An unusual perilobular pattern of pulmonary interstitial fibrosis associated with Crohn's disease

Pulmonary pathology associated with inflammatory bowel disease is rare, and seldom biopsied. In this report, we describe a case of pulmonary interstitial fibrosis associated with Crohn's disease. Biopsy showed a unique pattern, with cellular fibroblastic proliferation and fibrosis affecting interlobular septa, spreading into the parenchymal interstitium from the periphery, with associated lymphoid aggregates and thickening of arterial adventitia.