Veterinary Society of
Surgical Oncology


General Considerations

  • gastric carcinoids are tumors of the enterochromaffin system and are referred to as amine precursor uptake and decarboxylation tumors or APUDomas
  • gastric carcinoids are functional and, in humans, are diagnosed by clinical presentation, measurement of urinary serotonin metabolites, provocative pentagastric testing, radionucleide scans, and CT
  • carcinoids are locally invasive, and metastasize to regional lymph nodes, lungs, pleura, and peritoneum
  • carcinoids usually occur in geriatric animals and gastric carcinoid has been reported in a 15-year-old cat

Clinical Signs

  • clinical signs are caused by gastric outflow obstruction, altered motility, or chronic blood loss secondary to tumor necrosis and ulceration
  • progressive vomiting is common and may contain fresh or digested blood
  • weight loss may be caused by poor digestion, protein malnutrition, or cancer cachexia

Laboratory Tests

  • laboratory tests and survey radiographs are usually unrewarding
  • microcytic hypochromic anemia is common with chronic blood loss and occult blood may be detected in feces
  • increased liver enzymes may be seen with hepatic metastasis or obstruction of the common bile duct



  • positive- or double-contrast radiographs: gastric tumors can appear as a mass effect, ulcer crater, delayed gastric emptying with poor motility, and delayed adherence of contrast material to an ulcerated tumor


  • ultrasonographic findings include transmural thickening of the gastric wall with loss or altered layering (poor echogenic outer and inner lining with hyperechoic central zone)
  • other findings include tumor location, ulceration, extension through gastric wall, and lymphadenopathy


  • gastroscopy allows direct visualization and guided biopsy
  • several biopsies should be performed as superficial ulceration, necrosis, and inflammation is common
  • submucosal masses are difficult to biopsy and false-negative results are common

Other Imaging Techniques

  • CT and MRI



  • surgery is recommended for gastric carcinoids, but complicated by advanced stage at presentation, frequent metastasis, difficult access, and debilitated animal
  • lymph node metastasis is variable and all abdominal lymph node should be evaluated for staging purposes
  • curative resection should be attempted if disease is localized to the stomach
  • surgical techniques: Billroth I or II or palliative bypass procedures
  • Billroth I or II provides immediate relief of gastric outflow obstruction and clinical improvement in early postoperative period
  • Billroth II (partial gastrectomy and gastrojejunostomy) or complete gastrectomy (with biliary by-pass) are very extensive surgeries with high morbidity and minimal survival advantage
  • partial gastrectomy preferred in humans due to better nutritional status and quality of life and radical gastrectomy does not improve survival time
  • palliative gastrojejunostomy for inoperable or metastatic lesions but associated with significant morbidity including anastomotic ulcers


  • no known effective chemotherapy agents for gastric carcinoids, consider somatostatin analogues


  • prognosis depends on surgical excision, tumor type and grade, and presence of metastatic lesions
  • prognosis is unknown for gastric carcinoids


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