SUN-384 Aldosterone Secreting Adrenocortical Carcinoma and the Importance of Initial Imaging

Abstract

Aldosterone secreting adrenocortical carcinomas are extremely rare and aggressive with a reported incidence of 1-2 cases per 1 million population (1). They are known to have poor prognosis often with resistance to adjuvant therapy and tumor recurrence. The assessment of the malignant potential of an adrenal mass is heavily dependent on the image phenotype. In the era of widespread use of CT and magnetic resonance imaging, unexpected adrenal masses are identified more frequently and it is critical to identify surgical candidates. We report a 54 year old man with history of poor follow-up presented in 2013 at another facility with hypertension and persistent hypokalemia. On chart review laboratory evaluation initially revealed an aldosterone 14.2 with a peak of 28 (supine/ambulant <10 ng/dL) and suppressed plasma renin activity 0.53 (.25-5.82 ng/ml per h) including an elevated PRA ratio 26.7. The urinary catecholamines and low-dose dexamethasone-suppression test were noted normal. The initial CT abdomen July 2013 revealed a heterogeneous left adrenal mass measuring 4.3 cm, 53 HU attenuation value with rapid washout of 70%. CT scan in April 2014 revealed growth of the adenoma to 5.4 cm, irregular contours, heterogenous tissue appearance with 74-89 HHU and a washout of 42%. Patient was then taken for open left adrenalectomy Nov 2014 due to significant growth of adenoma. A 7 cm necrotic mass was removed. Pathology report was consistent with a primary adrenocortical carcinoma with lymphovascular invasion and a ki-67 index <10%. The second CT abdomen surveillance completed November 2015 was suspicious for local recurrence with a newly discovered 1.4 cm x 1.4 cm nodule in left surgical bed. Subsequent findings included an enlarging lung nodule and a GE junction ulcerated mass requiring VATS biopsy/wedge resection 2017 and EUS biopsy October 2018 were consistent with metastatic adrenocortical carcinoma. The patient failed multiple therapies including: mitotane, cisplatin/etoposide, and abraxane/gemcitabine. In our case the appearance, density and size of adenoma were initially consistent with malignancy while the washout study favored benignity revealing a suboptimal clinical reliability to the washout study (3). The phenotypic characteristics such as tumor size > 4 cm, heterogenous enhancement, central intramural necrosis with irregular margins should have prompt surgical resection for the best chance of survival (2). Endocrinologist should be a proactive member in reading and confirming the presence of malignancy on imaging. 1. Mills S. (2010) Diagnostic Surgical Pathology, 5th Edition. Lippincott Williams and Wilkins, Baltimore. 2. Ng L, Libertino JM. Adrenocortical carcinoma: diagnosis, evaluation and treatment. J Urol 2003; 169:5-11. 3. Sangwaiya, M. August 2010. Incidental Adrenal Lesions: Accuracy of Characterization with contrast-enhances washout.Radiology Volume 256