腹膜后伴有异源性分化的去分化脂肪肉瘤病例分析及文献复习

目的：探讨腹膜后伴有异源性横纹肌肉瘤和神经内分泌分化的去分化脂肪肉瘤分子遗传学特征、临床病理特点、诊断和鉴别诊断。方法回顾性分析1例伴有异源性横纹肌肉瘤和神经内分泌分化的去分化脂肪肉瘤临床病理过程、免疫组织化学、组织形态学特点、诊断，并结合文献复习。结果光镜下肿瘤由两种不同分化成分和形态结构组成，分化成分为分化良好的脂肪瘤样脂肪肉瘤及炎症性、黄色肉芽肿性成分；去分化成分为高度恶性的多形性未分化肉瘤及低度恶性的侵袭性纤维瘤病和黏液纤维肉瘤样成分。去分化成分中可见异源性横纹肌肉瘤及神经内分泌分化。免疫组化：Viment （＋）；CD68（＋）；CDK4（＋）；FLi-1（＋）；MyOD1（＋）；Myogenin（＋）；NSE （＋）；CD56（＋）；CgA （＋/-）；Syn （＋/-）；Bcl-2（＋）；S-100（＋/-）；CD99（＋/-）；Desim（＋）；CD34（-）；LCA（-）；MDM2（-）；CK-AE1/AE3（-）；Ki-67阳性增殖指数＞60％。结论发生在腹膜后的巨大肿瘤，在同一肿瘤内存在两种不同分化成分和形态结构，并伴有异源性成分分化，其复杂性、多形性常造成诊断困难。因此，掌握临床病理及免疫组化特点对该病的诊断和鉴别诊断具有重要意义。

Retroperitoneal dedifferentiated liposarcoma with heterogeneous differentiation:a case report and review of literature

Objective To explore the character of molecular genetics ,clinicopathologic features,diagnosis and differential diagnosis of retroperitoneal dedifferentiated liposarcoma with heterogeneous rhabdomyosarcoma and neuroendocrine differentiation .Methods A retrospective analysis was performed on clinicopathologic process , immu-nohistochemistry , histopathology diagnosis and differential diagnosis in a case of dedifferentiated liposarcoma with het -erogeneous rhabdomyosarcoma and neuroendocrine differentiation and related literature were reviewed .Results There were two elements in the tumor .The differentiated elements included well-differentiated Lipoma-like liposarcoma and inflammation-xanthogranuloma;dedifferentiated element included high-grade malignant pleomorphism undifferentiated sarcoma and low-grade malignant aggressive fibromatosis and myxofibrosarcoma .The dedifferentiation components in-cluded heterogeneous rhabdomyosarcoma and neuroendocrine differentiation .Immunohistochemistry assay showed posi-tive included： Viment,CD68,CDK4,FLi-1,MyOD1,Myogenin,NSE,CD56,Bcl-2,Desim,negative included CD34, LCA,MDM2,CK-AE1/AE3.Suspectde positive included CgA ,Syn,S-100,CD99.Ki-67（ ＋） 〉60%.Conclusion The retroperitoneal enormous tumor has two distinct differentiations and morphologic components with heterogeneous components differentiations .The complexity and polymorphism often make diacrisis difficult .It is important to master histopathology and immunohistochemistry in diagnosis and differential diagnosis of this tumor .