Cronkhite-Canada syndrome containing colon cancer and serrated adenoma lesions

We describe a case of Cronkhite-Canada syndrome associated with sigmoid colon cancer, and provide a literature review. A 77-year-old man was diagnosed with sigmoid colon cancer after presenting with hypoproteinemia, nail atrophy, loss of scalp hair, hyperpigmentation, and gastrointestinal polyposis. The findings were consistent with Cronkhite-Canada syndrome. The colon polyps were histologically serrated adenomas, whose crypts showed a saw-toothed growth pattern with dysplasia, or tubular adenoma. Cronkhite-Canada syndrome associated with colon cancer has been reported in 31 cases. The availability of histologic material permitted reexamination of 25 of these cases. Serrated adenoma of the polypoid lesions was retrospectively found in 10 (40%) of the 25 cases. By comparison, the incidence of serrated adenomas has been estimated to occur in about 1% of all general polyps. Taken together, it is suggested that Cronkhite-Canada syndrome associated with colorectal cancer frequently has polyps containing serrated adenoma lesions. In the case described here, microsatellite instability and overexpression of the p53 protein were found in the cancer lesion and serrated adenoma lesions, and none of the lesions showed a loss of heterozygosity of various genes or K-RAS mutations. Thus, genetic alterations between the serrated adenoma and the colorectal cancer was correlated in this case. These findings suggested the possibility of a serrated adenoma-carcinoma sequence in this case of Cronkhite-Canada syndrome.