Colonic Polyps

Introduction

  • There are 3 types of benign polyps (hamartomas)
    • hyperplastic polyp
      • most common type in adults
      • often rectosigmoid
      • sawtoothed appearance
      • does NOT predispose to malignancy
    • juvenile polyps
      • most common type in children
      • often rectosigmoid
    • Peutz-Jeghers polyposis 
  • There are 3 types of neoplastic polyps (adenomas)
    • tubular adenoma
      • most common polyp
      • usually pedunculated (stalked)
    • tubulovillous adenoma
      • usually pedunculated (stalked)
    • villous adenoma
      • greatest malignant potential 
      • usually sessile
      • may secrete protein and K+-rich mucus
  • may involve Familial Adenomatous Polyposis 

Presentation

  • Sympoms
    • rectal bleeding
  • polyp prolapse from rectum

Evaluation

  • Sigmoidoscopy / colonoscopy
  • Labs
  • villous adenoma may show hypokalemia and hypoalbuminemia

Differential

  • Polyposis syndromes
    • Juvenile polyposis
      • AD inheritance
      • multiple juvenile polyps in GI tract
      • ↑ risk of adenocarcinoma
    • Cronkhite-Canada syndrome 
  • consists of juvenile polyposis with fingernail dystrophy

Prognosis, Prevention, and Complications

  •  Malignancy risk ↑ by
    • ↑ size
    • ↑ villous histology
      • villous = villainous
    • ↑ epithelial dysplasia