Fibrous histiocytoma in primary pterygium.

Fibrous histiocytoma, a mesenchymal tumor, although reported to develop in various ocular structures with a variable frequency, has never been found within a pterygium. We report the case of a 50-year-old female who had had a pterygium for the last six years and had developed a tumor within it one and a half years ago. The tumor was excised along with the pterygium. On histopathological examination the tumor was found to be a benign fibrous histiocytoma arising from within the pterygium.