31例老年重症肌无力患者胸腺病变的CT和病理对照研究

Comparative study on thymic lesions of the CT and pathological findings in 31 elderly patients with myasthenia gravis

目的探讨纵隔CT对老年重症肌无力（MG）患者胸腺异常的诊断价值。方法对31例行胸腺切除治疗的老年MG患者的胸部CT和胸腺病理进行对照研究。结果31例MG患者CT诊断胸腺异常23例（74%）,其中胸腺增生7例（23%）,胸腺瘤16例（51%）,正常胸腺8例（26%）;病理诊断胸腺异常29例（94%）;其中胸腺增生17例（55%）,胸腺瘤12例（39%）,正常胸腺2例（6%）。CT诊断胸腺增生7例,异常率为41%,CT诊断胸腺瘤12例,异常率为100%,CT检查与病理检查结果比较,差异有统计学意义（P〈0.05）。CT检查对呈斑点状、索条状胸腺增生易出现漏诊。结论老年MG患者94%有胸腺异常,胸腺瘤占39%,但CT检查对鉴别胸腺增生与正常胸腺及胸腺瘤的价值有限。

Objective To study the computed tomographic（CT） appearance of the thymus in comparison with the results from histologic examination of thymie lesions in elderly patients with myasthenia gravis（MG） who underwent thymeetomy. Methods Thirty-one patients with MG underwent CT examination of the thorax and thymectomy. Results Twenty-three of 31 MG patients had abnormal CT findings （74%）, 7 had lymphoid follicular hyperplasie （23%）, 16 had thymoma （51%） and the remaining 8 had normal thymus（26%）. Twenty-nine patients had abnormal histologie finding （94%）, 17 had lymphoid follicular hyperplasic （55%）, 12 had thymoma （39%） and the remaining 2 had normal thymus （6 %） on histologie examination after thymeetomy. CT showed 41% （7/17） abnormity for lymphoid follicular hyperplasia, and 100% （12/12） abnormity for thymoma. The results of histologie examination was different from CT findings （P 〈 0.05）. The atypical appearances on CT were thymie spots and/or fine line and the diagnosis were easily mistaken on CT scan. Conclusions CT is of limited value in distinguishing lymphoid follicular hyperplasia from a normal thymus or thymoma.