Fibrous histiocytoma of the tarsus

A 21-year-old white man had an asymptomatic eyelid mass that had slowly enlarged for one year. On clinical examination the lesion was well circumscribed; it appeared subconjunctivally but provoked no conjunctival inflammation, and had a consistency suggestive of cartilage. Microscopic examination showed it was matted and composed of elongated fibro-histiocytes and an evenly distributed population of xanthoma cells and Touton giant cells. The lesion was easily removed by local excision because of a pseudocapsule formed by remnants of the tarsus; there has been no recurrence during a 12-month follow-up.