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

Sclerosing epithelioid fibrosarcoma is a recently described sarcoma in whic h ultrastructural evidence of fibroblastic differentiation forms part of th e 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 hi gh grade morphology. The tumour metastasised and the patient died of diseas e 12 months after presentation. The relevance of these findings to diagnosi s and differentiation in these tumours is discussed.