Vipoma is a tumor originating from the islet cells of the pancreas. It is usually localized in the tail or in the body of the pancreas, less often located in the area of the sympathetic trunk. More than half of the cases are malignant. It is manifested by massive diarrhea, diffuse abdominal pain, severe disorders of water-salt metabolism, hypotension, convulsions and renal insufficiency due to loss of salts and fluid. The diagnosis of vipoma is established on the basis of symptoms, test results, ultrasound, CT, MRI and other studies. Treatment – drug therapy, surgical intervention.
Vipoma (Werner-Morrison syndrome or pancreatic cholera) is a neoplasm that produces a large amount of vasoactive interstitial peptide (VIP). It is included in the group of tumor diseases of the APUD system – neuroendocrine cells located in various organs and united by certain common properties. 50-75% of vipomas at the time of detection have signs of malignant neoplasm, in many cases metastases to other organs (usually to the liver) are detected during the diagnosis process. Vipoma is a very rare disease. The prognosis is unfavorable in most cases. The treatment is carried out by specialists in the field of oncology and gastroenterology.
Symptoms of vipoma
The main clinical manifestation of vipoma is massive prolonged diarrhea. The daily volume of the stool against the background of fasting is about 1 liter, against the background of eating, it can increase to 3-4 liters or more. 50% of patients with vipoma suffer from diarrhea constantly, the rest have a wave-like course. Due to significant losses of fluid and trace elements, dehydration, acidosis, hypokalemia and severe weakness occur. Seizures due to magnesium losses are possible.
Patients with vipoma lose weight. There is a tendency to lower blood pressure. Kidney failure develops. Mental disorders appear. Patients with vipoma may complain of abdominal pain of indeterminate localization. The gallbladder may increase, the probability of gallbladder stones formation increases. The level of gastric juice secretion decreases. In 20-30% of cases, hot flashes occur. Every third patient with vipoma has hyperglycemia due to increased production of glucagon and intensive destruction of glycogen. When conducting additional studies, a tumor-like formation is detected in the area of the pancreas or sympathetic trunk. The diameter of the vipoma can reach 7 centimeters or more.
The diagnosis is established on the basis of clinical manifestations, test results and additional research data. During the diagnosis, other possible causes of prolonged diarrhea are excluded (infectious diseases, mastocytosis, villous adenoma, taking laxatives, etc.). Patients with suspected vipoma are prescribed general blood and urine tests, a blood test to determine the level of VIP, a coprocytogram and a biochemical blood test to determine the level of salts, protein and aminotransferases. The daily volume of stool is measured during meals and after three days of fasting.
The plan of instrumental examination for vipoma includes EGD, ultrasound of the pancreas, CT or MRI of the pancreas. Diagnostic criteria for vipoma are diarrhea lasting more than 3 weeks with a daily stool volume of more than 700 ml; daily stool volume of more than 500 ml against a background of three-day fasting; high levels of VIP in the blood; the presence of tumor-like formation in the pancreas (in 90% of cases) or in the sympathetic trunk (in 10% of cases) according to ultrasound, CT or MRI results.
Differential diagnosis of vipoma is carried out with Zollinger-Ellison syndrome (gastrinoma). Unlike this syndrome, recurrent ulcers of the stomach and duodenum do not occur with vipoma, more pronounced watery diarrhea is observed, there is no steatorrhea. According to laboratory studies, hypo- or achlorhydria of gastric juice, a sharp increase in the level of VIP, a decrease in the level of sodium and potassium in the blood are detected during vipoma. Gastrinoma reveals hyperchlorhydria of gastric juice and a normal level of VIP. Sodium and potassium levels are usually normal, but may decrease with copious vomiting.
Treatment of vipoma
The primary task in the treatment of vipoma is the correction of gross violations of water-salt metabolism. Intravenous bicarbonate infusions are carried out. As rehydration increases, the volume of the stool increases, so constant adequate replenishment of lost fluid can present certain difficulties. To reduce the daily volume of stool, prednisone or streptozocin is administered in combination with 5-fluorouracil. To suppress the secretion of VIP, octreotide is prescribed. The drug also helps to reduce diarrhea and sometimes reduces the size of the vipoma. Octreotide also suppresses pancreatic secretion, so pancreatin is used if necessary.
The most effective method of treating vipoma is radical surgical intervention. After removal of the tumor, complete recovery is observed in 50% of patients. In the presence of metastases, palliative operations are performed to remove the identified foci to reduce the severity of symptoms and alleviate the condition of the patient suffering from vipoma. At the same time, streptozocin is prescribed in combination with fluorouracil or doxorubicin. Palliative surgical interventions in combination with chemotherapy do not allow for full recovery, but provide partial remission and improve the quality of life of patients.
- Perioperative Management and Anaesthetic Considerations for Pancreatic Resection Surgery / Seema Pai, Tim Hughes // General Anaesthesia. — 2018
- Goral V. Pancreatic Cancer: Pathogenesis and Diagnosis // Asian Pac J Cancer Prev. — 2015; 16 (14), 5619-5624.link
- Wolpin B.M., Ng K., Bao Y., Kraft P., Stampfer M.J. et al. Plasma 25-hydroxyvitamin D and risk of pancreatic cancer // Cancer Epidemiol Biomarkers Prev. — 2012. — V. 21, N 1. — P. 82-91.link
- Duell E.J., Lucenteforte E., Olson S.H. et al. Pancreatitis and pancreatic cancer risk: a pooled analysis in the International Pancreatic Cancer Case-Control Consortium (PanC4) // Ann Oncol. — 2012. — V. 23, N 11. — P. 2964-70.
- Huang Y., Cai X., Qiu M. et al. Prediabetes and the risk of cancer: a meta-analysis // Diabetologia. — 2014. — V. 57, N 11. — P. 2261-9.link