Solitary Nodular Bronchioloalveolar Carcinoma of the Lung: Prediction of Histology at High-Resolution CT

Abstract

Purpose : The purpose of this study is to describe the characteristic high-resolution (HR) CT findings of solitary nodular bronchioloalveolar carcinoma (BAC) of the lung which are valuable for specific diagnosis ofthe disease.Materials and Methods : HRCT scans of 46 patients (31 with malignant and 15 with benign lesion) with a solitary pulmonary nodule seen on chest radiograph were distributed in random order and analyzed retrospectively . Two blinded observers jointly analy zed the marginal and internal characteristics of nodules as seen on HRCT, and decisions on the findings were reached by consensus. Stepwise discriminant analysis for characteristic findings ofBAC was performed.Results (5,7,9). Reported CT findings of solitary nodular BAC include a peripheral subpleural location, internal bubble lucency or pseudocavitation, heterogeneous attenuation, irregular margins and pleural tag. These findings are not specific, however, they are frequently observed in adenocarcinoma and large cell carcinoma ofthe lung(lO).In over 70 % of patients, nod ular BAC less than 3 cm in diameter responds to surgery (ll) and when less than 2cm, the reported five-year survival rate is 98. 2 %(3). Early recognition is therefore important. In a recent study involving a small number of patients, we