Peripheral Primitive Neuroectodermal Tumor: Report of Two Cases in Abdomen and Pelvis and Clinical Review of 23 Cases

Peripheral primitive neuroectodermal tumors (pPNETs) are a group of unusual small round cell malignancies arising in children and young adults. These tumors occur primarily in bone and soft tissue of the chest, abdomen/pelvis and extremities. The most common presentations are pain and palpable mass. Features of immunohistochemisty and electromicroscopy establish the diagnosis. The treatment of choice of pPNETs is combined surgical resection and chemotherapy; however, the overall prognosis is usually poor. We present two cases of pPNETs of abdominal and pelvic origin and review the previous cases of pPNETs in National Taiwan University Hospital and discuss the characteristics of abdominal and pelvic pPNETs.