Bronchioloalveolar carcinoma: focal area of ground-glass attenuation at thin-section CT as an early sign.

Abstract

To assess an early thin-section computed tomographic (CT) finding of the localized formation of bronchioloalveolar carcinoma (BAC). From October 1994 to September 1995, four consecutive patients with biopsy-proved BAC were studied. Thin-section CT (n=4), radiographic (n=4), pathologic (n=4), and positron emission tomographic (n=2) findings were analyzed. Chest radiographs showed focal areas of poorly defined nodules (n=2) and poorly defined opacity (n=2). At thin-section CT, lesions appeared as isolated areas of ground-glass attenuation (n=2) and mixed areas of ground-glass attenuation and consolidation (n=2). The areas of ground-glass attenuation were 1.8-11 cm in longest diameter. A focal, isolated area of ground-glass attenuation changed into mixed areas with consolidation at serial CT in one patient. Mucinous and nonmucinous BACs were observed in two patients each. Positron emission tomography showed false-negative results for malignancy. Focal areas of ground-glass attenuation at CT could be an early sign of localized BAC.