Abstract Introduction Organizing pneumonia (OP) is an inflammatory lung disorder characterized by buds of granulation tissue in distal airways and alveolar ducts, typically preserving lung architecture. It can be classified as cryptogenic (COP) or secondary (SOP) when linked to infection, drug reaction, or autoimmune disease. Diagnosis is confirmed by lung biopsy, and patients usually respond dramatically to high dose corticosteroids. Case Presentation A 61-year-old former smoker with occupational exposure to damp, enclosed environments through city steam system work presented with a 3-week history of progressive nonproductive cough, chest tightness, and dyspnea unresponsive to a 5-day course of prednisone. Examination revealed bibasilar crackles with occasional wheeze. CT chest showed diffuse bilateral ground-glass opacities and mediastinal lymphadenopathy (Figure 1). He was admitted to the ICU with acute hypoxic respiratory failure, requiring high-flow nasal cannula. Initial management with antibiotics and Intravenous (IV) steroid for presumed severe community-acquired pneumonia led to partial improvement, but oxygen needs increased after switching reduced dose of oral prednisone. Extensive autoimmune and infectious workup were performed. Transbronchial biopsy confirmed organizing pneumonia with intra-alveolar fibrin and interstitial thickening (Figure 3). High-dose IV steroid was restarted, resulting in significant clinical improvement. Follow-up CT at 3 months showed significant resolution of previous findings. Serologies were positive for Phoma spp.–specific IgG and PL-7 antibodies. Discussion Phoma species are environmental fungi found in soil and water, typically acting as plant pathogens but rarely infecting humans. Reported pulmonary Phoma infections are uncommon and affect immunocompromised hosts. In this case, significant occupational exposure, positive Phoma IgG, and biopsy-proven OP with robust steroid response suggest Phoma-induced secondary OP. Although PL-7 antibody positivity alone does not meet anti-synthetase syndrome criteria, it may represent an immunologic cofactor for invasive fungal disease in an immunocompetent individual. This case underscores the importance of considering environmental and occupational exposures in unexplained OP, recognizing workplace factors as key social determinants of respiratory health. Early identification and preventive strategies are crucial to improve outcomes and reduce recurrence. This abstract is funded by: None
Thapa et al. (Fri,) studied this question.