Oncocytoma (oxyphilic adenoma) is a benign proliferation of metaplastic apocrine or accessory lacrimal gland epithelium (ie, an adenoma). It typically arises in the caruncle, but it occasionally occurs elsewhere on the conjunctiva. Oncocytoma most commonly occurs in el derly women. Clinically, it appears as a tan to reddish vascularized nodule (Fig 5-27). Histologically, the lesion shows a multicystic proliferation of enlarged polygonal, somewhat columnar, epithelial cells with abundant, intensely eosinophilic granular cytoplasm (reflecting the presence of numerous mitochondria) and periodic acid–Schiff–positive material in the lumen.
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.