Conjunctival myxoma. A clinicopathologic study of four cases and a review of the literature.

Myxomas are benign tumors that resemble a primitive mesenchyma and rarely occur in the conjunctiva. A clinicopathologic study of four new cases is reported, with a review of the clinical, structural, and behavioral characteristics of the previously reported eight cases. In this study, histochemical analysis of the mucous substance indicated that hyaluronic acid and chondroitin sulfates were present. On ultrastructural examination, the myxoma cell had secretory vacuoles and numerous intermediate-sized cytoplasmic filaments. Adults of an average age of 50.8 years were most often affected. The most common initial complaint was of a painless, slow-growing conjunctival mass, present for an average of 31 months. These tumors typically had a smooth, fleshy, gelatinous appearance. The high recurrence rate that has been noted in orbital and cardiac myxomas was not a feature of these conjunctival myxomas. With an average follow-up of 29 months, a single excision appeared to have been adequate treatment.