[A case of intraocular histiocytosis X].

A solitary massive tumor developed in the left eye of a 61-year-old female who had a history of insulin-independent diabetes mellitus for 20 years and whose left eye had become blind due to repeated anterior uveitis in the recent several years. The eyeball was enucleated and used for further examinations. Intraocular tissues were widely infiltrated by histiocytes, though no extraocular invasion or further metastasis was found. Histological examination including alpha 1-anti-chymotrypsin and S100 staining revealed the features characteristic of histiocytosis X. This is probably a case of intraocular histiocytosis X with no evidence of systemic symptoms.