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