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Cronkhite-Canada syndrome (CCS) is characterized by the association of non-hereditary gastrointestinal (GI) polyposis with the cutaneous triad of alopecia, nail changes and hyperpigmentation. To date, approximately 500 cases have been reported: two thirds of these from Japan with the remaining cases involving Caucasians from North America and Western Europe. In Japan, the male to female ratio is 2:1, whereas outside Japan the sex distribution is almost equal. At the time of diagnosis, most patients are over the age of 50, but the age at presentation may vary from 31 to 85 years. Presenting symptoms include watery diarrhea with stool volumes of 4-6 L (steatorrhea and melena may also occur), partial or total lack of taste and appetite, weight loss (often greater than 10 kg), constant or episodic abdominal pain, and weakness. Diarrhea is usually followed by a variable sequence of nail dystrophy (thinning, splitting and color changes), alopecia (initially patchy, rapidly leading to complete hair loss) and hyperpigmentation (diffuse light-to-dark brownish macules and plaques, and patchy vitiligo). GI malabsorption leads to malnutrition, anemia, electrolyte disturbances and hypoproteinemia. More than 10% of CCS patients develop GI (stomach and colon) cancer. Neurologic symptoms (numbness and tingling in the extremities, dysphagia and convulsions) and autoimmune disorders (hypothyroidism and membranous glomerulopathy) have been reported in some patients. The GI changes are usually generalized. The stomach and colon almost always contain polyps and the small bowel is affected in more than 50% of cases. The esophagus is less frequently involved. The pathogenesis of CCS, which is considered to be a member of the group of hamartomatous polyposis syndromes, remains unknown. Altered gut function (digestive, motility, absorptive and secretory), and bacterial overgrowth have been suggested to play a causative role. Unlike many other gastrointestinal polyposis syndromes, familial inheritance has not been described. Diagnosis is based on characteristic clinical and endoscopic findings. Histologically, CCS polyps are characterized by a broad sessile base, an expanded edematous lamina propria, and cystic glands. Differential diagnoses include generalized juvenile polyposis, hyperplastic polyposis, cap polyposis and Peutz-Jeghers syndrome (see these terms), as well as lipomatous polyposis, nodular lymphoid hyperplasia, inflammatory polyposis and lymphomatous polyposis. Management aims at correcting the fluid, electrolyte, and protein loss. Reported treatment modalities include dietary supplementation, antibiotics, corticosteroids, anabolic steroids, acid suppression, cromolyn, administration of zinc, eradication of Helicobacter pylori and combinations of these therapies. None of these therapies has been found to be consistently effective. Most patients need symptomatic treatment for diarrhea and abdominal pain. Due to the generalized nature of CCS and the elevated risk of operative complications, surgery is usually reserved for treatment of complications. Follow-up is required to detect adenomatous lesions that may lead to carcinomas. CCS has a progressive course with a high rate of mortality due to anemia, gastrointestinal bleeding, congestive heart failure or infection. Survival depends on adequate and sometimes prolonged intensive care. Large series have shown that remission occurs in more than one half of the affected patients. Long-term survivors have been reported. |