Background: Oncocytomas are predominantly benign tumors that are well described in the kidney, thyroid and salivary glands. They have also been reported in more rare sites including the pituitary and parathyroid glands, respiratory tract and choroid plexus. The occurrence of these tumors in the adrenal gland, however, represents an extremely exceptional finding.
Case presentation: We report the case of a 34 year-old male patient who presented with a right-sided renal colic. Abdominal ultrasonography revealed lithiasis of the right kidney as well as a right adrenal mass. Computed tomography scan of the abdomen demonstrated a large suprarenal retroperitoneal tumor, 6.5 cm at its largest diameter, with no lymphadenopathy and no other intraabdominal neoplastic sites. All blood and urinary tests were normal apart from elevated serum progesterone and testosterone levels. The latter finding leaded to an MRI scan of the hypophysis that revealed an adenoma. The patient underwent a laparoscopic right adrenalectomy via the lateral transperitoneal approach. A well-circumscribed, encapsulated right adrenal mass was identified. The tumor, with the perirenal fat, was dissected from the liver and superior pole of the right kidney, and completely resected. Gross inspection of the specimen during pathologic examination, revealed a grayish and soft mass, measuring 7.5×6.5×5.2 cm in diameter and weighting 168 g. Immunohistochemical stains for vimentin, synaptophysin and calretinin were positive. Ultrastructurally, the neoplastic cell morphology was consistent with adrenocortical oncocytoma with the presence of myelolipoma foci.
Conclusions: Although very infrequent, oncocytomas should be included in the differential diagnosis of adrenal masses. The potential association of the presented lesion with the adenoma of the hypophysis and elevated progesterone and testosterone levels merit further study.
25 - 29 Apr 2009
European Society of Endocrinology