Commonly undergoing malignant transformation is/are

.FAMILIAL ADENOMATOUS POLYP (FAP) is inherited as an autosomal dominant neoplastic condition (chromosome no. 5). * It presents in younger age group--15-20 years. * Incidence is equal in both sex, involving commonly the large intestine but can also occur in stomach, duodenum and small intestine. * It is familial with a high potential for malignant transformation. If there is no adenoma at the age of 30 years, then it is not FAP of colon. * It can be associated with duodenal or ampullary carcinomas , Gardner's syndrome (Desmoid tumour in the abdomen, osteomas (75%) and epidermoid cysts) and also Turcot"s syndrome (FAP + brain tumour (medulloblastoma or gliomas)) or sarcoma of bone. * Usually multiple (over 100). * Presents with lower abdominal pain, loose stools with blood and mucus, weight loss. ref:SRB&;s manual of surgery,ed 3,pg no 838