The development of an elevated lesion associated with colitis cystica profunda in the transverse colonic mucosa during the course of ulcerative colitis: Report of a case

We report the case of a 53-year-old man with a long history of ulcerative c olitis in whom an elevated lesion in the epithelium of the affected transve rse colon was initially diagnosed as a benign inflammatory polyp by endosco pic biopsies. After 4 years of follow-up, because the tumor had enlarged an d villous components were endoscopically observed on the surface, a colonic resection was performed. The tumor was found to consist of hyperplastic co lonic epithelium associated with multiple mucinous cysts lined with dysplas tic colonic epithelial cells. Moreover, the mucinous cysts were primarily l ocated beneath the submucosal layer and appeared to intrude into the muscul aris propria of the colonic wall. This lesion had a unique pathological fea ture, presumably indicating neither benign inflammatory epithelium nor a ne oplastic Lesion of the colonic epithelium. Mucinous cysts lined with coloni c epithelial components in the muscularis propria suggest a loss of normal integrity of the colonic wall. Areas of the epithelial cell lining of the m ucinous cysts showed apparent structural and nuclear atypia and positive ex pression for p53, suggesting that this portion of the specimen was dysplast ic epithelium. These pathological findings may indicate one longitudinal as pect of tumor development which could provide evidence of premalignant chan ge or initial pathological features during the longstanding course of ulcer ative colitis.