<prompt> . The highest malignant potential is seen in -Crohns diseaseUlcerative colitisFamilial polyposisInfantile polyp  <response>: The malignant potential of familial polyposis coli is very high. Colorectal cancer develops viually in 100 of cases by age of 50 years if not treated with colectomy. TEXTBOOK OF PATHOLOGY 6TH EDITION HARSH MOHAN PAGE NO:585 