This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intestinal Polyps, Colon & Anal Cancer, Subject name: Pathology
The highest malignant potential is seen in: 
Select and explain. 
A. Crohn's disease, B. Ulcerative colitis, C. Familial polyposis, D. Infantile polyp
C: Familial polyposis
Answer: C: Familial polyposis 
Explanation: "Colorectal cancer develops in 100% of untreated FAP patients often before the age of 30". Familial adenomatous polyposis (FAP) Autosomal dominant Numerous colorectal adenomas by teenage years. Mutation of adenomatous polyposis coli gene (APC). At least 100 polyps is necessary for diagnosis of classic FAP, High risk of causing colorectal cancer, Prophylactic colectomy is standard therapy Etiology Molecular defect Target gene Transmission Familial adenomatous polyposis APC/WNT pathway APC Autosomal dominant Hereditary nonpolyposis colorectal cancer DNA mismatch repair MSH2, MLH1 Autosomal dominant Sporadic colon cancer APC/WNT pathway APC None Sporadic colon cancer DNA mismatch repair MSH2, MLH1 None