Localized giant pseudopolyposis of the colon in ulcerative and granulomatous colitis.

The occurrence of localized large clusters of colonic pseudopolyps in 4 patients is described. The underlying disease was chronic ulcerative colitis in 2 cases and granulomatous colitis in 2 others. Each lesion presented as a bulky polypoid mass causing partial or total occlusion of the transverse segment or splenic flexure of the colon. The radiographic and pathologic features of this rare entity are illustrated, and the previously reported 10 cases are briefly reviewed.