硬化性横纹肌肉瘤临床病理观察

Clinicopathologic features of sclerosing rhabdomyo sarcoma

目的探讨硬化性横纹肌肉瘤(SRMS)的临床病理学特征、免疫表型,提高诊断及鉴别诊断水平。方法对1例硬化性横纹肌肉瘤进行组织形态学及免疫组织化学染色观察,并复习相关文献。结果患者男性,年龄28岁,肿瘤位于右侧咬肌,大小3 cm x2.5 cm x2 cm,边界尚清,质硬。镜下见肿瘤间质显著玻璃样变性,嗜伊红染色,似骨样或软骨样基质;瘤细胞小至中等大小,圆形或梭形,胞质淡嗜酸性,核深染;呈巢状、条索状、梁状、假血管样、微腺泡样排列于粉染硬化基质中,少量球拍样、带状、疟原虫样横纹肌母细胞散在分布于瘤细胞之间,可见横纹。免疫表型:瘤细胞MyoD1弥漫强(+),Desmin局灶逗点样(+),Mygenin局灶弱(+)。结论硬化性横纹肌肉瘤是横纹肌肉瘤的一个罕见亚型,准确诊断依赖组织形态学特征和免疫组化标记。

Objective To investigate the clinicopathologic characteristics and immunochemical feathers of sclerosing rhabdomyo sarcoma(SRMS),in order to improve the diagnosis and differential diagnosis of SRMS.Methods Histopathological and immunohistochemical features of 1 SRMS patient was analyzed,and relative literatures were reviewed.Results The patient was a 28-year-old male,presenting a tumor in right masseter,with a clear border and qualitative hard,sized 3 cm×2.5 cm×2 cm.Histologically,the tumor interstitium was characterized by hyaline degeneration,eosinophilic staining,alike osteoid or cartilaginous matrix.Tumor cells were small to medium size,round or spindle shaped,with lightly eosinophilic cytoplasma and hyperchromatic nuclei,arranged in the powder-stained and hardened matrix in nest,cable,beam,pseudovascular and microacinar patterns.A few racket-like,ribbon pattern or plasmodia-like rhabdomyoblasts were scattered among tumor cells.Immunophenotyping showed the tumor cells were diffuse strong positive for MyoD1,desmin was focal positive,and mygenin was weakly focally positive.Conclusion SRMS is a rare rhabdomyosarcoma.Careful analysis of the histopathological features and immunohistochemisitry will be helpful to reach an accurate diagnosis.