Histological and Histochemical Description of the Pancreas in the Adult Lesser Capybara (Hydrochoerus isthmius)

The aim of this study was to describe histologically and histochemically the pancreas of three adult Hydrochoerus isthmius, attacked by feral dog in Buenavista, Córdoba, Colombia. A complete necropsy was performed and pancreatic fragments were collected and stored in 10% buffered formalin and Bouin liquid. Then, they were dehydrated, diaphanized and embedded in paraffin, stained with Hematoxylin & Eosin, P.A.S., Gomori trichrome, Grimelius and Masson Fontana modified. The H. isthmius pancreas presented a duodenal mesenteric pattern. The exocrine portion was described as a composite tubuloacinar gland. The endocrine portion of the pancreas was constituted by pancreatic islets of Langerhans and a diffuse neuroendocrine system. The histological and histochemical techniques used allowed us to identify the exocrine and endocrine portion of the organ. It is suggested to complement this study with some special techniques for the identification of specific endocrine cells, such as Beta, Alpha, Delta, Epsilon, PP or Gamma.

Small-Cell Carcinoma of Nasopharynx: A Case Report of Unusual Localization

Neuroendocrine tumors are a spectrum of rare and highly heterogeneous neoplasms with distinct functional and biological behavior in relation to location, tumor size, and histological differentiation. Neuroendocrine tumors arise from the neuroendocrine cells of the diffuse neuroendocrine system located in almost every organ. Neuroendocrine tumors in the head and neck district are usually reported in sinonasal cavities and larynx. We present the case of a nasopharyngeal small-cell neuroendocrine carcinoma, which, as far as we know, is the 16th case reported in literature.

Specific and Non-Specific Biomarkers in Neuroendocrine Gastroenteropancreatic Tumors

The diagnosis of neuroendocrine tumors (NETs) is a challenging task: Symptoms are rarely specific, and clinical manifestations are often evident only when metastases are already present. However, several bioactive substances secreted by NETs can be included for diagnostic, prognostic, and predictive purposes. Expression of these substances differs between different NETs according to the tumor hormone production. Gastroenteropancreatic (GEP) NETs originate from the diffuse neuroendocrine system of the gastrointestinal tract and pancreatic islets cells: These tumors may produce many non-specific and specific substances, such as chromogranin A, insulin, gastrin, glucagon, and serotonin, which shape the clinical manifestations of the NETs. To provide an up-to-date reference concerning the different biomarkers, as well as their main limitations, we reviewed and summarized existing literature.

Radionuclide imaging and therapy in patients with neuroendocrine tumors

Neuroendocrine tumors (NETs) are heterogeneous group of the tumors that arise from the enterochromaffin cells of the diffuse neuroendocrine system and occurr in 0.5% of all neoplasms. Recently there has been a significant increase in the incidence of neuroendocrine tumors, which is undoubtedly associated with the improvement of diagnostic methods. However, despite significant success in studying the biological and molecular mechanisms of its behavior, a single algorithm for the diagnosis and treatment of neuroendocrine tumors remains unclear today. Treatment of neuroendocrine tumors largely depends on their functional status and the stage of the disease. While the treatment of localized NETs is surgical resection, varieties of therapeutic options are available for patients with advanced NETs. These include medical control of excess hormone levels and associated symptoms, cytoreductive surgery for patients with advanced disease, systemic chemotherapy, somatostatin analogues, and peptide receptor-targeted radionuclide therapy. However, the right choice of the therapeutic approach in current clinical practice in heterogeneous group of patients with neuroendocrine tumors requires further discussion.

The role of diffuse neuroendocrine system of the digestive tract in the development of disorders of proliferation and apoptosis in the stomach of patients with Helicobacter pylori infection

In the implementation of oncogenesis and, in particular, the cascade of Correa, a significant role is played by the relationship of proliferation and apoptosis with the system functioning of the digestive tract of the diffuse neuroendocrine system and Helicobacter pylori