肺内淋巴结的临床和影像学特点

Analysis of clinical and radiologic features of intrapulmonary lymph nodes

目的探讨经术后病理证实的肺内淋巴结病例的临床、影像特点，以提高临床诊断率。方法回顾性分析2008年5月至2011年9月，16例手术、病理确诊的肺内淋巴结患者中男9例，女7例；年龄39～73岁，平均58．2岁。术前均行胸部X线平片及高分辨CT检查，单发者11例，多发者3例，另有2例肺癌合并不同肺叶内单发或多发淋巴结的临床、影像学资料。结果全组6例有粉尘接触史或吸烟史，3例来自同一油田区；术前诊断包括肺良性结节、肺癌、肺转移瘤、肺癌肺内转移及性质不明，误诊率56．3％。术前X线胸片发现率50％（8／16例）。肺内淋巴结CT扫描下最大径4～11mm，平均7．1mm，全部位于隆凸以下水平；87．50％（14／16例）为实性结节；68．75％（11／16例）为边界清楚的类圆或卵圆形结节；87．5％（14／16例）距离胸膜1cm以内；87．5％（14／16例）可见线状密度影；2例可见毛刺征；全组未见钙化及纵隔淋巴结病变。术后病理全部淋巴结均可见炭末沉着，8例可见淋巴结增生。结论肺内淋巴结是较为少见的肺内良性结节，临床、影像学表现具有一定特点。对于隆凸以下水平的胸膜下结节，应考虑该诊断可能。

Objective To analysis the clinical radiologic features of intrapulmonary lymph nodes, and to improve the diagnostic rate of intrapulmonary lymph nodes. Methods From May 2008 to September 2011, 16 cases of pulmonary nodules were proved pathologically as intraptdmonary lymph nodes, including 9 males and 7 females, with an average age of 58.2 years （39-73 years）. All patients accepted chest X-ray and HR CT scan prior to operation, identified of 11 solitary nodules, 3 multi- ple nodules, and other 2 cases of multiple nodules with synchronous ipsilateral lung cancer. We retrospectively review the data as follows： the population and clinical characters, the subjective imaging diagnosis, the imaging characters of the nodule loca- tion, size, texture, shape, border, distance from the nearest pleural surface, and the appearance of the surrounding pulmonary parenchyma et al. Results Clinically, six of all the 16 patients are or were cigarette smokers or had an exposure history of in- haled particles, three patients else were all from a same oilfield area although they denied having the Aforementioned history of smoke or exposure. Lung cancer, metastatic tumor, lung cancer intrapulmonary metastasis were the common subjective imaging diagnosis, with a misdiagnosis rate of 56.3 %. Radiologically, these intrapulmonary nodules could be seen in the chest X-ray in half of the 16 patients, with a discovery rate of 50% in chest X- ray screening. The median size of the intrapulmonary lymph nodes was 7.1 mm （4 - 11 mm） , all nodules located below the level of the carina, 87.5% （ 14/16 cases） were solid nodules, 68.75% （ 11/16 cases） were round or ovate in shape with a sharp border. 87.5% （ 14/16 cases） were attached to the pleura or within 1 cm from the nearest pleural surface, 87.5 % （14/16 cases） appeared linear densities extending from the intrapulmo- nary lymph nodes. The linear density referred to the CT imaging feature that a linear soft-tissue density extended from the in- trapulmonary lymph nodes, distinct from the normal lung marking like interlobular septa and bronchovascular bundles, with a diameter less than 5 mm ; spiculation were detected in only 2 of the 16 patients; no calcification and mediestinal lymphadenopa- thy was detect in all the nodules. Pathologically, All nodules contained anthracotic pigment, and follicular hyperplasia were seen in 8 cases. Conclusion Intrapulmonary lymph nodes are rare benign pulmonary nodules possessing certain clinical and radiologic features. Intrapulmonary lymph nodes should be suspected for small subpleural nodules below the level of the carina.