Lung Cancer Associated With Cystic Airspaces

Objective This study aimed to define computed tomographic morphologic features of lung cancer associated with cystic airspaces, their modifications in serial computed tomographic scans, and 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography uptake. Methods Computed tomographic scans and 18F-FDG positron emission tomography in 24 patients with lung cancer (17 adenocarcinomas, 7 squamous cell carcinomas, 12 stage I and 12 stage II to IV) associated with cystic airspaces were reviewed. Results Mean diameter of airspace was initially 17.6 mm (range, 5–30 mm), and 4 morphologic patterns were recognized: solid nodule protruding externally (type I, n = 5) or internally (type II, n = 4) from the cyst wall; circumferential thickening of the cyst wall (type III, n = 8); and tissue intermixed within clusters of cysts (type IV, n = 7). With tumor growth, airspace size decreased in 9, increased in 6, and was unchanged in 9 cases. Five cases evolved from type III to type I, and 5 lesions became completely solid. 18F-fluoro-2-deoxy-D-glucose uptake was initially absent to mild in 7 and moderate to marked in 14 lesions. Conclusions Progressive wall thickening or appearance/increase of a nodule inside or outside a cystic airspace should raise suspicion of lung cancer irrespective of FDG uptake.