Endocrine Abstracts

Introduction: Oncocytic adrenocortical neoplasms (OAN) are very rare tumors and they are usually nonfunctional and benign. Approximately 17% of the adrenal oncocytomas are functional. Their clinical and pathological characteristics are unique. The estimated overall median survival for malignant OANs is more favorable than that of conventional adrenocortical carcinomas.

Case report: We present the case of a 79-year-old male who attended consultations for severe pain in the right side. Among his medical background highlighted high blood pressure and heart failure. Abdominal ultrasound was performed and a solid polylobulated mass was detected in direct contact with the upper pole of the right kidney. Abdominal CT revealed a 9.5×13×12 cm hetegoneous adrenal mass. Overnight low-dose dexamethasone supression test revealed a 0800 h serum cortisol of 0.9 μg/dl. Urinary catecholamines and fractionated metanephrines, plasma testosterone, androstendione and dehydroepiandrosterone levels were within the normal range. Aldosterone and renin levels were compatible with essential hypertension. Adrenalectomy was performed. Histophatological examination described an oncocytic adrenal adenoma. A follow-up thoraco-abdominal scan was performed 6 months after the initial diagnosis and showed a 7 mm lung nodule. Conservative treatment was decided and the TC scan was repeated at 6 months. A 14 mm lung nodule and other smaller pulmonary metastases were discovered. A conservative attitude was decided by the multidisciplinary team due to patient’s refusal to receive treatment together with a non-elevated tumor burden and high cardiac toxicity expected from the chemotherapy. OAN are clasified regarding their biological behavior by their histological features according to the Lin-Weiss-Bisceglia system (LBW). The existence of at least one major criterion defines a malignant oncocytoma (>5 mitotic figures per 50 hp fields, atypical mitoses or invasion pf venous structures), the presence of at least one minor criterion defines a borderline oncocytoma, and the absence of all criteria indicates benignancy. In our case, a lesser criterion was met since it was a tumor larger tnah 10 cm.

Conclusions: Commonly OAN of borderline malignant potential seems to have a relatively benign clinical behavior. However, the major clinical problem is to differentiate benign lesions from malignant ones. Further studies are warranted to determine predictors of malignancy and the length, frecuency and parameters needed to follow-up on patients with oncocytic neoplasms of borderline malignant potencial.