Primitive neuroectodermal tumors of the abdominal wall and vulva in children: Report of two cases and review of the literature.

Background: Primitive neuroectodermal tumors are rare, highly malignant small round cell tumors belonging to the Ewing sarcoma family. The purpose of this article is to present clinical manifestation, histology, treatment, and prognosis of two primitive neuroectodermal tumors (PNETs) in extremely rare anatomic locations, the abdominal wall and vulva.

Case Summary: Case 1 was a 66-month-old girl with lesions on the abdominal wall; tumor size was about 3.4 cm × 6.1 cm × 2 cm. The patient underwent radical resection of the tumor. After the operation, an alternating vincristine, doxorubicin, and cyclophosphamide/ifosfamide and etoposide (IE) regimen was given for eight cycles, and the patient survived for 66 mo without progression. Case 2 was a 40-month-old girl, with a vulvar lesion; tumor size was about 3.3 cm × 5 cm × 2.5 cm. The tumor was partially resected by surgery. The family left treatment after two cycles of vincristine, pirarubicin, and cyclophosphamide/IE chemotherapy, and the patient died at home six months after surgery.

Conclusion: PNET is a rare, fast-growing, highly malignant tumor that requires histologic and molecular analyses for exact diagnosis, and multimodal treatment is required to achieve a good prognosis.