Colonic polyp with most malignant potential is -

Ans. is 'd' i .e., Sessile Adenomatous poly p o Adenomatous polyps have special clinical significance because only adenomatous polyps are clearly premalignant, and only a minority of these adenomatous lesions ever develop into a cancero Clinically, the probability of an adenomatous polyp becoming a cancer depends on three factors1. Gross appearance of the lesion - on gross appearance polyps are of two typesa. Pedunculated (stalked)b. Sessile (flat based)Cancer develops more frequently in sessile polyps.2. Histologically - Histologically polyps are of 3 typesa. Tubularb. Villous (papillary)c. Tubulovillouso Out of these histological types villous adenomas which are usually sessile become malignant more than 3 times as often as tubular adenomas.3. Size of the polyp -a. Polyp < 1.5 cm ---- Negligible malignant potentialb. Polyp 1.5-2.5 cm ---- Intermediate malignant potentialc. Polyps > 2.5 cm ---- Substantial malignant potential