于秀淳　徐明　许宋锋　付志厚　袁冶 

Objective  To investigate the possibility of clinical application of en bloc resection of primitive neuroectodermal tumor (PNET) involving the sacroiliac joint and reconstruction of the pelvic ring. Methods  1 female patient with PNET involving the sacroiliac joint was treated in our hospital in February 2009. She underwent 2 cycles of preoperative chemotherapy and 1 cycle of radiotherapy as the diagnosis was made by preoperative puncture. And then she received en bloc resection and reconstruction of the pelvic ring under general anesthesia. Postoperatively she accepted 10 cycles of chemotherapy. Results  No recurrence and metastasis was found during the postoperative follow-up of 36 months, and she recovered to normal now. Conclusions  It is particularly challenging to treat the patients with malignant bone tumors involving the sacroiliac joint because of the complicated anatomy of tumors and some other problems. However, it is possible to perform en bloc resection of tumors as long as the comprehensive methods such as preoperative chemotherapy, radiotherapy and so on are used and the therapy procedure of malignant bone tumors is strictly followed.