In vitro tetraploidy in patients with ulcerative colitis.

One hundred and seven patients (57 patients with ulcerative colitis and 50 controls) were investigated for in vitro tetraploidy (IVT) in dermal fibroblast monolayer cultures. There was no difference in incidence of IVT between patients with ulcerative colitis and controls. We advance the hypothesis that the genetic background of the colorectal cancer type found in ulcerative colitis differs from that found in the colon cancer syndromes and in non-hereditary colorectal cancers. Colorectal cancer in ulcerative colitis is probably only dependent on the degree of inflammatory lesions of the colonic mucosa.