1. FAMILIAL ADENOMATOUS POLYPOSIS
DR.Ammara

2. FAMILIAL ADENOMATOUS POLYPOSIS
Caused by mutations of adenomatous polyposis coli(APC) on chromosome 5q21
FAP can be further classified as
CLASSIC FAP
ATTENUATED FAP
GARDNER SYNDROME
TURCOT SYNDROME

3. NORMAL COLON MUCOSA

4. PEDUNCULATED vs VILLOUS vs SESSILE
A villous pattern of growth, BY GEOMETRY ALONE, implies a faster growth rate than a tubular pattern of growth, hence a greater risk of malignant transformation.

5. ADENOMATOUS POLYP (TUBULAR)
TUBULAR adenoma, note how all the epithelial (glandular) cells look the same.

6. ADENOMATOUS POLYP (VILLOUS)
Villous adenomas behave more aggressively than tubular adenomas. They have a HIGHER rate of developing into frank adenocarcinomas than the “tubular” patterns.
For geometric reasons alone, the VILLOUS pattern of growth is faster than the TUBULAR pattern!

7. ADENOMAS(ADENOMATOUS POLYP)
Tubular,villous.tubulovillous
20-30% before age 40
Have mild to moderate dysplasia
Malignant risk correlates with polyp size architecture and severity of epithelial dysplasia

8. BENIGN vs. MALIGNANT Usual, atypia, pleo-, hyper-, mitoses, etc.
Stalk invasion!!!
What is more important?
How yucky the nuclei look?
If the glands have invaded into the submucosal stalk?

9. Cancer Risk in Polyps

10. Common patterns of familial colorectal neoplasia
FAMILAL ADENOMATOUS POLYPOSIS
70% APC gene autosomal dominant
<10% DNA mismatch repair recessive