Villus atrophy with damage to crypts

• The primary insult is to crypt cells.
  • Crypt cell death leads to dilated gland lumens (cysts).
  • Production is impaired, eventually leading to insufficient cells for villi.
• Enterocytes lost to lumen are replaced by increasingly immature cells.
  • Gives rise to severe malabsorption.
• If damage is severe, erosions/ulcers may form which may eventually heal.
  • Even if there are no ulcers, damage can be long-term
    • Causes long-term malabsorption.
• Examples include:
  • Parvovirus
    • Target crypt cells.
  • Lymphoma
    • Numerous neoplastic lymphocytes compress crypts.
  • Cytotoxic chemicals
    • Dividing crypt cells are susceptible.