Juvenile polyp is a

Ans: b) Hamartomatous polyp ( Ref: Robbins 7th ed / Pg 857 )All four options are non neoplastic (benign) lesions of intestine.Juvenile polyps:Focal hamartomatous malformations involving mucosal epithelium and lamina propriaUsually large rounded glistening lesions with stalks upto 2 cm in length.Usually in children < 5 years of age. Around 80% occurs in rectum.Peutz Jeghers polypsHamartomatous polyps involving mucosal epithelium, lamina propria and muscularis mucosa.Peutz Jeghers syndrome - AD disorder. Multiple polyps throughout GIT, mucocutaneous pigmentation.M/E: Arborizing network of connective tissue and well developed smooth muscle extends into the polyp and surrounds normal abundant glands lined by normal intestinal epithelium rich in goblet cells.- Increased chance of intussusception- No malignant potential of its own, but increased risk of Ca ovary, lung, pancreas, breast, uterus (adenoma malignum), sertoli cell tumors of testes.Bridge:Juvenile polyposis syndrome.AD disorder with risk of adenocarcinoma along with mutations in SMAD4 /DPC4 gene (encoding TGF beta)Mutations of STKII (LKbl ) on chromosome 19.Other hamartomatous polyposis1) Cowden syndromeAD, involving all 3 germ layers.Intestinal hamartomatous, facial trichilemmomas, acral keratosis, oral papillomasIncreased chance of thyroid and breast cancerMutation - PTEN gene on chromosome 10.2) Cronkhite Canada syndromeNm hereditary disorder; idiopathicGI hamartomatous polyps + ectodermal abnormalities (nail atrophy, alopecia)