Figure 8c. PLCH in an 18-year-old woman with chronic cough and no known history of cigarette smoking. (a, b) Posteroanterior (a) and posteroanterior collimated (b) radiographs show subtle, bilateral reticular and nodular areas of opacity that predominantly affect the middle and upper lung zones and spare the lung bases. (c-d) Targeted unenhanced high-resolution CT scans (lung window) of the upper (c), middle (d), and lower right (e) lung show irregular nodules as well as thin- and thick-walled cysts. The profusion of abnormalities is greatest in the upper lung and progressively decreases in the middle and lower lung zones.