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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
qiguaixiaozi 离线
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。
Rhabdomyosarcoma (RMS) represents the most common malignant soft tissue tumor in children and adolescents with the urinary bladder representing a frequent site. Most of these urinary bladder tumors are embryonal RMS, predominantly the botryoid subtype. RMSs of the urinary bladder in adults are distinctively rare and the subject of only case reports. We report the clinicopathologic features of 5 bladder neoplasms with rhabdomyosarcomatous differentiation in adults and emphasize the differential diagnosis in the adult setting. The patients, 4 men and 1 woman, ranged in age from 23 to 85 years (mean 65.4 y). Gross hematuria was the most common initial symptom, although 2 patients had metastatic disease at presentation. Four cases were pure primary RMSs of the bladder and 1 case was a sarcomatoid urothelial carcinoma with RMS representing the extensive heterologous component. All 5 cases demonstrated a diffuse growth pattern (ie, non-nested), of which 4 cases had nuclear anaplasia (Wilms criteria without the atypical mitotic figure requirement); only 1 case (the sarcomatoid carcinoma) showed obvious rhabdomyoblastic differentiation (ie, strap cells). Three cases were of the alveolar subtype (1 admixed with embryonal histology) and 2 were RMS, not further classified. Microscopically, all tumors had a primitive undifferentiated morphology with cells containing scant cytoplasm, varying round to fusiform nuclei with even chromatin distribution, and frequent mitoses. The degree of morphologic overlap with small cell carcinoma of the bladder, a relatively more common round cell tumor in adults, was striking. The epithelial component of the sarcomatoid carcinoma was high-grade invasive urothelial carcinoma with glandular differentiation. No other case had previous history of bladder cancer or concurrent carcinoma in situ or invasive urothelial carcinoma. All tumors showed immunohistochemical expression for desmin, myogenin, and/or MyoD1. Synaptophysin was performed in 4 cases, and 3 showed weak cytoplasmic immunoreactivity. Two patients received chemotherapy, 2 underwent cystectomy, and 1 had transurethral resection alone. Outcome data were available in 4 cases, and all 4 died of disease (1, 4, 8, and 8 mo). In conclusion, (1) RMS of the urinary bladder in adults more commonly presents as a primitive round blue cell neoplasm that has significant morphologic and immunohistochemical overlap with small cell carcinoma of the bladder. (2) Although RMS in children generally have a botryoid embryonal histology with favorable outcome, bladder RMS in adults frequently demonstrates alveolar or unclassified histology, commonly with anaplasia, and have a uniformly aggressive clinical course.
文中Syn为弱阳性,而此例是明显的阳性,另一篇文献中没有提到其阳性强度如何,一般而言,Syn的特异性还是不错的,至少不比desmin差吧。对于这样的病例,传统的病理学辅助手段很难再有说服力,可能只能靠遗传学及超微病理检查了。
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.
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.
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.
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。