A rare pulmonary manifestation of Crohn's disease: Acute fibrinous and organizing pneumonia presenting as multifocal nodules.

Acute Fibrinous and Organizing Pneumonia (AFOP) is a rare pulmonary disease, and it has not been recorded in literature as a pulmonary manifestation of Crohn's disease. A 22-year-old individual with an extensive history of Crohn's disease presented to the hospital initially for hematochezia and diarrhea. Computed tomography of her abdomen and pelvis showed multiple pulmonary nodules bilaterally. The patient did not report cough, sputum production, or dyspnea. Autoimmune and infectious workup were overall unremarkable. A CT-guided percutaneous biopsy of a peripheral lung nodule was performed showing features consistent with AFOP. The patient was ultimately treated with a long taper of prednisone and Ustekinumab for Crohn's disease. Follow-up CT-chest showed interval reduction and improvement in lung nodules, which correlated with better control of the patient's Crohn's disease. Pulmonary manifestations of IBD are varied, including pleural disease, bronchiectasis, and organizing pneumonia. Bronchiolitis obliterans organizing pneumonia has been described more frequently in patients with ulcerative colitis compared to Crohn's. Pulmonary nodules are a rare manifestation of IBD and often tend to be granulomatous or necrobiotic. AFOP is a rare entity with no previously reported association with IBD. Secondary AFOP can be caused by autoimmune diseases, drug reactions, infections, or radiation. Treatment of AFOP is usually immunosuppression by glucocorticoids.