Lower GI tumours Flashcards
(53 cards)
Benign tumours of small intestine
- Adenoma
- Mesenchymal tumours (lipoma, angioma, leiomyoma)
Malignant tumours of small intestine
- Adenocarcinomas and carcinoid
- Lymphomas and sarcomas
Benign tumours of colon/rectum
- Non-neoplastic polyps
- Neoplastic-adenoma
Malignant tumours of colon/rectum
- Adenocarcinoma
- Anal zone carcinoma
- Lymphoma
- Leiomyosarcomas
Which part of the small intestine do adenomas usually affect
Ampulla of Vater
Malignant potentiel of small intestine adenomas
Can progress to adenocarcinoma
What do adenocarcinomas look like
- Napkin ring encircling pattern
- Polypoid exophytic masses
Clinical presentation with adenocarcinomas
- Intestinal obstruction
- Cramping pain
- Nausea
- Vomiting/weight loss
- May cause obstructive jaundice
What are the different types of non-neoplastic polyps
- Hyperplastic
- Hamartomatous
What are the different types of neoplastic adenomas
- Tubular
- Villous
- Tubulovillous
Histological features of hyper plastic polyps
- Well-formed glands and crypts
- Lined by non-neoplastic epithelial cells
- Most of which show differentiation into mature goblet or absorptive cells
Macroscopic features of hyper plastic polyps
- Nipple like
- Hemispheric
- Smooth
- Moist protrusions of mucosa
Malignant potentiel of hyperplastic polyps
No malignant potential
Who is affected by hamartomatous polyps
Children younger than 5
Histological features of hamartomatous polyps
- Abundant mystically dilated glands
- Inflammation is common
- Surface may be congested or ulcerated
Malignant potential of hamartomatous polyps
No malignant potential
What are the types of hamartomatous polyps
- Juvenile
- Peutz-Jeghers
Describe Peutz-Jeghers polyps
- Tend to be large and pedunculate
- Do not have malignant potential (but at increased risk of pancreatic, breast, lung and ovarian cancer)
What are the types of adenomas
- Tubular (most common)
- Villous
- Tubulovillous
Why do adenomas arise
Result of epithelial proliferative dysplasia
What features suggest an adenoma may progress to be malignant
- Polyp size (rare in tubular but high risk in sessile villous)
- Histological architecture
- Severity of epithelial dysplasia
Describe small tubular adenomas
Smooth-contoured and sessile
Describe large tubular adenomas
- Coarsely lobulated
- Slender stalks
- Raspberry like
Histological features of tubular adenomas
- Stalk is composed of fibromucular tissue and prominent blood vessels
- Presence of dysplastic epithelium that may show mucin vacuoles
- Carcinomatous invasion into the submucosal stalk of the polyp constitutes invasive adenocarcinoma