Cronkhite-Canada syndrome associated with colon carcinoma and adenomatous changes in C-C polyps.

A 73-yr-old man with the clinical features of Cronkhite-Canada syndrome developed colonic carcinoma. Radiologic and endoscopic examination revealed numerous polyps involving the stomach and large intestine. Histologic examination of the biopsied polyps revealed polypoidal lesions covered by a single layer of normal columnar mucus-secreting epithelial cells. The stroma of each polyp was composed of well-vascularized edematous lamina propria containing inflammatory cells and glands of variable sizes. Some of the glands were cystically dilated and lined by a single layer of mucin-secreting epithelial cells. These polyps were reminiscent of "juvenile polyps" or retention polyps. Some of these polyps also showed definite adenomatous changes at the surface epithelium. In addition, a large cecal tubulovillous adenoma with foci of well-differentiated adenocarcinoma was noted, indicating that adenomatous and carcinomatous epithelial changes can occur in otherwise nonneoplastic polyposis of the Cronkhite-Canada syndrome as seen in the present case.