Vasoinhibitory polypeptide tumor

　　Islet cell hyperplasia is one of the causes of VIPoma syndrome, and this disease has a genetic tendency.

　　Islet cell hyperplasia (45%):
　　Islet cells are divided into the following types according to their secretion of hormones:
　　First, B cells (beta cells), accounting for 60% to 80% of islet cells, secrete insulin, which can lower blood sugar levels. The lack of islet B cells will lead to the occurrence of diabetes.
　　Second, A cells (alpha cells), accounting for 24% to 40% of islet cells, secrete glucagon, the effect of glucagon is opposite to that of insulin, which can increase blood sugar levels.
　　Third, D cells, accounting for 6% to 15% of the total number of islet cells, secrete somatostatin inhibitory hormone.
　　Heredity (30%):
　　The occurrence of this disease is related to heredity. If either parent or other relatives have the disease, the offspring may also develop the disease. Therefore, the occurrence of vasoinhibitory polypeptide tumor is closely related to heredity.

　　Vasoinhibitory polypeptide tumor may be complicated with hypophosphatemia, hypercalcemia, hyperglycemia, kidney stones, and other symptoms, which seriously affect the physical health of patients and threaten their lives, so timely treatment is essential.

　　1. Diarrhea

　　The most prominent symptom of this disease is massive secretory diarrhea, with 70% of patients having more than 3L of diarrhea per day, with stools thin as water, appearing like tea color. Diarrhea often occurs suddenly and explosively, but in severe cases, it may be persistent. VIPoma patients may still experience persistent diarrhea after fasting for 48 to 72 hours, so fasting for 72 hours can be used to differentiate from diarrhea caused by other reasons.

　　2. Disturbance of water, electrolyte, and acid-base balance

　　Due to persistent and severe diarrhea, there may be significant loss of electrolytes, leading to varying degrees of dehydration, decreased circulatory blood volume, hyponatremia, hypochloremia, metabolic acidosis, and disturbances in water, electrolyte, and acid-base balance. Severe cases may further lead to arrhythmias, hypokalemic nephropathy, or renal failure, and even death.

　　3. Low gastric acid or no gastric acid

　　About 3/4 of patients have reduced gastric acid secretion, even without gastric acid, and the mechanism is that vasoactive intestinal peptide can inhibit the secretion of gastric acid stimulated by pentagastrin, resulting in reduced gastric acid levels. Some patients may develop agastric acid, and biopsies of the gastric mucosa show normal numbers of parietal cells, further indicating that the reduction in gastric acid is not related to changes in the parietal cells themselves.

　　4. Hypophosphatemia and hypercalcemia

　　About 60% of patients may have hypophosphatemia, 50% of patients have hypercalcemia, and the mechanism of calcium and phosphorus metabolism disorders has not been fully elucidated. Since hypercalcemia and hypophosphatemia can return to normal after tumor resection, it is speculated that this may be related to the increased secretion of parathyroid-like hormone by the islet tumor itself.

　　5. Reduced glucose tolerance and hyperglycemia

　　About 50% of patients have reduced glucose tolerance, while those with increased blood sugar levels are slightly fewer, about 18%, due to the molecular structure of vasoactive intestinal peptide being very similar to that of glucagon, which may lead to a glucagon-like effect; it may also be a result of the impact of hypokalemia on islet function, as glucose tolerance can also return to normal after tumor resection.

　　6. Others

　　About 62% of VIPome patients may have abdominal cramps; 20% of patients may experience paroxysmal flushing of the skin, often occurring on the face or chest; Bloom reported that 4% of patients develop kidney stones, the mechanism of which is still unclear.

　　Vasoactive intestinal peptideoma has a certain genetic predisposition. It is important to conduct pre-pregnancy examinations to prevent the birth of affected children. Regular screening of high-risk populations is crucial for early diagnosis and treatment, which is the key to the prevention and treatment of this disease.

　　1. Laboratory examination

　　Dehydration, hypokalemia, hypochloremia, metabolic acidosis, low gastric acid, hypercalcemia, hypomagnesia, and reduced glucose tolerance.

　　Serum vasoactive intestinal peptide (VIP) determination

　　Normal fasting serum VIP levels in healthy individuals range from 0 to 170 pg/ml, with an average of 62±22 pg/ml; VIPoma patients have significantly elevated serum VIP levels, averaging 956±285 pg/ml, with some reaching as high as 2400 pg/ml.

　　Third, localization diagnosis

　　Since VIPoma itself is a rare disease, there is a lack of systematic research on the localization diagnostic methods of this disease.

　　1. Ultrasound and CT:It can show the location, size, and number of the tumor, and understand whether there is liver or surrounding lymph node metastasis, so it is often used as the preferred localization examination surgery.

　　2. Selective pancreatic arteriography:It can increase the accuracy and diagnostic rate of localization examination, but it can also have false-negative or false-positive results, and it is also difficult to distinguish the specific type of islet tumor.

　　3. Percutaneous liver puncture portal vein system catheterization blood collection method (PT-PC):By measuring the concentration of vasoactive intestinal peptide in the portal vein blood from different parts, it is helpful to determine the location of the tumor.

　　4. Intraoperative ultrasound:It is helpful to discover small tumors located within the pancreas.

　　What foods should be eaten for the tumor:

　　1. Fresh, easily digestible foods rich in high-quality protein, vitamins, and minerals should be the main choice, with fresh vegetables and fruits being essential at each meal.

　　2. Eat more foods that have certain anticancer effects, such as cauliflower, cabbage, broccoli, asparagus, legumes, mushroom, sea cucumber, and flatfish, etc.

　　3. Foods with the function of softening hard lumps and dispersing nodules should be chosen: such as kelp, seaweed, wakame, sea cucumber, abalone, cuttlefish, kelp, turtle, red beans, radish, rapeseed, grass, mushrooms, etc.

　　4. Different foods should be chosen according to different constitutions. People with weak spleen and stomach, and insufficient middle qi, can eat squab, magpie, eggs, jujube, red dates, ginger, garlic, fresh mushrooms, etc.; those with Yin deficiency of liver and kidney can use black chicken meat, pork kidney, black beans, black sesame seeds, walnuts, abalone meat, etc.; those with blood deficiency can eat pork liver, pork bones, goose blood, spinach, soy products, etc.

　　First, surgical treatment

　　Surgical resection of the tumor is the preferred method of treatment for this disease, and the specific surgical method selection follows the following principles:

　　1. For small, solitary tumors, tumor excision or partial pancreatectomy can be adopted.

　　2. If the tumor is located at the tail of the pancreas, the tail of the pancreas can be resected, or a body-tail resection can be performed, which can usually be cured.

　　3. If the tumor focus is not found during preoperative and intraoperative examinations, a blind subtotal pancreatectomy can be performed because 75% of the tumors in this disease are located in the body and tail of the pancreas.

　　4. During surgery, the sympathetic nerve distribution area from the adrenal glands to the bladder should be carefully explored to determine the presence of ganglioneuroma. The surgical outcome of ganglioneuroma is generally good.

　　5. Radical resection should also be sought for metastatic tumors. Even if tumor debulking surgery is performed, it can alleviate the clinical symptoms of the disease. Nagorney reported that reoperation for the resection of recurrent VIPoma resulted in sustained remission of the condition.

　　6. In cases of widespread non-B cell hyperplasia of the pancreas, partial resection of the tail of the pancreas can be performed first. If the symptoms improve after surgery, a second operation for total pancreatectomy can be performed, with 80% of patients being cured.

　　1. Drug treatment is very important for stabilizing the condition before surgery, correcting metabolic disorders, and for advanced patients who do not have surgical indications. First, a large amount of fluid should be administered to correct dehydration, electrolyte imbalance, and acid-base imbalance. Oral glucose and electrolyte solutions are better than intravenous infusion because the former can promote the absorption of water and electrolytes in the jejunum and reduce the loss of body fluids in the feces.

　　2. To control diarrhea, prednisone tablets can be used at a dose of 60-80mg per day; Indomethacin, as a prostaglandin inhibitor, can reduce the amount of diarrhea, at a dose of 25mg orally every 8 hours; Lithium carbonate 300mg, twice a day, can also reduce the amount of diarrhea but does not reduce the VIP level, its mechanism is to inhibit cyclic adenosine monophosphate (cAMP).

　　1. Drug treatment is very important for stabilizing the condition before surgery, correcting metabolic disorders, and for advanced patients who do not have surgical indications. First, a large amount of fluid should be administered to correct dehydration, electrolyte imbalance, and acid-base imbalance. Oral glucose and electrolyte solutions are better than intravenous infusion because the former can promote the absorption of water and electrolytes in the jejunum and reduce the loss of body fluids in the feces.

　　2. The most effective drug for the treatment of this disease is octreotide acetate (Octreotide acetate), which can reduce the level of VIP in the circulating blood, reduce the amount of diarrhea, correct electrolyte and acid-base imbalance, and hypercalcemia caused by VIP. It is reported that the effective rate is 70%; it can also inhibit the secretion of other polypeptide substances by the tumor, which can cause some clinical symptoms. Octreotide acetate is also the first-line drug for patients with advanced VIPoma. However, some patients may not respond to drug treatment.

　　3. Chemotherapy

　　1. Chemotherapy is effective for the treatment of metastatic tumors and may also control the symptoms of patients for whom drug treatment has not been effective. Streptozotocin (Streptozotocin) is used at a dose of 20-30mg/kg of body weight, administered intravenously once a week, and can be used for 8-10 times in a row; it can also be directly injected into the celiac artery at a dose of 5-10mg/kg of body weight. It is reported that the effective rate is 50%, and it can also cause the tumor to shrink. If 5-Fu is added, it can enhance the efficacy of Streptozotocin. The method of injecting medication into the celiac artery has multiple effects, such as reducing the dose, enhancing the efficacy, and reducing nephrotoxic reactions.

　　2. Interferon therapy can reduce the amount of diarrhea, lower the level of plasma VIP, and even cause the tumor to shrink to some extent; but the effects reported by different parties are not consistent.