pancreatic polypeptide tumor
Introduction
Introduction to pancreatic polypeptide Pancreatic polypeptide (PP) is secreted by pancreatic PP cells (or F cells). PP cells are distributed in islet tissue or scattered in the pancreatic exocrine glands. Pancreatic polypeptidoma (PPoma) is a pancreatic secretory PP. Endocrine tumors with increased cells. basic knowledge The proportion of illness: the incidence rate is about 0.0001%-0.0003% Susceptible people: no special people Mode of infection: non-infectious Complications: abdominal pain
Cause
Pancreatic polypeptide tumor etiology
Causes:
Because the pancreatic PP cells secrete a large amount of pancreatic polypeptide, the pathological manifestation caused by the pancreatic polypeptide is produced.
Pathogenesis:
After the separation of PP by Chance, Kimmel and Pollack in 1972, there have been some reports on its physiological effects. PP increased significantly after eating, lasting for 6-8 hours. The physiological significance of biological function and post-meal increase is not clear. It may be to regulate the enzyme after meal, the secretion of digestive juice is not excessive or the secretion time is too long, and it plays a certain degree of "brake" effect. However, the physiological effects of PP are not known at present. Greenberg et al believe that the physiological role of PP in humans is Inhibition of gallbladder contraction and promotion of pancreatic juice secretion.
PPoma is located in the head of the pancreas. It is located in the tail of the body. A small number of patients have tumors distributed in the external organs of the pancreas. The tumors have a complete capsule. The lesions may see hemorrhagic necrosis and cystic changes. The tumors are often larger and larger in diameter. More than 5cm; tumors are often single, most of the disease is malignant, a small part of benign tumors or only PP cell proliferation, malignant PPoma common metastatic site is the liver, but can also be transferred to the lungs, brain and bones, through immune tissue Chemical method, using a variety of gastrointestinal hormone antiserum for examination, the highest content of PP, other gastrointestinal hormones are negative or weak positive, determination of PP in tumor tissue, its content is extremely high, up to 196.5g / g wet tissue However, other gastrointestinal hormones were very small or negative. Using electron microscopy, the particle morphology in the tumor cells was consistent with that of the PP particles.
Prevention
Pancreatic polypeptide tumor prevention
There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease. Eat less greasy foods; eat less warm food such as dog meat and lamb; eat less shellfish, bamboo shoots, clams and other allergic "hair products"; eat less beverages containing chemicals, preservatives, additives and Snacks. Do not eat too acidic, too spicy, too salty, alcohol and other irritants.
Complication
Pancreatic polypeptide tumor complications Complications, abdominal pain
Pancreatic polypeptide tumors are often dominated by pancreatic head enlargement, which can compress the portal vein, biliary system, etc. Clinically, abdominal pain and abdominal mass can occur.
Symptom
Pancreatic polypeptide tumor symptoms Common symptoms Abdominal pain Abdominal mass hypokalemia Diarrhea Vomiting
The clinical manifestations of PPoma have no significant relationship with excessive secretion of PP. Most of the PPoma cases have no obvious symptoms. Some patients with PPoma may present with WDHA syndrome, such as diarrhea (watery diarrhea or with steatorrhea), or light or heavy, individual Cases can be similar to watery diarrhea, hypokalemia, and low gastric acid syndrome in the case of VIP tumors. By measuring the PP and VIP in serum and tumor tissue, the blood PP is increased by more than 1000 times, while the VIP is not high, so PP is considered It can also cause watery diarrhea and lipid diarrhea. In addition, since PP cells are mainly distributed in the head of the pancreas, PP tumors are often mainly caused by pancreatic head enlargement, which can press the portal vein and biliary system to cause clinical symptoms. Abdominal pain and abdominal mass can occur.
Examine
Pancreatic polypeptide tumor examination
Serum PP radioimmunoassay is an important indicator for the diagnosis of this disease. The fasting serum PP level of patients with this disease is usually 20 to 50 times normal, and some even up to 700 times, but with the extensive development of PP radioimmunoassay, 30% is found. ~70% of various islet endocrine tumors may be associated with PP cell proliferation, peripheral blood PP concentration increased, suggesting that PP is a tumor marker for islet endocrine tumors, or PP cells appear to be early islet endocrine cells, with stem cell properties cell.
Positioning diagnosis can rely on B-ultrasound, CT, MRI and selective angiography to help understand the location, size, number and presence or absence of metastasis. Glaser et al. propose percutaneous transheptatic portal venour sampling. It is helpful to determine the location of PP production.
Diagnosis
Diagnosis and diagnosis of pancreatic polypeptide
Because PPoma has no special symptoms, it is difficult to diagnose. The diagnosis is mainly based on the determination of PP in the blood and immunohistochemistry. The cases of fasting serum PP are obviously increased. Regardless of whether there are clinical symptoms, there are indications for exploratory laparotomy. Examination of pituitary, thyroid, adrenal gland and other glands to avoid missed multiple endocrine neoplasia.
Glaser et al reported 2 elderly men with abdominal pain, vomiting, upper abdominal hernia and tumor mass, with liver metastasis, abnormal increase in PP in tumor tissues and peripheral blood, and other various digestive tract hormones were in the normal range. In cases of malignant PP cancer, pancreatic endocrine tumors that secrete only PP are also reported.
To be differentiated from other causes of elevated pancreatic polypeptide: vagus nerve excitability, meals, pseudo-pancreatic polypeptide, inflammatory bowel disease, renal failure and other pancreatic endocrine tumors such as insulinoma, gastrinoma, carcinoid syndrome , vasoactive intestinal peptide tumors, and the like.
