Abstract
Two colonic mucoid adenocarcinomas in tamarins from the German Primate Centre are reported. A mucinous mucoid adenocarcinoma occurred in the ascending and transversal colon of a Saguinus oedipus male more than 8 years old, with metastases in the regional lymph nodes and the pancreas. The tumour corresponded to colon cancer in cotton-topped tamarins of other colonies. The second tumour, a well differentiated tubular mucoid adenocarcinoma, developed at the ileocaecal valve of a 14½ year old Saguinus fuscicollis male with metastases to the local lymphatic system.