Case report of a rare adrenocortical oncocytoma suspected to be an adrenal carcinoma

Abstract

An adrenal oncocytic neoplasm is an extremely rare tumour arising from the adrenal gland and it should be considered in the differential diagnosis of an adrenal incidentaloma, since it is frequently non-functioning. The suspicion for malignancy is high when an adrenal incidentaloma is >4 cm in size; however, adrenal oncocytomas are large, measuring an average of 8 cm, are round and encapsulated, and normally have a benign behaviour. We present a case of a 55-year-old male patient with dyslipidaemia, medicated with simvastatin. Upon complaints of abdominal pain, the general physician asked for an abdominal ultrasound that revealed an adrenal lesion, further characterized with a computed tomography scan, which showed an adrenal lesion measuring 49 x 64 x 56 mm and a calcification focus. The patient was referred to the general surgery and endocrinology department. The analytical study was negative for pheochromocytoma or Cushing's syndrome, which allowed surgery to be conducted, as is recommended. The aim of this case report is to contribute to the knowledge on adrenal oncocytomas, since there is scarce information based on singular experiences.