CXR is normal at presentation in up to 6% of symptomatic patients. Hilar or mediastinal lymphadenopathy is rare, as is pleural fluid in the absence of extrapulmonary pneumocystosis.

In practice, the disease affects both airways and interstitium. Normal CT is good evidence that PCP is not the cause of symptoms. 

One third of patients with PCP develop pneumatocoeles, with predilection for upper lobes, especially in patients treated with aerosolized pentamidine. Spontaneous pneumothorax is a complication.