Histopathology 16: Lower GI Flashcards
(37 cards)
A 2 year old boy with down syndrome presents with symptoms of constipation with overflow diarrhoea and vomiting. There are signs of abdominal distension.
What is the most likely diagnosis ?
Hirschsprung’s disease
Where does Volvulus tend to occur in children? Where does it occur in adults ?
Children= small bowel Adults = Sigmoid colon
Which organism causes pseudomembranous colitis ?
C.difficile
antibiotics kill commensal bacteria and allow C.diff to flourish. It’s endotoxins cause Pseudomembranous colitis
List features of Crohn’s disease ?
- ENTIRE GIT affected (mainly terminal ileum and large bowel)
- Transmural inflammation (all the way through the wall)
- Skip lesions
- Non-caseating granulomas
- Cobblestone mucosa
- Can affect anus to mouth
- Fistula formation
Extra-intestinal (NB also get these in UC):
- Arthritis
- Uveitis
- Stomatitis/ cheilitis
- Skin lesions: erythema multiforme, nodosum
List 5 features of Ulcerative colitis ?
- Involves rectum and Colon but not small bowel
- Inflammation confined to the mucosa (NOT transmural like Crohn’s)
- Inflammation is continuous, no skip lesions
- Backwash ileitis- terminal ileum gets involved
- Can cause toxic megacolon
- ULCERS
- mucosa regenerates forming pseudopolyps
- Crypt abscesses
List 3 skin lesions seen in Crohn’s ?
Erythema multiforme
Erythema nodosum
Pyoderma gangrenosum
List 3 familial syndromes characterised by polyps ?
Familial adenomatous polyposis
Peutz-jeghers syndrome
Hereditary non polyposis colorectal cancer (HNPCC)
Name 2 subtypes of FAP ?
Gardner’s syndrome
Turcot syndrome
List 5 extra-intestinal manifestations of Gardner’s syndrome ?
Gardner’s syndrome: pathological and aetiological features of FAP with a high cancer risk
- Multiple Osteomas of the skull and mandible
- Epidermal cysts
- Desmoid tumours
- Dental carries/ unerrupted supernumerary teeth
- Post surgical mesenteric fibromatoses
List 3 features seen in carcinoid syndrome ?
- Flushing
- Diarrhoea
- Bronchoconstriction / tachycardia
Which test is used to diagnose carcinoid syndrome ?
- 24 hour urine 5-HIAA
Which paediatric disease presents with up to 100 hamartomatous polyps in children <5 years old ?
Juvenile polyposis
List 3 features of peutz-jeghers syndrome ?
- multiple hamartomatous polyps
- freckles around mouth
- mucocutaenous hyperpigmentation
Which staging system is used to stage colorectal adenocarcinoma?
Duke’s staging
- A= confined to bowel wall
- B= through wall of bowel
- C= lymph node metastases
- D= distant metastases
Which tumour marker identifies colorectal cancer ?
CEA
where do 90% of diverticuli occur
left colon
therapy for pseudomembranous colitis
metronidazole or vancomycin
at what sites do ischaemic colitis/ infarction occur
- segments in ‘watershed’ zones
- such as splenic flexure (SMA and IMA), rectosigmoid (IMA and IIA)
list causes of ischaemic colitis
- arterial occlusion
- venous occlusion
- small vessel disease - DM, cholesterol, emboli, vasculitis
- low flow states - shock, haemorrhage
- obstruction - hernia, intussusception, adhesions
list 3 complications of UC
- severe haemorrhage
- toxic megacolon
- adenocarcinoma
list some extra-intestinal features of UC (5)
arthritis
myositis
uveitis/iritis
Erythema Nodosum, PG
PSC
list 3 non neoplastic polyps of the colon and rectum
hyperplastic
inflammatory (pseudo-polyps)
hamartomatous (juvenile, peutz jeghers)
list 3 neoplastic polyps (increase R of cancer) of the colon and rectum
tubular adenoma
tubulovillous adenoma
villous adenoma
list risk factors for the development of cancer from a polyp
size of polyp (>4cm - 455 have invasive malignancy)
proportion of villous component (more villousy = more R)
degree of dysplastic change within the polyp
