不同分级颅内血管外皮细胞瘤的影像学表现与病理对照

目的 对比分析不同分级颅内血管外皮细胞瘤(HPC)的影像学特征.方法 回顾性分析经手术病理证实不同分级HPC 39例,均接受MR平扫及增强扫描,并与病理表现进行对照.结果 39例患者中,WHO Ⅲ级间变型HPC 21例,WHO Ⅱ级HPC 18例,均位于颅内脑外.21例间变型HPC中,20例病灶呈分叶状或不规则形.9例跨叶生长；MR平扫T1 WI呈等、高、低混杂信号20例,等信号1例；T2WI呈高、低混杂信号20例,等信号1例；增强扫描呈不均匀显著强化19例；明显囊变坏死16例,“硬膜尾征”2例,相邻颅骨破坏10例,瘤周水肿明显16例.18例HPC中,病灶呈类圆形9例,跨叶生长3例；MR平扫T1WI呈等、低混杂信号10例,等信号8例；T2WI呈等、高混杂信号10例,等信号8例；增强扫描呈均匀显著强化10例；明显坏死囊变7例,“硬膜尾征”6例,相邻颅骨破坏2例,所有病灶瘤周水肿不明显.病理示间变型HPC Ki-67阳性细胞数平均(18.41±1.31)％,HPC Ki-67阳性细胞数平均(7.12±0.78)％.结论 颅内间变型HPC与HPC影像学表现有所差异,前者具有更明显的分叶状、跨叶生长倾向,肿瘤更易出血、坏死、囊变致信号不均匀,少见“硬膜尾征”,更易破坏邻近颅骨,瘤周水肿明显等特点,可与后者鉴别.

Comparison of imaging and pathological findings of different grade intracranial hemangiopericytoma

Objective To analyze and compare imaging features with pathological findings of different grade intracranial hemangiopericytoma(HPC).Methods Thirty-nine patients of different grade HPC proved with operation and pathology were analyzed retrospectively.Both plain and enhanced MR scans were performed,and the results were compared with pathology.Results In 39 cases,WHO Ⅲ grade anaplastic HPC were found in 21 cases and WHO Ⅱ grade HPC in 18 cases.All the intracranial tumors located outside the brain.Twenty cases were lobulated and 9 growed cross-leaf in 21 anaplastic HPC.On MRI,the lesions showed mixed iso-high-low signal(n=20) or iso-signal(n=1) on plain T1WI,while mixed high-low signal(n=20) or iso-signal(n=1) on plain T2WI.After contrast injection,heterogeneous enhancement was seen in 19 cases.Significant necrosis and cyst were seen in 16 cases,while "dural tail sign" in 2 cases.Ten cases appeared bony destruction and 16 cases showed significant peritumoral edema.Lesions showed oval in 9 patients and growed cross-leaf in 3 of 18 WHO Ⅱ grade HPC.On MRI,the lesions showed mixed iso-low signal(n=10) or iso-signal(n=8) on plain T1WI,while mixed iso-high signal(n=10) or iso-signal(n=8) on plain T2WI.After contrast injection,significantly enhanced uniform was seen in 10 cases.Significant necrosis and cyst were seen in 7 cases,"dural tail sign" in 6 cases and 2 cases appeared bony destruction.No significant peritumoral edema was detected.Pathology showed an average of(18.41±1.31)% Ki-67 positive cells in anaplastic HPC,while of(7.12±0.78)% in WHO Ⅱ grade HPC.Conclusion Imaging findings of intracranial anaplastic HPC and WHO Ⅱ grade HPC are different,the former has more pronounced lobulated,cross-leaf growth tendency,easily bleeding,necrosis,cystic to heterogeneous signal,rare "dural tail sign",more damage near the skull,significant peritumoral edema,etc.that are helpful to the differential diagnosis.