The pathology of Yersinia enterocolitica ileocolitis.

The terminal ileum and proximal colon were resected in two children presenting with fever and right lower quadrant abdominal pain. The pathological findings were characteristic; elongated ulcerations with underlying lymphoid hyperplasia involved the distal ileum and smaller punctate aphthoid ulcers involved the distal ileum and colon. Transmural inflammation was seen in both cases and resulted in thickened, erythematous distal ileum mistaken at surgery for Crohn's disease. Yersinia enterocolitica was recovered from operative cultures of both the specimens. One of the two patients had a 1:1280 serological titer for Yersinia enterocolitica 1 week after surgery. The pathologic findings of Yersinia enterocolitica ileocolitis are distinctive and easily differentiated from Crohn's disease and other pathologic processes in this region. Operative diagnosis can be difficult but if the possibility of Yersinia infection is considered, the correct diagnosis can usually be made without unnecessary surgical resection.