Sclerosing epithelioid fibrosarcoma: a case report.

Sclerosing epithelioid fibrosarcoma (SEF) is a rare variant of fibrosarcoma. It is a mesenchymal neoplasm composed of round to oval cells dispersed in a nestlike or cordlike distribution on a highly collagenous tissue background and is now recognized as a distinct clinical entity. In this report we discuss the presentation, diagnosis, and treatment of SEF. We focus on the unique histologic and immunohistochemical properties of this lesion. It is essential for both the surgeon and the pathologist to be aware of SEF and include it in the differential diagnosis for atypical head and neck neoplasms. Sclerosing epithelioid fibrosarcoma is a rare neoplasm that is now listed among the low-grade neoplasms that may occur in the head and neck. However, its behavior tends to be typical of more aggressive lesions. An awareness of this characteristic of SEF is essential for clinicians and pathologists alike.