Pulmonary alveolar microlithiasis (PAM) is an uncommon chronic disease characterized by calcifications within the alveoli and a paucity of symptoms in contrast to the imaging findings.
Pulmonary function tests in this patient showed a restrictive pattern.
The chest radiograph demonstrated a bilateral symmetric micronodular pattern (not shown).
High resolution CT scan revealed diffuse ground-glass attenuation with superimposed septal thickening (crazy-paving pattern).
The patient underwent a lung biopsy, which confirmed the diagnosis of PAM.
PAM needs to be considered in the differential diagnosis of lung lesions that present with crazy-paving pattern on the high resolution CT.