LUKOIL lets contracts for Perm refinery's proposed FCC complex

Abstract

Pancreatic neuroendocrine tumors (PNETs) were formerly termed pancreatic islet tumors. These are rare tumors, comprising 2%–3% of all pancreatic tumors. They derive from pluripotent pancreatic stem cells. PNETs can be classified as functional and nonfunctional. Functional tumors secrete hormones that result in a specific clinical presentation. Insulinomas are the most common PNETs. They are usually benign. Glucagonomas and VIPoma are most commonly malignant. Surgical resection, surgical debulking ± systemic treatment may be used. The Zollinger-Ellison syndrome (ZES) is characterized by gastric acid hypersecretion leading to severe acid-related peptic ulcer disease with diarrhea, caused by a gastrinoma, also a neuroendocrine tumor. The gastrinoma triangle (sweep of duodenum/head of pancreas) is the location of 80% of these tumors. The majority of gastrinomas are located in the duodenum. Gastrinomas may be associated with MEN1 (hyperparathyroidism, pituitary tumors, and gastrinoma) in 20% of cases. Surgical resection is the primary treatment of choice for sporadic gastrinoma. Enucleation of small pancreatic tumors, duodenotomy, and enucleation of small duodenal tumors are the most common procedures performed. Liver resection, hepatic artery embolization and/or chemoembolization, microsphere embolization, radiofrequency or cryoablation, and liver transplantation all have been utilized for metastatic disease.