevated BP of 169/111mmHg. ROS was negative. Family history was negative for pheochromocytoma. Vital signs and physical examination was normal. In 2012, CT abdomen showed an incidental 2.1 x 1.6 cm right adrenal lesion. In 6/2015 CT showed a 5.5 x 4 cm solid heterogeneous right adrenal mass. A 24 hour urine study showed elevated dopamine levels of 1276µg/24h(52-480). MRI in 10/2015 showed a 6.7 x 4.7 x 4.5 cm well circumscribed mass of the right adrenal gland with several irregular foci with T2 hyperintense signal compatible with necrosis. MIBG scan showed a focus of increased tracer uptake in region corresponding to lesion seen on MRI. After premedication with α blocker, he underwent right adrenalectomy. The pathology report showed predominant cells with eosinophilic and granular cytoplasm, high nuclear grade and diffuse architectural pattern consistent with OAN favoring an adenoma. Immnunohistochemistry was positive for MART-1, inhibin and calretinin, negative for S-100, Chromogranin, Oct4 and SF-1 consistent with adrenocortical origin. 24 hour urine for dopamine normalized 1 month after surgery.

Discussion:

Only 17% of OAN are functional adrenal masses [1-3]. Only 3 case reports of OAN mimicking pheochromocytoma have been reported. (4-6). Our patient presentation was unique with the tumor on the right side, with an isolated elevation of dopamine and false positive MIBG scan. OAN are classified according to Weiss criteria(7) which include major criteria (mitotic rate of >5 mitoses per 50 high power fields, atypical mitoses and venous invasion), minor criteria (large size >10 cm and huge weight > 200 g, necrosis, capsular invasion, sinusoidal invasion) and definitional criteria(predominantly cells with eosinophilic and granular cytoplasm, high nuclear grade, diffuse architectural pattern). The presence of any one of the major criteria indicates malignancy, one to four minor criteria indicates uncertain potential and the absence of all major and minor criteria indicates benign behavior. Routine imaging studies cannot be used to differentiate benign versus malignant oncocytic neoplasms. Microscopic criteria are able to identify precise histology and clinical behavior, so adrenalectomy is the mainstay of therapy.

 

Nothing to Disclose: SS, AKWL, SCK