[Bronchiolo-alveolar carcinoma in a solitary site. The computed tomographic characteristics].

Bronchioloalveolar carcinoma is a peripheral, well-differentiated neoplasm arising beyond a recognizable bronchus, with a tendency to spread to the peripheral air spaces using the lung structure as stroma. This tumor has better prognosis than other lung neoplasms if it is diagnosed early (stage I). For this reason, the CT scans of 16 patients (all of them asymptomatic, only 2 smokers) were reviewed to assess CT capabilities. The cytologic diagnosis was made with CT-guided fine-needle aspiration biopsy in 4 patients (surgical confirmation followed); the histologic diagnosis was made in 12 patients after surgery. CT findings included the peripheral (14 cases) or subpleural (2 cases; 12.5%) location, irregular margins forming a star-like pattern (2 cases; 12.5%), pseudocavitation (13 cases; 81%), heterogeneous attenuation (11 cases; 69%), pleural tags (14 cases; 87.5%) and air bronchogram (2 cases; 12.5%). These CT findings, if compared with the same number of CT scans in patients with adenocarcinoma and squamous cell carcinoma, are present in 70% of patients (11/16) and, although not highly specific (specificity: 36%), they are typical enough to suggest the diagnosis.