Abstract
Adrenal oncocytomas are rare tumors that are mostly benign and non-functional although they may be hormonally active and can exhibit a borderline or malignant potential. We present a case of a 40-year-old female patient with known hypertension who presented with abdominal discomfort. Radiologic investigations showed a large mass on the left adrenal gland. In the hormonal study, an aldosterone-secreting tumor was identified. After laparoscopic resection, the histological assessment of the 12-cm mass showed an oncocytic neoplasm with borderline characteristics. The laboratory results returned to normal and the hypertensive disease improved. The patient was doing well after 14 months of follow-up. This is the seventh documented case of aldosterone-secreting oncocytoma, the first borderline tumor of this type, and the largest reported tumor so far.