Bronchioloalveolar carcinoma: clinical, histopathologic, and radiologic findings.

Bronchioloalveolar carcinoma is characterized pathologically by a pulmonary neoplasm showing lepidic growth. More than half of all patients with bronchioloalveolar carcinoma are asymptomatic. The most frequent symptoms and signs are cough, sputum, shortness of breath, weight loss, hemoptysis, and fever. Bronchorrhea is unusual and a late manifestation. Nonmucinous bronchioloalveolar carcinoma tends to be more localized and has a lower frequency of bronchogenic spread than mucinous bronchioloalveolar carcinoma. Bronchioloalveolar carcinoma appears radiographically as a single nodule, segmental or lobar consolidation, or diffuse nodules. At computed tomography (CT), the single nodular form appears as a peripheral nodule or localized ground-glass attenuation with or without consolidation, frequently associated with bubblelike areas of low attenuation and open bronchus signs. The lobar consolidative form may demonstrate the CT angiogram and open bronchus signs. The diffuse nodular form appears as multiple nodules or areas of ground-glass attenuation or consolidation. The single nodular form has a better prognosis than the others but may show false-negative results for malignancy at 2-(fluorine-18) fluoro-2-deoxy-D-glucose positron emission tomography.