Diverticula, IBD, Colorectal cancer Flashcards
Which diverticula are acquired or congenital?
- Sigmoid diverticulosis (a)
- Diverticulosis of R colon (a&c)
- Giant diverticulum
What is diverticulosis of the colon?
- Protrusion of mucosa & submucosa through bowel wall
- Commonly sigmoid
- Located b/ween mesenteric & anti-mesenteric taenia coli
What is the pathology of diverticulosis?
-Inc intra-luminal pressure: irregular/uncoordinated peristalsis, overlapping semicircular arcs of bowel wall
-Points of weakness in bowel wall
age related changes in connective tissue, penetration by nutrient arteries
-Elastosis of taeniae coli leading to shortening of colon
-Sacculation
-Redundant mucosal folds & ridges
-Thickening of muscular propria
What are clinical features of diverticular disease?
- Asymptomatic= 99%
- Cramping abdo pain
- Alternating constipation/ diarrhoea
- Acute & chronic complications
What are acute complications of diverticulosis?
- Diverticulitis/ peridiverticular abscess
- Perforation
- Haemorrhage
What are chronic complications of diverticulosis?
- Fistula
- Intestinal obstruction
- Diverticular colitis (segmental & granulomatous)
- Polypoid prolapsing mucosal folds
What are the different types of acute colitis?
- Acute infective colitis ( campylobacter, salmonella, CMV)
- Antibiotic associated colitis (PMC)
- Drug induced colitis
- Acute ischaemic colitis (transient or gangrenous)
- Acute radiation colitis
- Neutropenic colitis
- Phlegmonous colitis
What are the different types of chronic colitis>
- Chronic idiopathic IBD (UC, Crohn’s, indeterminate colitis)
- Microscopic colitis (collagenous & lymphocytic)
- Ischaemic colitis
- Diverticular colitis
- Chronic infective colitis (amoebic colitis & TB)
- Diversion colitis
- Eosinophilic colitis
- Chronic radiation colitis
What is the clinical presentation of ulcerative colitis? And complications
-Diarrhoea w/ urgency/tenesmus
-Constipation
-Rectal bleeding
-Abdominal pain
-Anorexia
-Weight loss
-Anaemia
Complications: stricture (rare), carcinoma, haemorrhage, toxic megacolon & perforation
What are the clinical features of Crohn’s disease?
- Chronic relapsing disease
- From mouth to anus
- (bloody) diarrhoea
- Colicky ado pain
- Palpable abdo mass
- Weight loss/ failure to thrive/anorexia
- Anaemia
- Peri-anal disease
- Fever
- Oral ulcers
What are complications of Crohn’s disease?
- Toxic megacolon
- Perforation
- Fistula
- Stricture (common)
- Haemorrhage
- Carcinoma
- Short bowel syndrome
What are the differences between UC & CD?
UC: affects colon, appendix, terminal ileum, continuous disease, rectum always involved, normal series, granular red mucosa w/flat undermining ulcers, anal lesions=25%, mucosal inflammation, crypt abscesses common, inflammatory polyps, crypt distortion severe
CD: mouth to anus, skip lesions, rectum involved=50%, strictures common, fistulae, anal lesion=75%, cobblestone appearance w/apthoid & fissuring ulcers, serositis, transmural inflammation, sarcoid like granulomas present
What are extra-intestinal manifestations of IBD?
- Hepatic: fatty change, bile duct carcinoma, granulomas
- Skeletal: polyarthritis,ankylosing spondylitis
- Ocular: Retinitis, iritis/uveitis
- Renal: Kidney stones
- Systemic: vasculitis, amyloid
- Haem: anaemia, thrombocytosis, leucocytosis
What are the types of colorectal polyps?
- Neoplastic, hamartomatous, inflammatory, reactive
- Benign or malignant
- Epithelial or mesenchymal
Name some non-neoplastic polyps in the colo-rectum. Describe some of them
- Hyperplastic polyp= common in rectum & sigmoid colon, small,distal = no malignant potential
- Hamartomatous polyp (juvenile= spherical & pedunculated, usually rectum & distal colon, sporadic so not malignant or Peutz-jeghers=aDominant, multiple polyps in gastro-intestinal tract, muco-cutaneous pigmentation)
- Polyps related to mucosal prolapse
- Post-inflammatory polyp
- Inflammatory fibroid polyp
- Benign lymphoid polyp
Name some benign and malignant neoplastic polyps
- B: adenoma, lipoma, leiomyoma, haemangioma, neurofibroma
- M: carcinoma, carcinoid, GIST, leiomyosarcoma, lymphoma, metastatic tumour
Describe adenomas
- Benign epithelial tumours
- Precursor of colorectal cancer
- Evenly distributed around colon but larger in recto-sigmoid & caecum
- Pedunculated, sessile or flat
- Villous, tubilo-villous or tubular
- High to v. low grade dysplasia
What characteristics of an adenomas show a risk of malignant change?
- Flat adenomas
- Size> 10mm
- Villous & tubulo-villous
- Severe/high grade dysplasia
- HNPCC associated
What are risk factors for colorectal cancer
- Diet (fat, red meat, folate, Ca, dietary fibre)
- Obesity/ physical activity
- Alcohol
- NSAIDs
- HRT/oral contraceptives
- Schistosomiasis
- Pelvic radiation
- UC & Crohn’s
What are the forms of colorectal cancer?
- Adenocarcinoma (95%)
- Adenosquamous carcinoma
- Squamous cell carcinoma
- Neuroendocrine carcinoma
- Undifferentiated (large cell) carcinoma
- Medullary carcinoma
How does colorectal cancer spread?
- Direct invasion of adjacent tissue
- Lymphatic metastasis
- Haematogenous metastasis (liver & lung)
- Transcoelomic (peritoneal) metastasis
- Iatrogenic spread (needle track, port site recurrence)
What are the stages in Dukes staging?
A: Adenocarcinoma confined to bowel wall
B: Invading through bowel wall
C: With regional lymph node mets regardless of depth of invasion
D: Distant mets present
