[An evaluation of the N parameter according to the system of the American Thoracic Society (ATS) in pulmonary carcinoma. A comparison between radiology, surgery and histological diagnosis].

The hilar and mediastinal lymph nodes of 36 patients with bronchogenic carcinoma were evaluated with computed tomography (CT). The American Thoracic Society (ATS) mapping was employed, which defines nodal stations in terms of well-recognized anatomic landmarks which are easily identified with CT and during thoracotomy. The differences (30 cases) between CT and surgical measurements in the 124 nodal stations which could be analyzed are discussed in detail. A better correlation was found using a 2-cm threshold value to define a "positive" or "negative" lymph node with CT. The comparison of radiologic data and the presence of metastases showed how with the 2-cm size criterion sensitivity drops from 81% to 53%, whereas specificity rises from 53% to 84%, thus affecting the subsequent diagnosis and therapy positively.