Adenomatous changes and K-ras codon 12 mutations in colonic polyps of Cronkhite-Canada syndrome

Abstract

Summary. A 68-year-old man was admitted to our hospital with complaints of persisting diarrhea and change in taste sensation. Radiologic and endoscopic examination revealed multiple polypoid lesions in the stomach and colon. Histologic examination of colonic polyps revealed dilated glands in variable sizes containing mucin-producing goblet cells covered by a single layer of columnar epithelial cells anda diagnosis of Cronkhite-Canada (CC) syndrome was made. Also, during a clinical course of CC syndrome, the patient developed idiopathic multicentric osteolysis with acro-osteolysis. CC polyps are generally considered to be inflammatory or nonneoplastic. However, in our patient, 2 CC polyps showed adenomatous changes. By purifying the DNA from adenomatous component of these polyps, we examined the K-ras codon 12 mutation. Both lesions with adenoma showed the K-ras codon 12 mutation, while 1 CC polyp without adenoma did not show any mutation. Although malignant transformation of CC polyps has been considered to be extremely rare, our results indicated the possibility that CC polyps may undergo adenomatous of malignant transformation by alteration of various genes related to colorectal carcinogenesis. Therefore, careful attention should be paid for treating colonic polyps in CC patients.