A Case of Low Grade Malignant Fibrous Histiocytoma in Lateral Canthus

ABSTRACT

PURPOSE: To report a case of malignant fibrous histiocytoma of the lateral canthal area that was diagnosed clinically as a benign epidermal inclusion cyst. CASE SUMMARY: A 49 year-old man presented with a cutaneous mass involving the lateral canthal area. A 0.7-cm cystic lesion was freely movable and non-inflamed. After excisional biopsy, the results of immunohistochemical staining led to a final diagnosis of low-grade malignant fibrous histiocytoma. The specimen from excisional biopsy had margins positive for malignancy; the patient underwent a second procedure for complete resection, and that specimen had tumor-free margins. CONCLUSIONS: Fibrous histiocytoma is a rare disease but may occur in the eyelid. Therefore, when an eyelid tumor progresses rapidly, malignant fibrous histiocytoma should be considered as a diagnosis.