Fibrous histiocytoma of the lacrimal sac.

Fibrous histiocytoma is a rare tumor whose ocular manifestations usually involve the orbit or, less commonly, the conjunctiva and ciliary body. We have treated two patients with fibrous histiocytoma of the lacrimal sac. One, a 62-year-old woman who had had hordeolum and trachoma, had a visual acuity of counting fingers at 1 m in the affected eye. The fellow eye had been enucleated ten years previously. The entire lacrimal sac was surgically removed and a brown cystic tumor measuring 28 x 12 x 10 mm was found. The second patient, a 32-year-old man, had undergone an unsuccessful dacryocystectomy for epiphora. When he underwent a dacryocystorhinostomy some months later, a mass measuring 20 x 15 x 12 mm was found in the wall of the lacrimal sac. Microscopic examination of the two excised lacrimal sacs showed that the walls were thickened by cells resembling fibroblasts and by cells resembling histiocytes. The fibroblasts were characterized by collagen production, were fusiform or oval in shape, and were arranged in bundles. The histiocytes were larger and had abundant (and sometimes vacuolated) cytoplasm. All the cells appeared to be mature.