Abstract: CCS is a rare clinical syndrome with unknown etiology and recommended algorithm for diagnosis and treatment has not been available yet. Objective To analyze the epidemiology, clinical characteristics, medical strategy and prognosis of CCS patients from Peiking Union Medical College Hospital. Methods Retrospective analysis, Nonparametric Spearman Correlation analysis to evaluate treatment efficacy and outcomes. Results All CCS cases hadectodermal dysplasia; 4 cases had proteinuria, including 1 case with nephrotic syndrome. The diagnostic sensitivity of CCS was 100% when abdominal pain, diarrhea and positive occult blood were present at the same time. All CCS patients had both upper and lower gastrointestinal polyps, while 40% CCS patients presented with gastric submucosal dark spots. Hyperplastic polyps and gland tubular adenomas were most common pathological patterns. Survival rate was 100% after a median follow-up of 44.7 months. Of 10 CCS patients prescribed with prednisone at the beginning or follow-up, 100% alleviated at different degrees. Restarting treatment with prednisone after withdrawal was still effective when CCS recurrent. Prednisone ≥ 40 mg/day got better prognosis than prednisone < 40 mg/day (n=10, R=-0.655, p＜0.05). Amino salicylic acid medications, hydrotalcid, histamine H2 receptor blockers, proton pump inhibitors, intestinal probiotics, polyps electrocision, or enteral/parenteral nutrition support were not significantly effective; amino salicylic acid medications even correlated to worse prognosis (R = 0.598, p＜0.05). Conclusions Gastric submucosal pigmentation and proteinuria can be seen in CCS patients; systemic strategy based on prednisone therapy get a higher clinical remission rate. The pathogenesis of CCS may involve autoimmune etiology.

Key words: Cronkhite–Canada syndrome, polyp, prednisone, immunity