Peripheral Primitive Neuroectodermal Tumor of the Pelvis

The primitive neuroectodermal tumor (PNET) belongs to a group of highly malignant tumors and is composed of small round cells of a neuroectodermal origin. Categorized in the same tumor family as Ewing sarcoma, the PNET is most likely to occur in bones and soft tissues. However, a small number of PNET cases arising in the pelvis have been reported as well. We present three cases of pelvic PNET: two cases in the ovary and one case in the broad ligament. The PNET often exhibits aggressive clinical behavior with worse outcomes than other small round cell tumors. The significant prognostic factors of the PNET include site of tumor, volume of neoplasm, and presence of metastasis. The treatment protocol is multimodal and includes local surgical treatment followed by chemotherapy. We herein describe three PNET cases as a rare entity in the pelvis. Pelvic PNETs should be included in the differential diagnosis of pelvic masses.