目的分析原发性胸腺癌CT表现 及诊断价值。方法 回顾性分析2015年3月 至2017年3月我院行CT检查的205例胸腺肿 瘤患者的临床病例资料，其中84例经病理 证实为原发性胸腺癌(记为胸腺癌组)， 其余121例为良性胸腺瘤(记为良性组)， 比较两组CT表现的差异，并以病理结果 为准，分析CT对原发性胸腺癌的诊断价 值。结果 84例原发性胸腺癌患者，CT上 可见前上中纵膈肿块影，向一侧或双侧胸 腔凸出，形态不规则或边缘有分叶，密度 不均匀，伴囊变坏死，与邻近结构脂肪层 消失，并侵犯周围组织向远处转移；胸腺 癌组肿瘤直径及不均匀强化、肿瘤不规则 形、纵膈脂肪层消失、心包侵犯、大血管 侵犯、心包积液、淋巴结肿大比例高于良 性组(P＜0.05)；CT诊断原发性胸腺癌的 灵敏度、特异度、准确度、阳性预测值、 阴性预测值、kappa值分别为83.33%、 87.60%、85.85%、82.35%、88.33%、 0.708。结论 原发性胸腺癌CT有典型影像 表现，可依据肿瘤大小、形态、边界、强 化方式等与良性胸腺瘤进行鉴别。

Objective To analyze the findings and diagnostic value of CT for primary thymic carcinoma. Methods The clinical data of 205 patients with thymic carcinomas who underwent CT examination in the hospital from March 2015 to March 2017 were analyzed retrospectively. Among them, 84 cases were confirmed by pathology as primary thymic carcinoma (thymus carcinoma group) and the other 121 cases were benign thymoma (benign group). CT findings of the two groups were compared, and the diagnostic value of CT for primary thymic carcinoma was analyzed based on pathological findings. Results CT findings of 84 patients with primary thymic carcinoma showed anterior upper mediastinal mass shadow, protruding to one side or bilateral pleural cavities, irregular shape or lobulation on edges, uneven density, cystic degeneration and necrosis, adjacent structure fat layer disappearing, invading surrounding tissue with distant metastasis. The ratios of tumor diameter and uneven enhancement, irregular shape, mediastinal fat layer disappearance, pericardial invasion, macro-vascular invasion, pericardial effusion and lymph node enlargement were higher in thymus carcinoma group than in benign group (P<0.05). The sensitivity, specificity, accuracy, positive predictive value, negative predictive value and kappa value of CT in diagnosing primary thymic carcinoma were 83.33%, 87.60%, 85.85%, 82.35%, 88.33% and 0.708, respectively. Conclusion CT findings of primary thymic carcinoma are typical. It can be identified with benign thymoma according to the size, shape, boundary and enhancement mode of tumors.