Squamous Cell Carcinoma of the Lung Spreading Along the Alveolar Walls With a Bubblelike Appearance on HRCT.

On health examination, a nodular opacity of size of 25 mm was detected in a 54-year-old man. High-resolution computed tomography scans showed irregular-shaped ground glass opacity with bubble-like appearance in the right lung. The low-magnified histological findings after right upper lobectomy demonstrated squamous cell carcinoma that progressed along the alveolar septum and resembled the growing pattern of bronchioloalveolar carcinoma. As the mechanism of the formation of air density on computed tomography, the presence of check valve phenomenon was estimated. Squamous cell carcinoma of the lung that multiplies along alveolar walls shows localized ground glass opacity including air density areas similar to those in bronchioloalveolar carcinoma on high-resolution computed tomography.