Two patients who had undergone
proctocolectomy for
ulcerative colitis developed lesions in their ileal stoma that appeared to be inflammatory
polyps morphologically similar to those encountered in the large intestine of
ulcerative colitis patients. One of these patients eventually developed
mucinous adenocarcinoma in the ileal stoma. The ileal mucosa adjacent to the
neoplasm had morphologic features of large-bowel mucosa and was richly populated by
sulfomucin-containing goblet cells, which are characteristic of large-bowel mucosa.
Sulfomucin-containing goblet cells were also found in the inflammatory lesions biopsied from the ileal stomas of both patients, as well as from the
adenocarcinoma found in one patient. These findings support the hypothesis that colonic
metaplasia can occur in ileal stomas of
ulcerative colitis patients. Furthermore, the metaplastic colonic tissue is the site of origin of lesions typically found in
ulcerative colitis. Colonic
metaplasia occurring in ileal stoma should be recognized by pathologists as a clinical entity. When colonic
metaplasia is identified in the ileal stoma of an
ulcerative colitis patient, biopsy surveillance of stomal mucosa is recommended.