My cat had a tumor removed from his pancreas yesterday. The veterinarian said it was probably a gastrinoma; the pathology report is not back yet. The doctor also removed part of the cat's stomach because it had a big ulcer. What is a gastrinoma and what is the prognosis? The veterinarian said there were no gross signs of tumor spread to the liver or lymph nodes.
A gastrinoma is a rare, malignant tumor of the pancreas of dogs and cats. Gastrinomas arise from pancreatic islet cells (but not the insulin-producing beta cells) and secrete excessive amounts of gastrin, which stimulates the stomach to release excessive amounts of digestive hydrochloric acid. The excess stomach acid causes inflammation, erosion and ulceration in the stomach, duodenum (first part of the small intestine) and lower esophagus. The excess gastrin also stimulates the thickening of the stomach's lining. It causes the formation and release of other digestive substances as well.
Gastrinoma is more likely to occur in older dogs and cats. It is more prevalent in females than in males.
Gastrinoma and its influence on stomach acid and other digestive substances cause numerous nonspecific signs of disease. Affected dogs and cats may vomit, have diarrhea, experience weight loss and loss of appetite. They may show signs of depression and have abdominal pain. Blood may appear in the stool or vomitus. Affected animals may drink excessively. Blood tests will likely demonstrate anemia, elevation of gastrin concentration and blood sugar, and abnormally low albumin, calcium, potassium and chloride levels.
Although contrast x-rays and endoscopic study will reveal the presence of ulcers and other structural changes of the gastrointestinal tract, the only diagnostically definitive way of proving a gastrinoma is present is by open surgical biopsy. If a tumor is present and is removable, the entire mass will be excised, along with metastatic (spread) tumors to the liver and other tissues. Biopsy samples of the liver and nearby lymph nodes are typically taken as well. The resected tissues are sent to a pathologist for a definitive cellular diagnosis. Surgical treatment of severe gastrointestinal ulceration will usually be given at the same surgical setting.
Prognosis is poor, primarily because of the tendency of these tumors to spread early. Life expectancy after surgery averages less than six months, although some patients have lived as long as one and a half years. However, your cat may experience a more favorable outcome since your veterinary surgeon did not find any gross signs of tumor spread. With complete excision of the tumor and if the liver and lymph node biopsies are cancer free, a better prognosis might be anticipated. You may wish to consult with a veterinary oncologist about diagnostic and treatment options once the pathology results are made available.
04/25/01
