Bronchioloalveolar adenoma of the lung: CT-pathologic correlation.

PURPOSE: To correlate the appearance of bronchioloalveolar adenoma (BAA) of the lung at computed tomography (CT) with its pathologic features. MATERIALS AND METHODS: Nine small pulmonary nodules with ground-glass attenuation were found at CT in 668 patients with lung carcinoma. Seven of these nine lesions were histopathologically diagnosed as BAA in four patients (three men and one woman, aged 66-77 years) (three lesions in one man, two lesions in the woman, and one lesion each in the remaining two men) and are the subject of this study. RESULTS: BAA of the lung appeared at CT as a small pulmonary nodule with ground-glass attenuation; microscopic examination revealed hyperplasia of the alveolar cuboidal cells on hyperplastic alveolar septa. The CT findings depicted partial reduction of the alveolar air spaces owing to an increase in cellular components within the lesion. Adenocarcinoma cells were also seen within the BAA lesion in one patient. CONCLUSION: In a patient with known lung carcinoma, a small nodule with ground-glass attenuation simulating a focal lesion of pulmonary interstitial disease must be investigated to rule out BAA or multicentric adenocarcinoma.