Abstract
A 45-year-old man presented with malaise, arthralgia, and dyspnea. The chest CT scan showed bilateral patchy consolidation in the lower lobes. A lung biopsy revealed intra-alveolar fibrin "balls" deposits and focal features of organizing pneumonia, both of which are typical pathological features of acute fibrinous and organizing pneumonia (AFOP). The patient had a good clinical course after treatment with prednisone. We report this case of idiopathic AFOP and review the published studies on this newly recognized clinicopathological entity that is still underdiagnosed and underreported.