[A case of localized histiocytosis X of the eyelid].

A case of localized histiocytosis X of the eyelid was reported. The patient was a 33 year-old man who had a tumorous lesion of the right lower eyelid that had not responded to antibiotic treatment. The lesion, accompanied with induration, slightly protruded on the conjunctival side, and the surface of the lesion was smooth and not ulcerative. No abnormal findings were noted by systemic and laboratory examination results. The patient underwent excision of the lesion and its surrounding tissue in the right lid. The specimen was fixed in formalin and embedded in paraffin. Histopathologic examination revealed diffuse infiltrates of many atypical histiocytes, which were immunohistochemically stained with antibodies to S-100 protein, lysozyme and Leu-M1. The diagnosis of localized histiocytosis X of the lid was made. It is possible that these atypical histiocytes may be classified as a category of T-zone histiocyte immunohistochemically. The postoperative course was uneventful and without recurrence.