不典型A型胸腺瘤临床病理分析  

Clinicopathologic features of atypical type A thymoma

作　　者：苏运超[1] 底锦熙[1] 笪冀平[1] 

机构地区：[1]中日友好医院病理科,北京100029

出　　处：《中华病理学杂志》2017年第5期314-317,共4页Chinese Journal of Pathology

摘　　要：目的 探讨不典型A型胸腺瘤的临床病理特点、免疫组织化学表型及鉴别诊断.方法收集2004至2016年3例不典型A型胸腺瘤的临床病理资料及随访资料,进行光镜观察及免疫组织化学染色,并对相关文献进行复习.结果 3例患者均为男性,平均年龄59岁.临床表现均为前纵隔肿物.肿瘤最大径4~6 cm,部分有包膜,切面灰白-灰褐色,多结节状,质地均匀细腻,可见囊性变及坏死.组织学以单一短梭形、卵圆形细胞为主,片状、席纹状或旋涡状排列,可见微囊、腺样结构、rosettes结构及血管外皮瘤样结构.肿瘤细胞丰富,轻度异型,核分裂象（4~5）/10 HPF,均可见坏死.免疫组织化学染色,肿瘤性上皮呈现广谱细胞角蛋白（CKpan,AE1/AE3）、CK19、p63、波形蛋白弥漫强阳性,上皮细胞膜抗原局灶阳性,主要表达在腺样结构的腔缘,CK20、CD20、CD5、CD117均阴性;间质淋巴细胞主要表达CD3及CD5,CD20个别阳性,末端脱氧核苷酸转移酶（TdT）阴性;肿瘤细胞Ki-67阳性指数为15.2%~26.4%.3例患者术后随访9~27个月,均无复发或转移.结论 不典型A型胸腺瘤是A型胸腺瘤的一个亚型,具有一定的不典型性,如坏死、核分裂象增多、增殖指数增高等,这些组织学改变与其生物学行为的关系仍需进一步研究.Objective To study the clinicopathologic features, immunophenotype and differential diagnosis of atypical type A thymoma.Methods Clinicopathologic and follow-up data of three cases of atypical type A thymoma from 2004 to 2016 were reviewed. Immunohistochemical staining was performed. Results All three patients were male with average age of 59 years. Clinically, the lesions presented as anterior mediastinal masses. Grossly, the tumor ranged in size from 4 to 6 cm in greatest dimension and partially enclosed within fibrous capsule. The cut surface was homogenously fleshy, tan to brown in color, with multinodular and lobulated configurations. Cystic changes and necrosis were seen. Microscopically, the tumor was composed of plump spindle or oval-shaped cells arranged in storiform, microcystic, glandular, rosettes-like and hemangiopericytoma-like histological patterns. The tumor cells showed mild cytological atypia and mitotic activity ranged from 4 to 5/10HPF. Necrosis was present in all tumors. All tumors showed diffuse CK（AE1/AE3）, CK19, p63 and vimentin expression. TdT, CK20, CD20, CD5 and CD117 were negative. The proliferative index, as measured with Ki-67, was 15.2% to 26.4%. None of the cases had recurrence or metastases during the follow-up period （9 to 27 months）. Conclusions Atypical type A thymoma presents atypical features including tumor necrosis and increased mitotic activity. However, the implications of such atypical features to the biological behavior of the tumor remain to be determined..

关 键 词：胸腺瘤 诊断 鉴别 不典型 

分 类 号：R736.3[医药卫生—肿瘤]