8. Tumours of the Lower GIT Flashcards
Classification of lower GI tumours:
SI: Benign? Malignant?
Colon & rectum: Benign? Malignant?
SI-
Benign: Adenoma, Mesenchymal tumours
Malignant:
Adenocarcinoma & Carcinoid, Lymphomaand Sarcomas
Colon and rectum-
Benign: Non-neoplasticpolyps, Neoplastic-Adenoma
Malignant: Adenocarcinoma(98%), Carcinoid, Anal zone carcinoma, Lymphoma. Leiomyosarcomas
Where is usually affected by adenoma (SI benign tumour)?
Ampulla of vater, becomes enlarged and exhibits a velvety surface
Usual presentation of adenoma of SI benign tumour?
30- to 60-year-old patient with occult blood loss.
Adenocarcinoma (SI malignant tumours)
Usual presentation?
May result in?
Symptoms?
Usual presentation:
– occur in the duodenum, usually in 40- to 70-year-old patients
– napkin-ringencircling pattern
– polypoidexophytic masses
May cause: intestinal obstruction, obstructive jaundice
Symptoms: cramping pain, nausea, vomiting, and weight loss
Examples of benign tumours of the colon and rectum?
Non-neoplastic and neoplastic
• Non-neoplastic polyps:
– Hyperplastic (90%)
– Hamartomatous
• Neoplastic–Adenoma:
– Tubular
– Villous
– Tubulovillous
Hyperplastic polyps: What is it's cancerous classification? Structure? 1/2 found in... Malignant potential? Age incidence?
Benign tumour of the colon and rectum that is non-neoplastic
Structure: Nipple-like, hemispheric, smooth, moist protrusions of the mucosa
1/2 found in rectosigmoid colon
No malignant potential
Found in 60yrs+
Hamartomatous polyps: Juvenile polyps Cancerous classification? What are they? Age? Where are they found? Malignant potential?
Benign tumour of the colon and rectum that is non-neoplastic
What are they?
Malformations of the mucosal epithelium and lamina propria
Age? Less that 5yrs
80% found in rectum
No malignant potential
Hamartomatous polyps: Peutz-jeghers polyps What is it's classification? Associated syndrome? Layers of GIT wall involved? Malignant potential?
Benign tumour of colon and rectum, non-neoplastic
Associated to Peutz-Jeghers autosomal dominant syndrome
Involved the mucosal epithelium, lamina propria, and muscularis mucosa
No malignant potential
• Increased risk of the pancreas, breast, lung, ovary, and uterus carcinoma
Neoplastic polyps (adenomas): Structure? Gender and age incidence Classified into? Arise as result of...
Structure:
- Small, pedunculate lesions
- Large neoplasms that are usually sessile
Gender: Equal
Age: Most after 60yrs
Classifications: Tubular adenomas, villous adenomas, tubulovillous adenomas
Arise as a result of epithelial proliferative dysplasia
Neoplastic polyps- Adenomas:
Precursor for?
Risk is correlated with?
Impossible/possible to determine clinical significance?
denomas are a precursor lesion for invasive colorectal adenocarcinomas
Risk is correlated with:
• Polypsize
• Histological architecture
• Severity of epithelial dysplasia
IMPOSSIBLE from gross inspection of a polyp to determine its clinical significance
Tubular adenomas: Location? Shape? Histology? Clinical features? Treatment?
Location: Colon
Shape: Small = Smooth-contoured and sessile. Large= Coarsely lobulated and have slender stalks raspberry-like
Histology:
- Stalk is composed of fibromuscular tissue and prominent blood vessels
- Dysplastic low grade epithelium
- Carcinomatousinvasioninto the submucosal stalk of the polyp constitutes invasive adenocarcinoma
Clinical features:
- May be asymptomatic
- Evaluation of anaemia or occult bleeding
Treatment: Endoscopic removal of a pedunculate adenoma.
If invasive and sessile polyp further surgery may be required.
BENIGN
Villous adenomas: Age? Location? Shape? Histology? Clinical features? Treatment?
Age: Older persons
Location: Rectum and rectosigmoid
Shape: Sessile, up to 10cm
Histology:
- Frond (1/2 leaf) like villiform extensions of the mucosa
- Covered by dysplastic columnar epithelium
- All degrees of dysplasia present
- When invasive carcinoma occurs, there is no steak as a buffer zone and invasion is directly into the wall of the colon
Clinical features:
- May be asymptomatic
- Evaluation of anaemia or occult bleeding
- More symptomatic than colorectal tubular
- Overt rectal bleeding
Treatment: Endoscopic removal of a pedunculate adenoma.
If invasive and sessile polyp further surgery may be required.
BENIGN
3 conditions to allow tubular and villous adenomas to be removed via endoscope?
Must be a pedunculate adenoma
(1) the adenocarcinoma is superficial and does not approach the margin of excision across the base of the stalk
(2) there is no vascular or lymphatic invasion
(3) the carcinoma is not poorly differentiated
Colorectal carcinoma: Gender? Age? Aetiology? Location? Histology? Clinical features? Classification of lesion?
Gender: Rectum, more men. More proximal tumours, equal.
Age: 60-79
Aetiology:
Dietary factors: Excess calorific intake, lowe veg fibre intake, high content of refined carbs, intake of red meat, decreased intake of protective micronutrients
Location? Mainly rectosigmoid colon
Histology?
- Range from tall, columnar cells to undifferentiated, anapaestic masses
- May produce mucin
Clinical features?
- Asymptomatic for years
- In caecum and right colonic = fatigue, weakness, iron deficiency
- In left side = occult bleeding, changes in bowel habit, cramps in LLQ
- Iron deficiency anaemia in an older male means gastrointestinal cancer until proven otherwise
- Significiant manifestations such as weakness, malaise and weight loss signify more extensive disease
- All colorectal cancers spread. Mainly to liver, lungs and bones.
Classification of lesion by Duke’s stage:
A = Confined to the submucosa or muscle layer. 90% 5yr survival
B= Spread through the muscle layer, but does not yet involve lymph nodes. 70% 5yr survival
C= Involving lymph nodes. 35% 5yr suvival.
In colorectal colon, what is the morphology in the proximal colon?
– Polypoid,exophytic masses
– Obstructionis uncommon
– Penetrate the bowel wall as subserosal and serosal white, firm masses
