Radiographic differences between two subtypes of bronchioloalveolar carcinoma.

Bronchioloalveolar carcinoma has two light-microscopic, morphologic types, the alveolar type which has cuboidal cells resembling Type II pneumocytes, and the bronchiolar type in which these cells are of the tall columnar variety. To determine if these two different cellular patterns are associated with different clinical or radiologic patterns of disease, we compared the anthropometric, demographic and past medical history, the presenting symptoms, signs, radiographic changes and survival of patients with these two diseases. Clinical records, chest radiographs and pathologic specimens were reviewed by individuals blinded to the hypothesis. Of 30 patients reviewed, we found only one purely alveolar pattern, one predominantly alveolar, 13 mixed, 12 predominantly bronchiolar, and three purely bronchiolar. For analysis we combined the alveolar and the mixed groups and compared them to the purely and predominantly bronchiolar groups. Anthropometric and historical data were similar. The radiographs were different; the most striking difference was the presence of air bronchograms only in the bronchiolar group (p less than 0.0001). Of those who had previous chest films, 80% in the alveolar-mixed group were abnormal, whereas none of those in the bronchiolar group were (p = 0.02). All the initial films in the bronchiolar group had a lesion with definable borders, whereas only two-thirds of the mixed alveolar group did (p = 0.02). Some of the radiographic changes of bronchioloalveolar carcinoma depend on the histologic subtype.