Neoplasia, Intestinal

• Neoplasia in structures adjacent to the intestines can spread and cause external compression.
• Pancreatic tumours in particular can extend and impinge on the duodenum.
• Pedicles of tumours such as lipomas in horses can become wound in loops of intestine leading to obstruction and possible strangulation.

Closeup of a pedunculated lipoma (Courtesy of Elspeth Milne)

• Clinical
  • Occasional vomiting and ntermittent diarrhoea over several weeks.
• Pathogenesis
  • Seen occasionally in cat (rarer in dog)
  • Usually towards end of intestines
    • E.g. at the ileocaecocolic valve.
  • Gut proximal to tumour becomes thickened due to hypertrophy of smooth muscle as a result of trying to force ingesta past progessively narrowing lumen.
  • Produces "hose pipe intestine".
  • Seen with carcinoma, lymphoma, leiomyoma and other tumours.