Evidence of nerve sheath differentiation and high grade morphology in sclerosing epithelioid fibrosarcoma.

Sclerosing epithelioid fibrosarcoma is a recently described sarcoma in which ultrastructural evidence of fibroblastic differentiation forms part of the diagnostic criteria. This report describes a further case of this tumour, which showed evidence of both fibroblastic and perineurial differentiation by immunohistochemistry and electron microscopy, and which had areas of high grade morphology. The tumour metastasised and the patient died of disease 12 months after presentation. The relevance of these findings to diagnosis and differentiation in these tumours is discussed.