子宫恶性血管周上皮样细胞肿瘤临床病理分析

目的:探讨子宫恶性血管周上皮样细胞肿瘤(perivascular epithelioid cell tumor,PEComa)的临床病理特征、免疫表型、诊断及鉴别诊断。方法: 对1例子宫恶性PEComa的临床资料、组织学特征及免疫表型进行分析，并结合文献进行总结。结果: 肿瘤发生于子宫体肌壁间，直径约8.5 cm，术前B超提示为平滑肌瘤待排。镜检:肿瘤浸润性生长，由圆形、多边形上皮样细胞及梭形细胞呈片巢状或绕薄壁不规则血管呈放射状排列，瘤细胞透明或嗜酸，异型明显，有较多瘤巨细胞，核分裂象5个/50HPF，可见大片凝固性坏死。免疫表型:瘤细胞Vimentin、SMA、Desmin阳性，HMB45部分阳性，Ki67约40%阳性。结论:子宫恶性PEComa少见，术前易误诊为平滑肌瘤，免疫组化肌源性标记和黑色素标记双向表达有助于诊断。

Clinicopathological analyses of the uterine malignant perivascular epithelioid cell tumor

Objective:To investigate the clinicopathological features,immunophenotype,diagnosis and differential diagnosis of malignant perivascular epithelioid cell tumor (PEComa) of uterus.Methods:One case of malignnant PEComa of uterus was invetigated by clinical data,pathological feature,immunohistochemical characteristies,and the related literature was reviewed.Results:The tumor occured in the smooth muscle of corpus uteri,and had a diameter of 8.5 cm.Before the operation it was prompted for liomyoma by B-scan images.Microscopic examination:The tumor was invasive growth and composed of round and polyonal epithelial cells or spindle cells.The tumor cells arranged from sheets and/or nests or around irregular thin-walled vessels as radially.The cells with transparent or eosinophilic cytoplasm exhibited obvious atypia and had many giant cells.The mitotic figures were 5/50HPF and massive coagulation necrosis was observed.Immunohistochemically,the tumors were positive for Vimentim,SMA,Desmin and partly positive for HMB45.The positive expression rate of Ki67 was about 40%.Conclusion:Malignant PEComa of uterus is a rare tumor and it is easily misdiagnosed as liomyoma before operation.The bidirectional expression of immunohistochemical muscle and melanin markers is helpful for diagnosis.