Benign fibrous histiocytoma of the lower lip.

The fibrous histiocytoma is a soft-tissue neoplasm of the biphasic cell population of fibroblasts and histiocytes that affects the dermis and the subcutaneous tissue. The objective of this article is to report a case of benign fibrous histiocytoma (BFH) of the lower lip in a 32-year-old female patient with a chief complaint of swelling in the lower lip for the past 1 month. With diagnostic clinical hypothesis of fibrous hyperplasia, fibrous histiocytoma and mucocele, an excisional biopsy was performed. The histopathological examination revealed a nonencapsulated proliferation of spindle cells with some giant multinucleated cells in the periphery of the lesion. Multinucleated giant cells and lymphocytes were noted throughout the lesion. Immunohistochemical reactions were performed, staining only CD68 in the multinucleated giant cells. According to these characteristics, the final diagnosis was BFH.