Chest Radiographic Findings of Missed Lung Cancers

To assess the failure of detection of lung cancer at chest radiography. From 2002 to 2003, we collected 37 cases of lung cancer that were initially undetected but were diagnosed retrospectively at chest radiography. Of these 37 cases, 17 were adenocarcinoma, 15 were squamous cell carcinoma and the other 5 were non-small cell carcinoma. Size, locations, and patterns of the missed tumors as well as the superimposed structures at chest radiography were reviewed. Lung cancers were missed at chest radiography in 37 of 685 (5.3%) patients, of whom 28 (76%) were men and 9 (24%) were women. The median patient age was 71 years. The mean diameter of the missed cancers was 2.1cm. Most of the missed cancers (81%) were centrally located. In respects of lobar distribution of the missed lesions, 46% of the lesion was in the upper lobe, 38% in the lower lobe and 16% in the middle lobe. The majority of the missed cancers presented either as a nodular, ill-defined, or hypodense lesion. In all our 37 cases, the lesions were obscured at least in part by the superimposed structures, particularly the ribs and pulmonary vessels. Well recognition of the characteristics of missed lung cancer may help in the way of tumor detection.