A Case of Leiomyosarcoma of the Conjunctiva

ABSTRACT

PURPOSE: We describe a very rare the leiomyosarcoma that developed in the conjunctiva. METHODS: A 59-year-old man was treated at another hospital two months before presenting to our institution. He had not gotten any better and so was admitted to our hospital. He had normal visual acuity and intraocular pressure. However, we found a geographic, highly vascularized mass involving the corneal limbus in the medial bulbar conjunctiva, from which a pterygium had been removed a year previously. An excision of the mass was carried out to detect a suspected conjunctival intraepithelial neoplasm. RESULTS: Tissue obtained from operation had cells with thin nuclei, spindle cells with pleomorphic cigar-shaped nuclei and eosinophilic cytoplasm, atypical cells, and from four to five mitotic figures under ten high power field. In immunohistochemical staining, Vimentin, Smooth muscle actin (SMA), Desmin, CD68 stained positively and cytokeratin, Cam5.2, S-100, HMB-45, CD 34 stained negatively. We found no clues of other origins from the general physical examination. Considering these factors, we conclude that this was a Stage I, G2T1aN0M0 leiomyosarcoma with moderate differentiation. CONCLUSIONS: Analysis by immunohistochemical staining is necessary to detect leiomyosarcoma in the conjunctiva, as it is very rare and hard to diagnose by the histologic method alone. We report a leiomyosarcoma of the conjunctiva after pterygium excision, and suggest that it be considered a differential diagnosis of conjunctival masses, even though it is very rare.