21. Large Bowel Tumours Flashcards
What is a polyp?
Mass arising form mucosal epithelium or submucosa, protruding into the lumen
What are the types of non-neoplastic polyps?
Hyperplastic
Hamartomatous (Juvenile and Peutz-Jehger)
Inflammatory
Lymphoid
What are hyperplastic polyps?
Glands with goblet cells and serrated appearance
Due to delayed shedding of surface epithelium
Very common in people over 60
What are juvenile polyps?
Hamartomatous malformations of bowel mucosa
Dilated glands and inflamed stroma
What are juvenile polyps known as in adults?
Retention polyps
What description is used for Peutz-Jegher polyps?
Christmas tree
What is Peutz Jegher syndrome?
AD
Mucocutaneous pigmentation
Polyps throughout GIT
Increase risk of pancreas, breast, lung, ovary and uterine cancers
What is Cowden syndrome?
AD: mutation in PTEN gene
Multiple hamartomatous polyps and skin tumours
Increased risk of thyroid and breast cancer
What is Cronkhite Canada syndrome?
Hamartomatous polyps
Nail atrophy
Skin pigmentation
What are inflammatory polyps?
Inflamed regenerative mucosa surrrounded by ulcerated tissue
Seen in IBD
What are neoplastic polyps?
Proliferation of dysplastic epithelium
Precursor to carcinoma
Can be tubular, villous (higher risk) or tubulovillous
What are the clinical features of neoplastic polyps?
Asymptomatic
Bleeding, iron deficiency anaemia
Protein loss
Obstruction
What gene is mutated in FAP?
APC gene on 5q21
What is the treatment for FAP?
Remove whole colon as 100% risk of carcinoma in 10-15 years
Name 2 variations of FAP
Gardener’s
Turcot’s