Adrenal Oncocytoma: A Rare Tumor with Conflicting Imaging Features

Abstract

Oncocytic adenomas are rare benign tumors that typically originate in organs such as the kidneys, thyroid, parathyroid, salivary glands, or pituitary gland. Oncocytic adenoma of the adrenal gland is extremely rare. It often shows heterogeneous, nonspecific features on anatomic imaging, as well as high ¹⁸F-FDG avidity despite its benign nature. The definitive diagnosis relies on histopathologic examination, including immunohistochemistry. We present an incidentally detected benign adrenal oncocytic adenoma with intense ¹⁸F-FDG uptake mimicking sinister pathologies.

Keywords: 18F-FDG PET/CT; adenoma tumors; adrenal oncocytic tumor; oncocytoma.