外周性原始神经外胚层肿瘤的影像学表现

目的探讨外周性原始神经外胚层肿瘤(pPNETs)的影像学表现,以提高对本病的认识。方法回顾性分析15例pPNETs的临床及影像学资料,其中软组织pPNETs6例,骨pPNETs9例;7例行X线检查,12例行CT检查,9例行MRI检查。结果骨pPNETsX线及CT平扫表现为范围较广泛、边缘模糊的溶骨性骨质破坏,周围均见大小不等软组织肿块影,大小为2.5cm×2.8cm~10cm×13cm,平均6.2cm×7.4cm;6例病灶增强扫描后见肿块强化,但强化多不均匀。软组织pPNETsCT平扫肿瘤密度不均匀,实质部分为等密度,内可见不同程度的坏死、囊变区;肿瘤大小2.7cm×4.8cm~12.4cm×14.5cm,平均6.7cm×8.2cm;增强扫描后均呈不均匀强化。MRI示病灶T1WI呈等信号6例,等-低混杂信号1例,中等稍高信号2例;T2WI均呈不规则中、高信号;8例钆喷替酸葡甲胺(Gd-DTPA)增强后均表现为不均匀强化。结论pPNETs多表现为溶骨性骨质破坏和(或)巨大软组织肿块,其内常见不同程度的坏死、囊变。CT、MR能较好显示肿瘤的内部结构、明确肿瘤的范围,有助于本病的诊断及鉴别诊断;对判定手术的可切除性、检出远处转移及评价治疗效果等具有较大的价值。

Imaging findings of peripheral primitive neuroectodermal tumors

Objective To study the imaging features of peripheral primitive neuroectodermal tumors (pPNETs), and to be familiar with it. Methods The clinical and imaging information of 15 cases (6 cases in soft tissue and 9 cases in bone) with pathologically proved pPNETs were reviewed retrospectively. X-ray examination (7 cases), CT (12 cases) and MRI (9 cases) were performed in the cases. Results The radiography and CT examination of osteal pPNETs appeared extensive ill-defined osteolysis destruction of bone with inequality of size soft tissue tumors (size 2.5 cm×2.8 cm-10 cm×13 cm, average 6.2 cm×7.4 cm). Uneven enhancement was shown in 6 cases. CT features of soft tissue pPNETs appeared uneven density masses with equal density parenchyma and necrosis, capsular regions. The tumor size was from 2.7 cm×4.8 cm to 12.4 cm×14.5 cm, average 6.7 cm×8.2 cm. The tumor enhanced unevenly. MRI appeared equal signal (6 cases), equal-low confounding signal (1 case), equal-high signal (2 cases) in T1WI. In MRI T2WI, the tumor shown equal-high signal. Eight cases appeared uneven enhancement. Conclusion The imaging manifestation of pPNETs is osteolysis destruction of bone and huge soft tissue mass with necrosis and capsular regions. CT and MRI can appear the internal structures and extent of the tumor, which benefit to diagnosis and differential diagnosis, predicting operative effect, detecting distant metastases and evaluating therapeutic efficacy.