Reclassification of Cystic Bronchioloalveolar Carcinomas to Adenocarcinomas Based on the Revised World Health Organization Classification of Lung and Pleural Tumours

The objective of this study was to evaluate the radiologic–pathologic correlation of cystic change in cases of bronchioloalveolar carcinoma (BAC) using the 1999 revised World Health Organization Classification of Lung and Pleural Tumours. A total of 304 cases diagnosed as BAC before 1999 were reviewed retrospectively for radiologic findings of cystic change (n = 31). Of these, 20 had adequate clinical, pathologic, and radiologic material available for review. Patient demographics and history; the method, location, and size of specimen biopsy; and pathology reports were evaluated. A pulmonary pathologist reviewed the microscopic findings to confirm the diagnosis based on the 1999 World Health Organization criteria. Chest radiographs (n = 20) and computed tomographic scans (n = 11) were analyzed for location, size, and multiplicity of pulmonary nodules, masses, consolidations, or characterization of cystic change. Associated findings of lymphadenopathy, pleural effusion, atelectasis, and underlying lung disease were noted. There were 10 men and 10 women (mean age, 49.3 years) who participated in the study. Eleven were symptomatic. Pathologic review, based on the revised World Health Organization classification, yielded the diagnosis of adenocarcinoma (n = 14); adenocarcinoma, possible BAC (n = 4); and BAC (n = 2). Radiologically, adenocarcinoma (n = 14) manifested as a solitary pulmonary nodule/mass (n = 5) or consolidation (n = 6) and as multifocal mixed disease (n = 3) with solitary (n = 8) or multicystic (n = 6) change. Adenocarcinoma, possible BAC (n = 4) manifested as multifocal and multicystic consolidations (n = 2) or mixed disease (n = 1) and as a solitary cystic mass (n = 1). BAC (n = 2) manifested as a cystic mass (n = 1) and as multifocal multicystic mixed disease (n = 1). Most cases of BAC with radiologic cystic change were reclassified as adenocarcinoma. The radiologic features of BAC may need to be redefined in light of the current diagnostic criteria to help identify patients with limited and potentially curable disease.