+ 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


+ Radiographs

  • 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

+ Ultrasonography

  • 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

+ Endoscopy

  • 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

  • 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

+ Chemotherapy

No known effective chemotherapy agents for gastric carcinoids, consider somatostatin analogues

+ Prognosis

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