Purpose: This study aimed to make a nationwide clinicopathological study of oncocytic lesions in the ophthalmic region and to characterize their cytokeratin (CK) expression.
Methods: All histologically diagnosed oncocytic lesions in the ophthalmic region registered in Denmark over a 25-year period were collected and re-evaluated using a monoclonal antimitochondrial antibody (MU213-UC). Clinical data were registered. Immunohistochemical characterization was performed with a panel of anti-CK antibodies.
Results: A total of 34 oncocytic lesions were identified and reviewed. The incidence that required surgical intervention in the Danish population could be approximated to 0.3 lesions per million capita per year. Patient ages ranged from 45 years to 89 years, with a peak incidence in the eighth decade. Female patients were twice as common as male. Lesions were typically described as red–brown, cystic and slow-growing. The antimitochondrial antibody MU213-UC produced a distinct and intense immunostaining of all oncocytic lesions and was found to be useful in substantiating oncocytic differentiation. Twenty-six of the lesions originated in the caruncle, three in the conjunctiva, two in the lacrimal sac, one at the semilunar plica, one on the eyelid margin and one peripunctally. Lesions were histologically classified as adenoma (oncocytoma) (26), hyperplasia (4) and metaplasia (4). Fourteen oncocytic lesions representing different locations and differentiation were further evaluated for CK expression. Basal-type oncocytic cells reacted with antibodies against CK 5/6, CK 7, CK 8, CK 13, CK 14, CK 17, CK 18 and CK 19, and suprabasal cells with CK 4, CK 7, CK 8, CK 18 and CK 19. Antibodies against CK 1+10 and CK 20 showed no reaction.
Conclusions: Oncocytic lesions of the ophthalmic region most frequently present as caruncular oncocytomas. The CK profile is similar to the lacrimal- and accessory lacrimal gland duct elements and supports the theory that these lesions originate in the lacrimal- and accessory lacrimal glands.