化生性胸腺瘤2例临床病理观察  

Metaplastic thymoma:a clinicopathologic study of two cases

作　　者：杨静[1] 齐凤杰[1] 

机构地区：[1]辽宁医学院附属第一医院病理科,辽宁锦州121001

出　　处：《诊断病理学杂志》2011年第1期24-26,共3页Chinese Journal of Diagnostic Pathology

摘　　要：目的探讨化生性胸腺瘤的临床病理特征、鉴别诊断及预后。方法对2例化生性胸腺瘤进行光镜观察及免疫组化研究,并复习相关文献。结果 2例化生性胸腺瘤均为女性,年龄分别为52岁和46岁。镜下肿瘤显示双相分化特点,上皮细胞与梭形细胞交错分布并相互移行。上皮细胞呈岛状排列并相互吻合,细胞轻度异型,可见核沟和核内假包涵体;梭形细胞形态温和,呈束状排列;两种类型细胞中均偶见核分裂象。免疫组化:上皮细胞AE1/AE3强(+),EMA灶状(+),vimentin和CD20(-),Ki-67为3%～4%;梭形细胞vimentin弥漫(+),EMA和CgA弱(+),CD20(-);间质淋巴细胞CD3(+),TdT(-)。患者均无重症肌无力。术后无复发和转移。结论化生性胸腺瘤是一类罕见的良性或低度恶性的胸腺肿瘤,其独特的组织学特征及免疫组化有助于诊断和鉴别诊断。Objective To study the clinicopathologic features,differential diagnosis and prognosis of metaplastic thymoma.Methods The microscopic and immunohistochemical features were examined in 2 cases of metaplastic thymoma,with review of related literatures.Results Two patients were female and aged 52 and 46 years respectively.Histologically,the tumors showed a biphasic pattern with epithelial cells merging gradually with spindle cell component.The epithelial cells were arranged in nests and anastomosing cords,mild cytologic atypia,nuclear grooves and pseudonuclear cytoplasmic inclusions were variable.On the other hand,the spindle cells were arranged in fascicles,and showed bland-looking.Few mitotic figures were present in the both cells.Immunohistochemical study showed that the epithelial cells strongly expressed cytokeratin（AE1 /AE3） and focally reactive for EMA,but not for vimentin or CD20.The proliferating index,as demonstrated by Ki-67 immunostaining,was about 3%-4%.In contrast,the spindle cells were diffusely positive for vimentin and faintly positive for EMA and CgA.Staining for CD20 was negative.The background lymphocytes were positive for CD3,not for TdT.None of the patients had myasthenia gravis.All patients were alive without evidence of recurrence or metastasis.Conclusion Metaplastic thymoma is a rarely encountered indolent or low-grade thymic tumor and its differential diagnosis must be established on the histopathological haracteristics and immunohistochemical findings.

关 键 词：胸腺肿瘤 化生性 免疫组化 

分 类 号：R736.3[医药卫生—肿瘤]