Embryonal (botryoides) rhabdomyosarcoma of the uterus harboring a primitive neuroectodermal tumor component.

The association of a uterine sarcoma botryoides of the adolescence with a primitive neuroectodermal tumor is reported in a 12-year-old patient who presented with abnormal vaginal bleeding that occurred after passing per vaginam a polypoid mass. The sarcoma botryoides of the adolescence exhibited foci of cartilage and a central area of primitive neuroectodermal tumor with a trabecular, adamantiform histology and prominent angiogenesis. Primitive neuroectodermal tumor was positive for vimentin, synaptophysin, neuron-specific enolase, CD99, and SOX2 and negative for both the FLI-1 fusion protein and the rearrangement of ESWR1 gene. The neoplasm exhibited a nonaggressive behavior similar to sarcoma botryoides of the adolescence, being alive and well 3 y after its presentation. This is possibly related to its polypoid nature and the absence of invasive features at its uterine insertion level. A conservative approach without further resection and chemotherapy was indicated taking into account the patient's age.