13.01.17 Pathology teaching

Granuloma

• • Aggregate of ACTIVATED (epithelioid) macrophages

  • Causes:

    • TB

    • Sarcoid

    • Crohn's

Crohn's

• • Ileocecal area

  • Rectal sparing

  • Patchy distribution

  • Aphthous ulcers

  • Transmural inflammation

    • Adhesions

    • Fistulas

    • Strictures

  • GRANULOMAS

  • Fissuring ulcers

    • => Cobblestoning (areas of surviving mucosa between fissures)

  • Dysplasia is less common

UC

• • Affects mucosa only

  • Crypt abscesses

    • In mucosa

    • Full of neutrophils

  • Extensive, diffuse inflammation

  • Dysplasia is common

    • Because it affects the mucosa

Bowel obstruction

• • Features

    • Absolute constipation

      • Faeces

      • Flatus

    • Colicky pain

    • Vomiting

    • Abdominal distension

  • Small bowel

    • Adhesions (=> kinking)

    • Crohn's

    • Volvulus

    • Hernia

    • Intususception

  • Large bowel

    • CRC

      • 25% present with obstruction

    • Diverticular strictures

    • Sigmoid volvulus

Ileus

• • Clinical features

    • Mimics obstruction

      • Distension

      • Vomiting

    • BUT pain is from the underlying disorder, not from the bowel

      • Bowel is paralysed => No colicky pain

  • Causes

    • Post-op

    • Any cause of peritonitis

    • Opioids

    • Electrolyte imbalance

Notes

• • 4 signs of acute inflammation, plus LOF

  • Neutrophils climb along fibrin scaffold

  • IL-6 stimulated mediators

    • CRP

      • Opsonin

      • Complement activation

    • Fibrinogen

    • Mannose binding lectin

  • Granulation tissue is PINK

    • Huge proliferation of capillaries

  • Pseudomonas => Green tinge

  • Old patient with rectal bleeding

    • Angiodysplasia

    • Ischaemic bowel disease

    • Ca

  • Anterior resection = Removal of all or part of the rectum, with primary anastamosis

    • cf APR

  • Obstruction: Pain progresses from colicky to peritonitic as bowel is paralysed and dies