肝单形性上皮样血管平滑肌脂肪瘤2例临床病理分析

目的 探讨肝单形上皮样血管平滑肌脂肪瘤（MEA）的临床病理学特征及诊断、鉴别诊断要点。方法 对2例MEA进行临床病理学分析、免疫组织化学及电镜研究。结果 患者临床无症状。肿瘤由形态多样的上皮样细胞构成，胞质透亮或嗜酸，无脂肪细胞及异常血管；HMB45（ ），SMA和Vim部分（ ），Des少烤（ ），S-100弱（ ），CK和AFP（-），CD34血管内皮细胞（ ）。电镜下瘤细胞胞质中微丝束上有高电子致密度的凝集物显示，可见黑色素样小体。结论 肝MEA是极为罕见的间叶性肿瘤，组织起源有争议，其诊断及鉴别诊断主要依靠组织病理学、免疫组织化学及电镜检查。

Hepatic monotypic epithelioid angiomyolipoma: two cases report and review of literature

Objective To investigate the clinicopathologic features and differential diagnosis of hepatic monotypic epithelioid angiomyolipoma (MEA). Methods Two cases of MEA were analyzed by clinicopathology, immunohistochemistry and electron microscopy. Results No clinical symptoms were present. Histopathologically, the tumors were composed of pleomorphic epithelioid cells with clear and eosinophilic cytoplasm. Neither adipocytes nor abnormal vessels were recognized in the tumors. Immunohistochemically, the tumor cells were positive for HMB45, focally positive for SMA, desmin and vimentin, weakly positive for S 100 protein and negative for cytokeratins and AFP; CD34 was positive for blood vessel endothelial cells. Ultrastructural observation showed that the tumor cells had premelanosome and dense body. Conclusions MEA of the liver is a rare mesenchymal neoplasm. The pathogenesis is controversial. The diagnosis and differentiatial diagnosis of MEA mainly relies on histopathology, immunohistochemistry and electron microscopic examination.