Primitive neuroectodermal tumor (PNET) of the uterine isthmus.

Primitive neuroectodermal tumors (PNETs) of the uterus are very rare. The histogenesis of these tumors is still unknown and the differential diagnosis includes a wide variety of tumor entities. We describe a rare case of a 68-year-old female who presented with persistent vaginal bleeding. Physical examination and CT-scan revealed a large tumor in the uterus. Macroscopically the tumor involved the uterine isthmus. Histological and immunohistochemical examination showed that the tumor fulfilled the diagnostic criteria set for PNET. Only a very small number of cases of PNETs of the uterus have been reported in the literature, thus no definitive conclusions concerning the therapeutic management and prognosis have been ascertained.