Ewing sarcoma-primitive neuroectodermal tumor of the uterus: a clinicopathologic, immunohistochemical and ultrastructural study of one case.

INTRODUCTION: Ewing sarcoma-primitive neuroectodermal tumors (ES/PNET) constitute a family of neoplasms characterized by a continuum of neuroectodermal differentiation. ES/PNET of the uterus is rare. There are 43 cases published in the English literature as far as we know. We describe an additional case. CASE REPORT: A 56-year-old woman presented with a 2-month history of irregular menopausal vaginal bleeding. After surgical excision, microscopic, immunohistochemical and electron microscopic examination suggested the diagnosis of ES/PNET. The patient underwent combined chemotherapy consisting of ifosfamide, etoposide, and cisplatin. She was alive with no evidence of recurrence or metastasis after 41 months of the initial operation. DISCUSSION: In spite of the rarity of ES/PNET, we should consider it in the differential diagnosis of small cell neoplasms of the uterus.