纵隔AB型胸腺瘤的CT特征

CT features of mediastinal type AB thymoma

目的:总结纵隔AB型胸腺瘤的CT特征,以提高对该病的认识,避免误、漏诊。方法:回顾性分析11例经手术病理证实的纵隔AB型胸腺瘤患者的临床表现及CT资料,观察病灶部位、大小、数目及密度等。结果:11例均为单发,病灶呈类圆形9例,不规则形2例。前纵隔9例,其中位于正中3例,右侧2例,左侧4例;右侧纵隔1例;右下后纵隔1例。病灶最大径28~104 mm,平均(58.0±2.5)mm,中位最大径51 mm。11例中,8例CT平扫表现为软组织密度影,4例密度均匀,4例密度不均匀;3例伴钙化。增强扫描9例中5例呈明显不均匀结节样强化,病灶内见线状低密度分隔;1例呈中度不均匀强化;3例呈明显均匀强化。10例边界清楚,周围结构均无异常;1例与邻近胸膜分界不清。结论:纵隔AB型胸腺瘤具有一定的特征性,CT平扫多表现为软组织密度影,增强扫描呈多个明显不均匀强化结节,病灶内见低密度分隔。

Objective:To summarize the CT features of type AB thymoma of mediastinum in order to improve the understanding of the disease and avoid misdiagnosis and missed diagnosis.Methods:The clinical manifestations and CT data of 11 patients with type AB thymoma confirmed by operation and pathology were analyzed retrospectively.The location,size,number and density of lesions were observed.Results:Among the 11 cases,the lesions were solitary,quasi-round in 9 cases,irregular in 2 cases.There were 9 cases of anterior mediastinum,including 3 lesions in the center,2 lesions on the right and 4 lesions on the left.There was 1 case of right mediastinum and 1 case of right lower posterior mediastinum.The maximum diameter of the lesions was 28~104 mm,average of(58.0±2.5)mm,and the median maximum diameter was 51 mm.Of the 11 lesions,8 lesions showed soft tissue density on CT,4 lesions had homogeneous density,4 lesions had inhomogeneous density,3 lesions were associated with calcification.Of the 9 cases with enhancement scan,5 lesions had obvious inhomogeneous nodular enhancement and linear low density separation,1 lesion had moderate inhomogeneous enhancement,and 3 lesions had obvious homogeneous enhancement.The boundary was clear in 10 cases and the surrounding structure was not abnormal,while in 1 case,the boundary was not clear and the boundary with the adjacent pleura was not clear.Conclusions:Type AB thymoma has certain characteristics,and the plain scan of CT is not specific,and the enhanced scan shows several obviously inhomogeneous enhanced nodules.The diagnosis of type AB thymoma should be considered when there is low density septum in the focus.