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肛门旁肿瘤十余天,生长迅速,伴有疼痛。临床诊断肛门脓肿而手术。
您的诊断与鉴别诊断:1、小细胞恶性黑色素瘤。2、横纹肌肉瘤。3、小细胞(神经内分泌癌)4、滑膜肉瘤。5、PNET/EWING肉瘤。6、淋巴瘤。7、淋巴造血系肿瘤。8、其他
小结:
1)本例年轻女性,肿瘤发生在肛旁。是横纹肌肉瘤发生的部位之一;
2)组织学上有腺泡状结构。软组织腺泡状、裂隙状形态的肿瘤,首先要鉴别腺泡状横纹肌肉瘤和腺泡状软组织肉瘤,还有除外血管肉瘤;
3)IHC标记肌源性标志物act+和SMA+,提示肌源性分化。会诊单位标记myogenin+,提示横纹肌起源;
4)Syn+,参阅文献,横纹肌肉瘤可表达Syn阳性;
5)形态学和Syn+,会联系到小细胞癌或促纤维增生小圆细胞肿瘤;但有腺泡状结构和肌源性标志物强阳性不支持小细胞癌;没有小细胞性上皮样岛状结构,而是由腺泡状结构,不是发生在腹腔而是在肛周部位,不支持促纤维增生小圆细胞肿瘤。
腺泡状横纹肌肉瘤,伴有部分神经内分泌免疫表型。
1)根据病人的年龄、病变部位、形态学和IHC标记结果,非常赞成诊断为:腺泡状横纹肌肉瘤。
2)对于Syn阳性的问题比较难解释,可能为1)组织处理问题,2)组织受损伤,3)IHC标记非特异性染色,4)肿瘤细胞异表达。
3)Desmin的强表达更有诊断价值。CD99-除外Ewing/PNET; 上皮性标记-可除外DSRCT;LCA-除外淋巴造血系统来源。
4)IHC增加MyoD1 或Myogenin对鉴别意义并不大。
Base on patient's age, tumor location, HE and immunohistochemistry, this is most likely a case of rhabdomyosarcoma (perhaps alveolar subtype) based on the desmoplastic stroma. The synaptophysin immunoreactivity is difficult to explain, and I would add Cam5.2, CD56, myoD1 and/or myogenin as further immunohistochemical investigation. If Cam5.2 and CD56 are negative, and one (or both) of the two skeletal muscle markers is positive, this would rule out extraosseous Ewing sarcoma or peripheral neuroectodermal tumor and small cell carcinoma, and confirm it is rhabdomyosarcoma. I do not believe this is Merkel cell carcinoma, lymphoma or melanoma.
马老师发言:
本例鉴于患者年龄、肿瘤发生的部位、HE形态和免疫组化标记,有促纤维增生性间质,很可能是横纹肌肉瘤(腺泡型可能)。Syn阳性难以解释。建议增加CAM5.2、CD56、myoD1和/或myogenin,以作进一步免疫组化探讨。要是CAM5.2和CD56阴性,而上述两个骨骼肌标记有1个(或两个)阳性,将除外骨外尤文氏肉瘤或PNET以及小细胞癌,可证明本例是横纹肌肉瘤。本人不认为该例是Merkel 细胞癌、淋巴瘤或黑色素瘤。
Base on patient's age, tumor location, HE and immunohistochemistry, this is most likely a case of rhabdomyosarcoma (perhaps alveolar subtype) based on the desmoplastic stroma. The synaptophysin immunoreactivity is difficult to explain, and I would add Cam5.2, CD56, myoD1 and/or myogenin as further immunohistochemical investigation. If Cam5.2 and CD56 are negative, and one (or both) of the two skeletal muscle markers is positive, this would rule out extraosseous Ewing sarcoma or peripheral neuroectodermal tumor and small cell carcinoma, and confirm it is rhabdomyosarcoma. I do not believe this is Merkel cell carcinoma, lymphoma or melanoma.
聞道有先後,術業有專攻
liguoxia71 离线
小细胞恶性肿瘤。需免疫组化。
鉴别诊断:1、黑色素瘤。2、横纹肌肉瘤。3、小细胞(神经内分泌癌)4、PNET/EWING肉瘤。5、淋巴造血系肿瘤.
qiguaixiaozi 离线