Abstract
Oncocytoma may be the most common benign mass found in the kidney, but it is a rare entity that can be found in the periocular region. It is described as a shiny, smooth papule arising in the caruncle with histologically glandular features. We describe two cases of periocular oncocytomas. The first case was seen in a 72-year-old man who presented with a new, solitary lesion located at the left medial canthus involving the caruncle. The second was seen in an 86-year-old female who presented with a solitary lesion of the right caruncle. Both specimens revealed well circumscribed proliferations composed of large round epithelial cells with uniformly dense granular eosinophilic cytoplasm and round central nuclei. The epithelial cells formed ducts and cystic spaces, containing abundant eosinophilic acellular material. Goblet cells were also seen interspersed amongst the tubules. Staining performed on the second case showed CK7 highlighting the neoplastic cells. These two cases represent classic findings of the rare periocular oncocytoma. These lesions have characteristic predisposition for the caruncle and a positive cytokeratin profile. The staining reflects the profile of a simple or glandular epithelium, supporting the theory that periocular oncocytic lesions originate from lacrimal duct elements. It is important to recognize this neoplasm, as it can mimic the appearance of other more common caruncular tumors such as hemangiomas or squamous papillomas. Our findings have practical relevance for the clinician who may not be aware of these clinically and pathologically distinctive lesions. Recognition of this neoplasm may assist in reassuring a potential patient of the oncocytomas benign course and low recurrence rate.
Financial Disclosure:
No current or relevant financial relationships exist.
