Colonic Pathology - Crohn's and UC

Question 1

Crohn’s Disease - Epidemiology

Answer 1

• Common in North America and Northern Europe
• Prevalence from 30 to 100 per 100000
• Family history common
  
  • Relative risk for a sibling is 13-36
• Maximal incidence in young adults 15-30 yrs

Question 2

Crohn’s Diease - GI Distribution

Answer 2

• Any portion of the GI tract can be affected but pattern of anatomical involvement is important
• Involvement of both terminal ileum and caecum in 40-50%
• In 20% of patients disease confined to the colon
• Discontinuous or “skip” lesions on colonoscopy or barium studies are characteristic

Question 3

Crohn’s Disease - Macroscopic Histopathology

Answer 3

• Transmural inflammation
• Non-necrotising granulomas (40-60%)
• Crypt abscesses
• Ulcers may penetrate deeply forming fissures in the muscularis propria leading to abscess and fistula formation
• Healing of these penetrating lesions is responsible for fibrosis and stricture formations

Question 4

Crohn’s Disease - Histopathology

Answer 4

• Transmural inflammation
• Non-necrotising granulomas (40-60%)
• Crypt abscesses
• Ulcers may penetrate deeply forming fissures in the muscularis propria leading to abscess and fistula formation
  
  • Healing of these penetrating lesions is responsible for fibrosis and stricture formations

Question 5

Crohn’s Disease - Complications

Answer 5

• Inflammatory adhesions
• Perforation
• Perirectal disease (perianal fistulas and abscesses)
• Malabsorption
• Small bowel adenocarcinoma

Question 6

Crohn’s Disease - Treatment

Answer 6

• 5-Aminosalycilic acid
• Steroids
• Immunosuppressive drugs
• Monoclonal antibodies against TNF-α (Infliximab)
• Surgery

Question 7

Ulcerative Colitis - Epidemiology

Answer 7

• Common in North America and Northern Europe
• Prevalence from 35 to 50 per 100000
• Family history common, relative risk for a sibling is 7-17
• Maximal incidence in young adults 20-50 yrs
  
  • Second peak 60-70 yrs

Question 8

Ulcerative Colitis - Histolopathology

Answer 8

• Crypt abscesses with neutrophils within the crypt, in the crypt wall and in the lamina propria
• Crypt architectural distortion, with gland branching, shortening and loss of the normal parallel arrangement of glands

Question 9

Ulcerative Colitis - Complications

Answer 9

• Toxic Megacolon - due to paralysis of motor function of transverse colon - 30% mortality
  
  • High fever
  • Tachycardia
  • Diarrhoea
• Perforation
• Massive haemmorhage
• Colon cancer - corellation to extent and duration of disease

Question 10

Ulcerative Colitis - Treatment

Answer 10

• 5-ASA
• Steroids
• Immunosuppressive drugs
• Surgery