A case report of fungal infection associated acute fibrinous and organizing pneumonitis

Abstract

Abstract Background Acute fibrinous and organizing pneumonitis (AFOP) is an uncommon variant of acute lung injury, characterized by intra-alveolar fibrin and organizing pneumonia. Proposed etiologies include connective tissue diseases, infections, occupational exposure, drug reactions, and autoimmune disease. Here we present a rare case of fungal infection associated AFOP in patient with diabetes mellitus (DM) and review the relevant literature. Case presentation A 67-year-old man complained of cough, fever, dyspnea and hemoptysis. Patient experienced a rapidly progressive course exhibit diffuse predominant consolidation, ground glass opacities, and multifocal parenchymal abnormalities on chest computed tomography (CT). Antibacterial, antifungal, and antiviral treatments were ineffective. A CT-guided percutaneous lung biopsy was performed. Histologically, the predominant findings were as follows: alveolar spaces filled with fibrin and organizing loose connective tissues involving 70% of the observed region, pulmonary interstitial fibrosis, and small abscesses and epithelioid cell granuloma in the focal area. Result of periodic acid-silver methenamine stain was positive. The fungal pathogen from the sputum culture was identified as P. citrinum repeatedly over 3 times. Patient was diagnosed with DM during hospitalization. Corticosteroids combined with an antifungal therapy were effective. Follow-up for 4 months showed complete radiological resolution. Conclusions As this common “contaminant” can behave as a pathogen in the immunocompromised host, both clinicians and microbiologists should consider the presence of a serious and potentially fatal fungal infection on isolation of P. citrinum. Based on this case, it could be speculated that AFOP may be associated with fungal infection including P. citrinum.