Crohn's disease with pulmonary involvement in a 3 year old boy.

Extra-intestinal or metastatic Crohn's disease is being recognised increasingly, most commonly in the skin and genitourinary system. Only very rarely has it been reported in the lung. A 3 year old boy who presented with swollen gums and a persistent abnormality on his chest x ray is reported. Lung biopsy specimens showed multiple non-caseating epithelioid granulomas. Subsequent investigation showed the presence of intestinal Crohn's disease. The evidence for abnormal lung function in Crohn's disease and the possible pathogenesis of metastatic pulmonary Crohn's disease are discussed.