目的

总结腹膜后原始神经外胚层瘤/尤因肉瘤（PNET/EWS）的临床及组织病理特点,探讨其诊疗方法及预后情况。

方法

分析1例罕见的腹膜后PNET/EWS的临床特征、组织病理学特点以及诊断、治疗方法，同时复习近年来的国内外相关文献。

结果

患者当地医院行左肾切除+左腹膜后肿物部分切除，术后病理示PNET，并在当地医院行化疗。手术后4个月肿瘤复发,再次行手术切除并行化疗，1年后检查发现肿瘤再复发。

结论

腹膜后PNET/EWS是一种小圆形细胞组成的恶性肿瘤。诊断时应与其他腹腔和腹膜后软组织肿瘤相鉴别。治疗以手术切除为主，化疗效果不肯定。本病有侵袭性的临床过程，远处转移早，经常局部复发和区域淋巴结转移，肺、肝、骨和骨髓转移，预后较差。

Objective

To investigate the clinical and histopathologic characteristics of retroperitoneal primitive neuroectodermal tumor with Ewing's sarcoma (PNET/EWS) and study its treatment and prognosis.

Methods

The clinical features,histopathological characteristics,diagnosis,treatment and prognosis of one retrop eritoneal PNET/EWS patient were observed, and relative literatures were reviewed.

Results

The patient was treated with kidney and tumor resection, postoperative chemotherapy was performed in the local hospital. Four months latter,the tumor recurred and was resected,while recurred and was resected again after one year.

Conclusions

Retroperitoneal PNET/EWS is small round-cell tumors.When making diagnisis,it is important to distinguish from other soft tissue sarcoma.Surgical resection is the main therapy measure,but chemotherapy effect is still not affirmed.The tumor is aggressive,local recurrence rate is high,and distant metastasis can always be found.Patients'prognosis is pool.