A case report: Acute fibrinous and organizing pneumonia

RATIONALE: Acute fibrinous and organizing pneumonia (AFOP) is a rare acute or subacute interstitial lung disorder characterized by the deposition of fibrin within the alveoli and organizing pneumonia with a patchy distribution. The clinical features of AFOP are nonspecific, and it is often misdiagnosed as pneumonia, cancer, tuberculosis, or other lung disorders. PATIENT CONCERNS: In this case report, a 58-year-old woman presented with chest tightness, shortness of breath, cough and sputum. A chest CT scan showed multiple patchy shadows in both lungs. She was initially diagnosed with community-acquired pneumonia. Her purified protein derivative skin test was positive, but sputum was negative for acid-fast bacilli. DIAGNOSES: AFOP was diagnosed by bronchoscopic lung biopsy and histopathology. INTERVENTIONS: Following AFOP diagnosis, all anti-infective drugs were discontinued, and replaced by methylprednisolone and prednisone. OUTCOMES: After 1 week of treatment with methylprednisolone 40 mg daily, the patient chest CT and clinical symptoms improved. After 1 month, the patient symptoms had demonstrated dramatic improvement and CT scan revealed complete absorption of lesions in both lungs. After 5 months of follow-up, the patient symptoms completely disappeared. LESSONS: Acute AFOP is an uncommon lung condition with poor prognosis; hence, early diagnosis and identification are particularly important. Definitive diagnosis requires histopathological findings. Currently, there is no unified treatment guideline for AFOP, and treatment must be tailored based on the etiology and severity of each individual patient disease. Subacute AFOP shows a good response to corticosteroid treatment.