git patho (incomplete, summarised version) Flashcards
what are GIT polyps?
fleshy protuberant growth on epithelial surface
what are the 2 growth patterns of git polyps?
pedunculated, sessile (no stalk)
removal of polyps reduces the likelihood of them developing into…
colon cancer
prognosis for gastric carcinoma depends on…
depth of invasion and extent of nodal and distant metastasis
3 macroscopic (gross) growth patterns of gastric carcinoma evident in both early and advanced stages are:
- exophytic
- flat or depressed (linitis plastica in advanced stages)
- excavated
appearance of a bleeding/chronic peptic ulcer
- flat ulcer edge, level with remaining stomach
- straight vertical edges
- haemorrhagic or flat and clean base
(smth like being hole punched by a hole puncher)
3 gross growth patterns of adenomas are:
- tubular adenoma
- tubulovillous adenoma
- villous adenoma
What are possible causes of upper GIT bleeding? (3 oesophagus, 2 stomach, 2 duodenum and 1 universal!!)
Oesophagitis
Oesophageal varices
Mallory-weiss tear
Gastric erosions
Gastric ulcers
Erosive duodenitis
Duodenal ulcer
Neoplasm
Name 2 kinds of polyps that can form in the stomach:
- Fundic gland polyps
- Hyperplastic polyps
What are the gross appearances of peptic ulcers?
- Round to oval, sharply demarcated, punch-out defect
- Musocal margin may overhang the base slightly
- Variable depth
- Base is smooth and clean
- Scarring and puckering of wall
What are the microscopic appearances of peptic ulcers?
- Surface zone of fibrinopurulent exudate
- Acidophilic layer of necrotic tissue
- Zone of granulation tissue
- Zone of dense scar tissue
- Interruption of muscularis propria
- Proximation of muscularis propria and mucosae
- Endarteritis obliterans
Complication of diverticular diseases?
- Acute inflammation (diverticulitis)
- Pericolic abscesses
- Pericolic fibrosis and adhesions
- Fistulas
- Strictures (can cause obstruction)
- Free perforation into peritoneal cavity - Erosion of blood vessels
- Rectal bleeding
- Anemia
These are rarely malignant.
Generally doesn’t cause diarrhoea
Normal investigations of diarrhoea are:
- Usual stool cultures
- Salmonella
- Campylobacter
- Shigella (requires antibiotics)
- Vibrio (requires antibiotics) - Viral pathogen testing
- Rotavirus antigen detection
- Norovirus PCR
Ischaemic bowel disease is a disease of the…
small intestine where the arterial supply (celiac, superior and inferior mesenteric arteries) are impaired
effects of ischaemic bowel disease
- diarrhoea
- abdominal pain
- bloody diarrhoea (mucosal necrosis»_space; sloughing off and haemorrhage into the lumen)
- less peristalsis (necrosis of muscle)
- peritonitis (transmural necrosis»_space; perforation)
- bacteraemia
Complications of intestinal obstruction
Obstruction of:
1. arterial -> ischaemia
2. venous -> congestion
3. lymphatic -> edema
4. intestinal lumen -> functional
Effects of luminal obstruction:
Vomiting
Distension
Constipation
Pain
Bacterial proliferation
Microscopic appearance of colon adenocarcinoma
- Well/Moderate (90%)/Poorly differentiated degree of tubule formation
- Prominent desmoplastic response
- Abundant intraluminal eosinophilic necrotic debris
- Extracellular mucin pools seen in mucinous subtype of carcinoma
Microscopic appearance of colon adenocarcinoma
- Well/Moderate (90%)/Poorly differentiated degree of tubule formation
- Prominent desmoplastic response
- Abundant intraluminal eosinophilic necrotic debris
- Extracellular mucin pools seen in mucinous subtype of carcinoma
How do people test for linitis plastica?
Pump air into the stomach, inelastic stomachs would denote “leatherbottle appearance”
Adenoma-carcinoma genetic change sequences:
- loss of APC
- DNA hypomethylation
- KRAS activation
- loss of p53
- loss of 18q
- PRL3 amplification
Differences between peptic ulcer and gastric cancer?
Peptic ulcer:
- round to oval, sharply demarcated, punch-out defect
- flat ulcer edge, level with remaining stomach
- haemorrhagic, flat and clean base
- variable depth
- vertical straight edges
- mucosal margin overhang the base slightly
- scarring and puckering of wall
Gastric cancer:
- irregular borders
- not oval, irregular shape
- no punch out defect
- not well demarcated