Pulmonary necrobiotic nodules in Crohn's disease: a rare extra-intestinal manifestation.

Pulmonary necrobiotic nodules represent a rare extra-intestinal manifestation of Crohn's disease. Histologically, they are composed of sterile aggregates of inflammatory cells with necrosis. The differential diagnosis is broad, and exclusion of infectious etiologies is mandatory before starting immunosuppressive therapy. Here, we present the fifth reported case of pulmonary necrobiotic nodules in Crohn's disease. Our patient had new-onset Crohn's disease associated with both cavitating and non-cavitating lung nodules that were confirmed to be necrobiotic nodules by biopsy. The patient was started on mesalamine and prednisone, with subsequent improvement of his gastrointestinal symptoms and regression of the necrobiotic nodules.