Hormone-active pancreatic tumors: causes, symptoms, diagnosis, treatment

Most hormone-active tumors of the digestive system are localized in the pancreas. This is due to the abundance of hormone-competent cells in it, from which such tumors originate. The first report on adenocarcinoma of pancreatic islets, flowing with symptoms of hypoglycemia (about a tumor named later insulinoma), was made in 1927. RM Welder et al. Currently, there are already 7 clinical syndromes caused by the development of pancreatic tumors that produce various hormones.

Cells from which hormone-producing pancreatic tumors originate belong, according to the concept of F. Feyrter (1938), to the diffuse endocrine system, according to the hypothesis of AG E. Pearse (1966), to the APUD-cell system. The term is the acronym for the words Amino Acid Precursor Uptake and Decarboxylation, meaning the ability of cells to capture from the environment the precursors of biogenic amines and decarboxylate them. By now the understanding of the term has changed. Biochemical properties encoded with the letters APUD are not mandatory for APUD cells. Now the term "APUD-system" is understood as the types of cells capable of secreting biologically active amines or polypeptides and proteins and accumulating them in endoplasmic granules with specific ultrastructural and cytochemical properties.

Tumors that arise from the cells of the APUD system are called apodomas. They are extremely heterogeneous in structure. Most often, apodomas synthesize products characteristic of normal apodocytes of the corresponding localization - orthoendocrine apodomas, according to R. W. Welbourn (1977). An example is a pancreatic tumor of insulinoma. Often, substances that are not inherent in the normal endocrine cells of this organ (para- endocrine apodomas) are produced in apodomas. So, there are pancreatic tumors producing ACTH and / or ACTH-like substances, which leads to a clinical picture of Cushing's syndrome. Perhaps the almost simultaneous or sequential development of hormone-active tumors of various organs both inside and outside the digestive tract (multiple endocrine adenomatosis).

Endocrine tumors of the digestive system are called, if possible, according to the hormonal product produced by them. In cases where the suspected hormone is not proven or is supposed to secretion by the tumor of several hormonal substances that determine the clinical picture of the disease, it is designated descriptively.

Endocrine tumors of the pancreas are found in various parts of it. Clinical manifestations arise, as a rule, at a tumor value of more than 0.5 cm. Initially, the symptoms of metabolic disorders caused by hormonal excess appear more often, and only later - the clinical manifestations of the affected organ. Endocrine tumors of the pancreas are benign and malignant. The larger the size, the more often they metastasize. Metastases are also predominantly hormone-active.

Diagnosis of an adulum includes two tasks: to establish the localization of the tumor, and in case of a pancreatic lesion-to clarify the intraorganic location of the pancreas, for this determines the tactics of the surgical intervention; to establish the hormonal substance produced by the tumor, which is necessary for conducting adequate conservative treatment.

Prove the production of tumor specific hormone was made possible by the creation and introduction into practice of radioimmune methods of investigation, specific and highly sensitive. With the secretion of the hormone by cells of an apodoma into the blood, you can determine its elevated plasma content. Diagnosis is also helped by immunocytochemical examination of biopsy specimens from organs obtained with preoperative biopsy (or intraoperatively). In some cases, identification of endocrine cells in a tumor is also possible by determining typical secretory granules by electron microscopy.

If a pancreas tumor is suspected, CT, ultrasound, scintigraphy, selective angiography of the celiac trunk and the superior mesenteric artery are used. With a tumor size of 1 cm or more, as a rule, it is possible to establish its localization. To clarify the diagnosis apply puncture biopsy of the pancreas under ultrasound or radiographic during CT with a subsequent histological, immunocytological study. In case of doubt, to clarify the intrapancreatic localization of the endocrine tumor, percutaneous transhepatic catheterization is carried out for draining the pancreas of the veins - the spleen, pancreatoduodenal, superior mesenteric - with blood sampling to determine the concentration of a particular hormone. High hopes are placed on the endoscopic ultrasound developed in recent years. Endoscopy retrograde pancreatography is effective only when the tumor leads to changes in the pancreatic system (for example, to stenosis, obstruction).

Radical treatment is only surgical. The superficially located adenoma, especially when localized in the gland's head, is enucleated. In case of deeper localization of the tumor, the volume of the operation is increased, the resection of the corresponding gland section is applied, up to the partial duodenopan-creaectomy. With a malignant tumor and the impossibility of radical removal of it, a palliative intervention is performed: to reduce the mass of the secreting tissue, the tumor and metastases as far as possible are eliminated as much as possible.

With preoperative management of patients, with the tumor location not yet established, pharmacological symptomatic treatment is prescribed, and inoperable patients and patients with common metastases that can not be removed are additionally treated with cytostatic therapy.

[1], [2], [3], [4], [5]