原发于肺内A型胸腺瘤2例临床病理学观察

Primary pulmonary type A thymoma: a clinicopathological analysis of two cases

目的探讨肺内胸腺瘤的临床病理特征、免疫表型及鉴别诊断。方法分析2例原发于肺内A型胸腺瘤临床病理学特征和影像学资料,并对其行常规病理组织学和免疫组化检查,结合相关文献探讨其临床病理特征。结果男性1例,女性1例,年龄分别为50岁和74岁,影像学检查肿瘤位于右肺上叶及右肺中叶。组织学上肿瘤与周围肺组织边界清楚,瘤细胞排列呈实性片状,无明显的小叶及分割纤维带,缺乏特征性组织学形态,部分区域可见腺样结构及大小不等的微囊形成。肿瘤细胞呈梭形、短梭形及卵圆形,核形温和,染色质散在,无明显核仁,未见核分裂象。间质见极少量淋巴细胞浸润。免疫组化显示肿瘤弥漫性表达CK广谱、EMA和CD20,p53、Ki-67表达率较低。结论肺内A型胸腺瘤是一种极其罕见的肿瘤,临床表现为肺内占位性病变的相关症状或体征,该肿瘤的诊断依赖病理组织学及免疫组织化学检查,预后较好。

Objective To explore the clinical pathological characteristics,the immune phenotype and differential diagnosis of intrapulmonary thymoma. Methods The clinicopathological features and imaging data of 2 cases of primary pulmonary type A thymoma were analyzed,and routine histopathological and immunohistochemical examinations were performed,and the clinicopathological features were discussed in combination with relevant literature. Results One male and one female,aged 50 and 74 years respectively,had tumors in the upper lobe and middle lobe of the right lung.Histologically,the tumor had a clear boundary with the surrounding lung tissue,and the tumor cells were arranged in solid sheets,without obvious lobules and segmented fibrous bands,and without characteristic histological morphology. In some areas,adenoid structures and microcapsules of different sizes could be seen. The tumor cells were fusiform,short fusiform and ovoid,with mild nucleation,scattered chromatin,no obvious nucleoli,and no mitotic figure. Very few lymphocytes infiltrated the stroma. Immunohistochemistry showed diffuse expression of CK,EMA and CD20,and low expression rates of P53 and Ki-67. Conclusions Intrapulmonary thymoma type A is an extremely rare tumor with clinical manifestations of space-occupying lesions in the lung. The diagnosis of this tumor relies on histopathology and immunohistochemical examination,and the prognosis is good.