肝脏血管平滑肌脂肪瘤9例临床病理分析

目的探讨肝脏血管平滑肌脂肪瘤(hepatic angiomyolipoma,HAML)的临床病理特点、诊断及鉴别诊断。方法对9例HAML进行临床病理学观察与免疫组化标记及复习有关文献。结果 9例HAML年龄28～56岁,平均44.2岁,均无结节硬化症。术前影像诊断多数为肝癌。眼观:肿瘤直径1.2～14 cm。肝左叶4例、肝尾状叶3例和肝右叶2例。肿瘤境界清楚,无包膜,质地脆、易碎,可见出血、坏死。镜检:瘤组织由上皮样细胞、平滑肌样细胞、脂肪组织和厚壁血管组成。上皮样细胞体积大或巨大,呈多边形,胞质丰富,嗜酸性或空泡状,核仁明显,可见核内包涵体,偶见多核巨细胞。平滑肌样细胞呈梭形,9例中有4例几乎缺如脂肪组织。瘤细胞弥漫性或巢团状排列。瘤组织出血、坏死明显,呈浸润性边缘。免疫组化标记:瘤细胞HMB-45及Melan-A阳性,SMA和vimentin散在阳性,CK、EMA、AFP均阴性。结论 HAML是一种罕见的间叶组织源性肿瘤,多见于女性,组织学上以单一方向分化的大上皮样细胞为主,瘤细胞较为特异的表达HMB-45及Melan-A。免疫组化标记可与其它肝脏肿瘤鉴别。

Hepatic angiomyolipoma: report of nine cases and review of the literature

Purpose To investigate the clinicopathological features,diagnosis and differential diagnosis of hepatic angiomyolipoma(HAML).Methods Nine cases of HAML were analyzed by gross examination,light microscopy and immunohistochemistry.The literature on this tumor was reviewed to discuss the histologic features of HAML and its clinical behavior.Results The average age at diagnosis was 44.2 years(28-56 years).All cases had no evidence of tuberous sclerosis.The preoperative imaging diagnoses were hepatocellular carcinomas in majority.Grossly,8 tumors varied from 1.2-14 cm in greatest dimension(mean 7.17 cm).They were 4 in the left lobe,3 in the caudate lobe,and 2 in the right lobe of the liver.The tumors had clear margins and were not encapsulated,showed fragility with hemorrhage and necrosis.Microscopically,hepatic angiomyolipoma was composed of a varying heterogeneous mixture of four tissue components including epithelioid cells,smooth myoid cells,thick-walled vessels and adipose cells.The epithelioid cells were large or huge,exhibited polygonal appearance with abundant eosinophilic or clear cytoplasm.Some cells contained nucleoli and hyaline pseudoinclusions.Scattered multinucleated cells were occasionally seen.The smooth myoid cells were spindle.Four tumors were almost devoid of fat cells.The neoplastic cells were diffuse or nests in arrangement.The necrotic areas with the neoplasm were common with invasive margin.Immunohistochemistry,the neoplastic cells were positive for HMB-45 and Melan-A.SMA and vimentin were focal stellate positive,but CK,EMA and AFP were negative.Conclusions HAML was a rare benign mesenchymal tumor of the liver with female predominance,monotypic differentiated neoplasm containing large epithelioid cells with more specific HMB-45 and Melan-A expression.HAML may be different from other liver tumors with auxiliary immunohistochemistry.