Ulcerative appendicitis in universal and nonuniversal ulcerative colitis.

Ulcerative appendicitis (UA), the appendiceal counterpart of ulcerative colitis (UC), is frequently present in colectomy specimens from patients with universal UC and is regarded as part of the continuous inflammatory process that is a hallmark of this disease. It has been reported, although not universally accepted, that UA may also occur in UC that spares the proximal colon, constituting a skip lesion. Colectomies, which included appendices, from 160 consecutive adult and pediatric patients with UC were reviewed histologically and separated into two groups, universal and nonuniversal UC, on the basis of a stringent histopathological definition of normal mucosa. Forty-five cases with obliterated appendiceal lumens were excluded. UA was present in 82 of the 94 cases of universal UC (87%), including 75 of the 83 adult cases (90%) and 7 of the 11 pediatric cases (64%). UA was present in 18 of the 21 cases of nonuniversal UC (86%), all of which were adults, representing skip lesions. UA was found in 12 of the 14 cases in which colitis commenced distal to the hepatic flexure, including 2 of the 3 cases of left-sided colitis and 2 of the 2 cases of proctosigmoiditis. Among patients whose clinical indication for colectomy was the presence of dysplasia or carcinoma and who had patent appendices, UA was present in 6 of the 9 cases with universal UC (68%) and in each of the 3 cases with nonuniversal UC (100%). We conclude that in colectomy specimens discontinuous appendiceal involvement in nonuniversal UC is as prevalent as continuous involvement in universal UC.(ABSTRACT TRUNCATED AT 250 WORDS)