Conjunctival stromal tumor: report of 4 cases.

Abstract

To describe the clinical, histopathologic, immunohistochemical, and ultrastructural features of a case series of benign stromal tumors in the bulbar conjunctiva. Observational case series. Four patients with a conjunctival lesion that were classified histologically as low-grade stromal tumors consisting of spindle-shaped cells with occasional pseudonuclear inclusion and multinucleated cells in a partly myxoid matrix. Four cases of low-grade conjunctival stromal tumors were retrospectively identified in an ophthalmic pathology laboratory database. Patients' records were analyzed for demographic data, clinical appearance, and the postoperative course. Formalin-fixed, paraffin-embedded specimens were routinely processed and stained with hematoxylin and eosin and periodic acid Schiff. Immunohistochemical stains for vimentin, S100, CD34, smooth muscle actin (SMA), CD68, and factor XIIIa were performed. Transmission electron microscopy (TEM) was performed on 3 of the cases. Histopathologic evaluation (including immunostains and TEM) and clinical correlation. All 4 tumors occurred in the bulbar conjunctiva of patients between 41 to 53 years of age. None of the patients developed recurrence after excisional biopsy. Histologically, all tumors exhibited spindle-shaped cells with pseudonuclear inclusions and occasional multinuclear cells. Mitotic figures were not observed. The stroma seemed to be myxoid to collagenous. Immunohistochemical stains were positive for CD34, vimentin, and focally for CD68, but were negative for S100 and SMA. We propose to classify these benign lesions, which share distinct histopathologic features, as "conjunctival stromal tumors." A reactive/inflammatory component needs to be considered in the pathogenesis of this lesion.