RESUMO
BACKGROUND: Acute fibrinous and organizing pneumonia (AFOP) is a very rare form of acute or subacute lung injury, which is characterized by patches of "fibrin balls" distributed within the alveoli. Given the lack of typical clinical manifestations, AFOP is often misdiagnosed as pneumonia, tuberculosis, etc. Definitive diagnosis is obtained from a lung biopsy. Corticosteroids are usually effective. CASE PRESENTATION: We report two cases of patients with histopathological manifestations of AFOP, which were significantly improved after corticosteroid therapy. Previous reports of the clinical and pathological characteristics of AFOP were reviewed to improve clinicians' understanding of this disease. CONCLUSIONS: Early identification and diagnosis are very important for AFOP treatment. The prognosis is acceptable after timely and effective treatment.