腹盆部外周型原始神经外胚层肿瘤的影像学评价

Radiological evaluation of peripheral primitive neuroectrodermal tumor arising in abdomen-pelvis region

目的分析腹盆部外周型原始神经外胚层肿瘤（pPNET）的CT和MRI表现，提高对此病影像学诊断能力。方法回顾性分析中山大学肿瘤防治中心13例经病理证实的腹盆部pPNET的CT和MRI表现。结果13例患者，发病年龄2—72岁，中位年龄30岁。13例病灶中，腹盆腔内9例，腹膜后间隙软组织2例，右侧肾脏1例，肝脏1例。病变均表现为大小不一的软组织肿块，发生于腹盆腔、右肾脏的病灶边界清楚，而发生于腹膜后软组织、肝脏的病灶呈浸润性生长，边界不清。所有病灶内密度／信号均不均匀，8例伴坏死、囊变，增强后均呈不均匀强化。4例病灶内可见点状、斑片状或不规则形钙化，其中1例为治疗后出现。治疗后5例死亡，好转8例。结论腹盆部pPNET的CT和MRI表现缺乏特异性征象，CT和MRI检查可显示肿瘤的范围、发现远处转移，对确定手术的可切除眭及评价治疗效果有重要参考价值。

Objective To analyze the CT and MRI features of peripheral primitive neuroectrodermal tumor （pPNET） arising in abdomen-pelvis region, and to improve the radiological diagnostic ability of this tumor. Methods The CT and MRI appearances of thirteen abdomen-pelvis region pPNET patients proved pathologically were reviewed retrospectively. Results The age of diagnosis ranged from 2 years to 72 years （median, 30 years ）. The tumors were located in the abdomen and pelvic cavity （nine patients ）, retroperitoneal tissues （two patients）, right kidney （one patient） and liver （one patient）. The radiological appearances of the tumors resembled heterogeneous soft tissue masses, eight masses with cystic or necrotic areas. Masses in abdomen and pelvic cavity and kidney were well-defined; while masses in retroperitoneal tissue and liver were ill-defined. Heterogeneous enhancement with intravenous contrast agents was evident. There are speckled, patching and irregular calcifications in four patients, one of them with calcification after treatment. Five patients died, and eight patients rcmissd on clinical follow-up. Conclusions The radiological features of peripheral PNET are non-specific. CT and MRI are useful in delineating the extent, finding distant metastasis, predicting respectability and monitoring treatment.