Malignant fibrous histiocytoma of the orbit

M. M. Rodrigues, F. P. Furgiuele and S. Weinreb

A 31-year-old woman had a mass in the posterior inferior orbit that progressively increased in size for almost two years. Histopathologic examination of an orbital biopsy specimen showed pleomorphic neoplastic cells arranged in a storiform pattern. The tumor cells were composed of hyperchromatic nuclei with prominent nucleoli and admixtures of fibroblasts. Electron microscopy demonstrated histiocyte-like cells with complex infoldings of plasma membrane, prominent mitochondria and golgi, and free ribosomes. Fibroblast-like cells displayed abundant rough endoplasmic reticulum and adjacent collagen fibrils. The diagnosis was malignant fibrous histiocytoma. An exenteration was performed and postoperative systemic chemotherapy with doxorubicin hydrochloride and methotrexate sodium sulfate was commenced. There was no evidence of recurrence two years later.