胸腺上皮性肿瘤52例的临床病理分析

Clinicopathoiogic analysis of 52 cases of thymic epithelial tumor

目的探讨胸腺上皮性肿瘤的临床病理学特点，评价2004年WHO胸腺肿瘤分类的可重复性及其临床意义。方法收集2001年1月至2009年6月间52例胸腺上皮性肿瘤的资料，对其形态学特征和免疫表型进行回顾性复习，按照2004年WHO胸腺肿瘤分类进行组织学分型，并对临床资料加以分析和总结。结果胸腺瘤45例，胸腺癌7例。胸腺瘤中以AB型最多见，占33．3％（15／45），其次为B2型和B3型，均为20．0％（9／45）。A型和B1型相对少见，分别占13．4％（6／45）和8．9％（4／45）。另有2例化生性胸腺瘤（4．4％）。7例胸腺癌中6例为鳞状细胞癌分化，1例为神经内分泌癌。临床上，多数患者因咳嗽或胸痛就诊，部分病例为体检中偶然发现。胸腺瘤中13例伴有重症肌无力（25．0％）。影像学上，49例（94．2％）位于前纵隔，其中A、AB、B1和多数B2型胸腺瘤表现为边缘光整、密度均匀的肿块，少数B2型、多数B3型胸腺瘤和胸腺癌表现为边界欠清、外形不规则和密度不均的肿块。48例手术Masaoka分期为：Ⅰ期20例（41．7％），Ⅱ期15例（31．3％），Ⅲ期11例（22．9％），Ⅳ期2例（4．1％）。分析显示，组织学分型与临床分期有显著相关性（X^2=32．5，P〈0．01）。结论基于细胞形态、功能和遗传学的2004年WHO胸腺肿瘤分类具有较高的可重复性，并在一定程度上反映胸腺瘤各亚型的生物学行为，对临床治疗和预后判断有指导意义。

Objective To study the clinicopathologic characteristics of thymic epithelial tumors and to evaluate the diagnostic reproducibility and clinical relevance of the 2004 WHO histologic classification system. Methods The morphology and immunophenotype of 52 cases of thymic epithelial tumor were reviewed. The tumors were classified according to the new WHO classification system and the clinical data were analyzed. Results Of the 52 cases studied, 45 were thymomas and 7 were thymic carcinomas. Amongst the 45 cases of thymoma, 6 （13.4%） were type A, 15 （33. 3% ） were type AB, 4 （8.9%） were type B1, 9 （20. 0% ） were type B2, 9 （20.0%） were type B3 and 2 （4.4%） were metaplastic thymoma. Amongst the 7 cases of thymic carcinoma, 6 were squamous cell carcinomas and 1 was neuroendocrine carcinoma. The commonest presentations were cough and chest pain. Some cases were incidentally discovered by routine physical examination. Thirteen cases （25. 0% ） of thymoma were associated with myasthenia gravis. CT scan showed that 49 cases （94. 2% ） were located in the anterior mediastinum. All cases of type A, AB and B1 thymoma and most cases of B2 thymoma appeared as well-defined homogeneous mass, whereas a few cases of type B2 thymoma and most cases of type B3 thymoma and thymic carcinoma were poorly demarcated and heterogeneous. According to Masaoka staging system, 20 cases （41.7%） belonged to stage Ⅰ , 15 cases （31.3%） stage Ⅱ, 11 cases （22. 9% ） stage Ⅲ and2 cases （4. 1% ） stage Ⅳ. The histologic subtypes of thymic epithelial tumors significantly correlated with the clinical stages （ X^2 = 32. 5, P 〈 0. 01 ）. Conclusions The 2004 revision of WHO histologic classification system for thymic epithelial tumors shows a high degree of reproducibility. Correlation with the radiologic, clinical and prognostic parameters is helpful in determining the management strategy for individual patients.