Findings

This is a segment of the ileum. The intestinal wall is markedly thickened due to inflammation, edema, and fibrosis. This results in narrowing of the intestinal lumen. Note also the granular appearance of the mucosa which normally is smooth with circular folds at regular intervals. These changes involve the intestine segmentally ("skip lesions"), leaving uninvolved segments.

Impression

Ileum, Crohn's disease

Pathology Pointer

Crohn's disease is characterized by transmural injury and inflammation which occur segmentally (i.e. areas of involvement called "skip lesions" are separated by unaffected tissue). Note also the serosal extension of mesenteric fat ("creeping fat"). Crohn's disease may occur anywhere in the GI tract, but it usually involves the distal small bowel or colon, or both.

Preparation

Fresh

View

Gross photograph

Specimen

Ileum

Image Credit

Katsumi M. Miyai, M.D., Ph.D
Department of Pathology
School of Medicine
University of California, San Diego