Obstructive Colitis Proximal to Partially Obstructive Colonic Carcinoma: A Case Report and Review of the Literature

Background. Obstructive colitis refers to ulceroinflammatory lesions that occur in the colon proximal to an obstructing lesion. As this condition is not widely appreciated by pathologists or clinicians, we describe herein a case of colonic polyposis and sigmoid colonic carcinoma with obstructive colitis. Patient presentation. A 47-year-old Taiwanese woman presented to Cardinal Tien Hospital with a 3 -day history of acute onset of abdominal pain, vomiting, and watery diarrhea. A lower gastrointestinal series using water-soluble contrast medium revealed annular narrowing of the sigmoid colon and showed polyposis at the rectosigmoid colon and regional colitis over the proximal descending colon. She was treated by total colectomy. Microscopic sections showed poorly differentiated adenocarcinoma, tubular adenomas, and a segment of obstructive colitis measuring 25 cm in length 5 cm proximal to the colon tumor. The tumor was also retrieved for simultaneous analyses of replication error and loss of heterozygosity. A total of three instances of loss of heterozygosity were demonstrated at the P53, MET, and D8S254 gene loci. No examples of replication error were detected. Conclusion. Obstructive colitis can cause diagnostic and therapeutic problems. Colitis areas may be a source for septicemia or may perforate and lead to peritonitis. The frequently normal appearance at surgery may lead to involved segments of colon being used for anastomoses with consequent complications. Awareness of the features and incidence of obstructive colitis should help physicians avoid these diagnostic and therapeutic problems.