外周性原始神经外胚层肿瘤的影像学表现及其病理基础研究

摘要

Objective: To explore the pathology and X-ray, CT and MR images of peripheral primitive neuroectodermal tumors (PPNET) as well as correlate with pathologic results, to improve the diagnostic accuracy of peripheral primitive neuroectodermal tumors. Materials and Methods: X -ray, CT and MRI findings in 10 patients with PPNET were retrospectively analyzed, then correlated with pathology. Results: In the ten lesions 3 were located in the tibia, 1 in humerus, 2 in chest wall, 2 in pelvic bone, 1 in inguinal region, 1 in retroperitoneum. The X-ray findings of 4 cases were lytic bone destruction, lytic lesion with irregular sclerosis and expansion(l case). The CT findings included irregular lytic lesion(4 cases), lytic lesion with rim -like sclerosis and expansion (1 case). Five tumors in soft tissue showed ill -defined, irregular and heterogenous cystic areas. The tumors showed moderate heterogeneous enhancement after injection of contrast agents. The 10 cases in bone and soft tissue MRI findings showed iso- or hyperintensity on T1WI, and heterogeneous hyperintensity on T2WI. The tumors showed heterogeneous enhancement and reticular enhancement after injection of contrast agents. Homer-Wright daisy-group was a specific pathologic feature of PPNETs. According to immunohistochemical results, all tumor cells showed positive for CD99, and showed various degrees of antigen in epithelium, including NSE, Syn, S -100 and Vimentin. Conclusion: If X-ray, CT and MRI can be used reasonably, the accuracy of diagnosis of PPNET can be improved, the definite diagnosis is depended on the pathological and immunohistochemical results.%目的:分析外周性原始神经外胚层肿瘤(PPNET)的X线平片、CT及MRI的影像学表现,并与病理结果对照研究,提高PPNET的诊断水平.资料与方法:回顾性分析10例经病理证实的PPNET X线平片、CT、MRI资料,并与病理结果结合分析.结果:10例PPNET中,3例位于胫骨,1例位于肱骨,2例位于胸壁,2例位于骨盆,1例位于腹股沟,1例位于腹膜后.X线表现为溶骨性骨质破坏4例,伴有骨质硬化和轻度膨胀的溶骨性骨质破坏1例；CT扫描中,表现为不规则的溶骨性骨质破坏4例,伴有环状骨质硬化和轻度膨胀的溶骨性骨质破坏1例,5例发生于软组织的PPNET表现为边界不清且不规则的软组织肿块影,肿块内密度多不均匀伴坏死、囊变,增强后呈中等程度以上不均匀强化；MRI中,10例发生于骨骼及软组织的PPNET,均表现为T1WI均呈中等或稍高信号,T2WI呈不均匀高信号,增强后病灶均呈不均匀明显强化,部分病例可见分隔样强化.病理形态上Homer-Wright菊形团为其特异性表现,免疫组织化学结果,肿瘤均表达CD99,并不同程度地表达(神经元特异性烯醇化酶)NSE、突触素(Syn)、S-100、Vimentin(波形蛋白)等.结论:合理应用X线、CT、MRI检查,可提高PPNET诊断的准确性,确诊仍依赖于病理和免疫组织化学检查.