Oncocytic adrenocortical neoplasm (OAN) represents a rare variant of adrenocortical carcinoma (ACC) with less than 150 cases reported in the literature. OANs account for 1.8% of adrenal masses, predominantly in adults and usually presenting as large tumors featuring hormonal secretion in 20% of cases. Accurate histological characterization of OANs is crucial as this subtype is believed to be more indolent in clinical behavior. There are 3 categories of OANs: pure oncocytic, mixed oncocytic and ordinary adrenocortical with focal oncocytic changes. The Weiss scoring system used for ACC overestimates malignancy in OANs, therefore alternatives like the Lin-Weiss-Bisceglia (LWB) system need to be used for proper diagnosis and subsequent evaluation of malignant potential. We report the case of a 63-year-old menopaused female with medical history of well controlled type 2 diabetes and hypertension addressed by her GP for exploration of a large adrenal mass neglected by the patient for four years. On interrogation, the patient was completely asymptomatic. Clinical examination revealed a large palpable mass in the left abdomen, normal BMI, no Cushing or virilization syndrome. Hormonal workup showed important elevation of 17OHprogesterone and DHEAS, increased D4Androstendione and total testosterone. The rest of the hormonal workup was in the normal range. Whole body CT scan was consistent with a left heterogeneous adrenal mass of 14×13.6×11 cm, 42HU spontaneous density with calcifications and necrotic areas and no adenopathy or distant metastasis. Open surgery was performed and excised a 15 cm mass weighing 1140 g. Histologic diagnosis was challenging and demanded a second opinion to finally conclude in favor of a mixed OAN with three major criteria and two minor criteria according to the LWB scoring system and a prognosis of malignant evolution. Adjuvant Mitotane treatment was started after discussion in multidisciplinary meeting. Very close clinical, hormonal and imaging follow-up is required for a minimum of 5 years. Although rare entities, OANs should be considered in the differential diagnosis of large adrenal masses. Histological examination by experienced pathologists using the LWB scoring system is of major importance in order to establish the tumors biologic potential and the patients prognosis.
Keywords: oncocytic adrenocortical neoplasm, adrenal mass
18 - 21 May 2019
European Society of Endocrinology