肾恶性血管平滑肌脂肪瘤一例并文献复习

Maligant renal angiomyolipoma： a case and review of literature

目的 探讨肾恶性血管平滑肌脂肪瘤（MRAML）的临床病理学特点、免疫组化特点及鉴别诊断,以提高对该病的认识.方法 对1例MRAML患者的肿瘤组织进行组织学观察,免疫组化染色,并复习文献.结果 巨检：肿瘤大,灰黄色,质软,边界欠清,伴显著出血坏死.镜检：肿瘤组织示上皮样细胞、平滑肌样细胞以不同比例出现,可见厚壁血管,核分裂象明显,并可见病理性核分裂象及灶状坏死区域.肿瘤细胞特征性表达抗黑素瘤特异性单抗、黑色素-A、兔抗人波形蛋白、肌动蛋白,不表达广谱细胞角蛋白、鼠抗人上皮膜抗原、S-100；Ki67增殖指数＜10％.诊断为（肝脏、右肾后）恶性血管平滑肌脂肪瘤.结论 MRAMC相当罕见,无特异的临床表现,需要根据其组织学及免疫组化特点做出正确诊断.上皮样RAML生物学行为难以预料,患者术后须长期随访.

Objective To explore the clinicalpathological features, immunohistochemical characteristics and differential diagnosis of maligant renal angiomyolipoma（MRAML）. Methods A case with MRAML was exam- ined with light microscopy and immunohistochemistry, including anti-melanoma antibady-45 （HMB-45）, cytokeratin （pan） （CKpan） , epithelial membrane antigen （ EMA）, smooth muscle actin （SMA）, vimentin （ VIM ）, S-100, Ki67, and related literatures were reviewed. Results Grossly, Lesions were large, soft, gray-red and irregular masses, There were predoinant hemorrhage and necrosis. Microscopically, The characteristic histological patterns of tumor was that epithelial cells, smooth muscle ceils and fat ceUsappear in different proportion, thick-walled blood vessels could be seen, the mitoses were obvious, especially the pathologic ones. Immunohistochemically, the tumor cells were positive for HMB-45, SMA, VIM; and negative for CKpan, EMA, S-100; Ki-67 index was less than 5%. Conclusions MRAML is exceedingly rare. This disease has no special clinical feature. MRAML should be diagnosed correctly by criteria of hisitological features supplemented with immunohistochemical findings. Epitheliallike RAML is very difficult to predict the biological behavior, which requires a long-term follow-up.