Cytologic diagnosis of cholesterol granuloma. A case report.

Cholesterol granuloma is a rare lesion of the orbit occurring in adults and must be distinguished from epidermoid cholesteatoma and other mass lesions of the orbit. We report the case of a 31-year-old man who presented to our institution with right eye proptosis secondary to a soft tissue mass. At surgery, cyst fluid from the lesion was sent for cytologic evaluation. The fluid was remarkable for numerous inflammatory cells, blood breakdown products, multinucleate giant cells and cholesterol crystals. The absence of squamous- or respiratory-type epithelium led to a diagnosis of cholesterol granuloma. This was confirmed by histologic examination of the tissue submitted. The differential diagnosis and cytologic features of orbital lesions are discussed.