Myxomas of the conjunctiva.

Fourteen cases of rare conjunctival myxoma were studied clinicopathologically. The median age of the eight men and six women was 50 years (range, 18 to 76 years). The tumors appeared as slowly growing, freely movable solitary lesions located primarily in the temporal bulbar conjunctiva. The clinical diagnosis was cyst in many cases. The lesions were removed by simple local excision and did not recur. Histologically, they were hypocellular and were composed of stellate and spindle-shaped cells; some had small intracytoplasmic and intranuclear vacuoles. The stroma contained abundant mucoid material and sparse reticulin and delicate collagen fibers. Scattered mast cells were found in many lesions. Ultrastructurally, the intracytoplasmic vacuoles appeared to be extremely dilated cisternae of rough-surfaced endoplasmic reticulum. Invaginations of the nuclear membrane by the cytoplasm correlated with intranuclear vacuoles seen by light microscopy. Conjunctival myxomas are benign tumors and should be differentiated from other benign and malignant soft-tissue tumors with myxomatous features.