FRI239 Oncocytic Adrenocortical Neoplasm Of Uncertain Malignant Potential

Disclosure: K. Barnett: None. A. Sandhu: None. F. Hasan: None. Introduction: Oncocytic adrenocortical neoplasms are a rare histological subtype of adrenal mass, characterized by their abundant eosinophilic cytoplasm. Like other adrenal masses, they can be functional, or hormone-producing, and present on a spectrum from benign to malignant. Case: Our patient is a 31 year old female with a past medical history of anxiety who presented to the ER for right upper quadrant abdominal pain. She described it as a colicky, aching pain, lasting for several minutes at a time. She could identify no known trigger. A CT abdomen with contrast showed cholelithiasis and a hypodense lesion on the right adrenal gland. Her primary care physician (PCP) ordered a follow-up MRI abdomen with contrast that showed an indeterminate, 2.9 cm x 2 cm mass on the right adrenal gland without evidence of microscopic fat. After consultation with an oncologist, her PCP then recommended a PET scan, which showed that the mass was mildly hypermetabolic. She presented to the endocrinology office for further evaluation shortly thereafter. Though her abdominal pain had subsided, she did endorse a 7 lb weight loss, attributed to decreased appetite from anxiety. Additional review of systems was grossly negative. Hormonal work-up, including DHEA, renin, AM cortisol, ACTH, aldosterone, and plasma metanephrines was normal. CT-guided biopsy was deferred in favor of a repeat CT abdomen with adrenal protocol, which showed the adrenal nodule measured 40 HU on unenhanced images, with an absolute contrast washout of 50%. As this was less than the 60% threshold typically utilized to indicate a lipid-poor adenoma, the nodule was deemed indeterminate. Given the concerning features of the mass: its lipid-poor nature on unenhanced CT, metabolic activity on PET scan, and washout that was below the threshold for an adenoma, adrenalectomy was recommended. She underwent a laparoscopic right adrenalectomy, with final pathology showing oncocytic adrenocortical neoplasm of uncertain malignant potential, based on Lin-Weiss-Bisceglia criteria. She was seen by oncology, and they recommended no adjuvant treatment at this time. A repeat CTAP abdomen with adrenal protocol is planned for 1 year after this procedure. Discussion: Given the rarity of oncocytic adrenocortical neoplasms, their classification into benign, uncertain malignant potential, or malignant using Lin-Weiss-Bisceglia criteria is essential to determining appropriate treatment and surveillance. A recent retrospective cohort study showed oncocytic neoplasms with uncertain malignant potential have favorable outcomes, however, patients require continued radiographic surveillance due to the risk of late recurrence. Reference: Shirali AS, et al. Differences in Clinicopathologic Behavior of Oncocytic Adrenocortical Neoplasms and Conventional Adrenocortical Carcinomas. Ann Surg Oncol. 2022;29(9):5555-5563. doi:10.1245/s10434-022-11626-w Presentation: Friday, June 16, 2023