All the follow. polyps are premalignant except
|A||JuvEnile polyposis syndrome|
|B||Familial polyposis syndrome|
|D||Peutz jegher syndrome|
a. A polyp is a grossly visible protrusion from the mucosal surface and may be classified pathologically as a non neoplastic hamartoma (juvenile polyp), a hyperplastic mucosal proliferation (hyperplastic polyp) or an adenomatous polyp.
b. Only adenomas are clearly premalignant, and only a minority of such lesions ever develop into cancer.
c. Juvenile polyposis syndrome - multiple juvenile polyps in the GIT are present and it carriers a risk of developing adenomas and hence adenocarcinomas. Gene mutation - SMAD4/DPC4.
d. Peutz Jegher syndrome now it is known that it also a risk factor for colonic malignancy.
The malignant risk with an adenomatous polyp is correlated with three interdependant features:
a. Polyp size
b. Histological architecture
c. Severity of epithelial dysplasia