Desmoplastic trichilemmoma: a rare tumor of the eyelid.

PURPOSE To report an upper eyelid mass which proved to be a desmoplastic trichilemmoma. METHODS A 60-year-old man had a slowly enlarging upper eyelid mass. The tumor was excised. The pathologic evaluation of the tumor was centered on the differential diagnosis. RESULTS The clinical appearance of this lesion is nonspecific and can simulate a verruca, follicular keratosis, or basal cell carcinoma. Central desmoplasia, outer root sheath differentiation of the tumor cells, and CD34 positivity are the main characteristics that allow differentiation from basal cell carcinoma. CONCLUSIONS Proper recognition of a benign neoplasm that may be misdiagnosed as basal cell cancer can prevent aggressive surgical treatment.