Veterinary Society of
Surgical Oncology

GENERAL CONSIDERATIONS

General Considerations

  • LSA is the most common gastric tumor in cats (solitary or multicentric) and most are FeLV negative
  • sex predisposition: males
  • gross appearance: discrete mass or diffuse gastric wall diffusion

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

Imaging

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

TREATMENT

Surgery

  • surgery is possibly solitary feline gastric LSA 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

  • gastric LSA does not respond well to conventional chemotherapy protocols and chemotherapy may not be required following surgical resection of solitary gastric LSA in cats

Prognosis

  • prognosis depends on surgical excision, tumor type and grade, and presence of metastatic lesions
  • gastric LSA: MST 40 weeks with Madison-Wisconsin protocol and 15.5 months with prednisolone-chlorambucil

GASTRIC LYMPHOSARCOMA

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