gastrins and Somatostatinoma

Pancreatic neuroendocrine tumors (PNETs) are rare neoplasms representing <5% of all pancreatic malignancies with an estimated incidence of 1-1.5 cases/100,000. PNETs are broadly classified as either functional or nonfunctional. Functional PNETs include insulinomas, gastrinomas, vasoactive intestinal peptideomas, glucagonomas, and somatostatinomas. The clinical manifestations associated with these tumors are the result of excessive hormonal secretion and action. The functional nature of these tumors makes pancreatic hormone testing critical not only for initial diagnosis but also for follow-up, because they are important tumor markers. Nonfunctional PNETs typically remain clinically silent until a substantial mass effect occurs. Although the majority of PNETs occur sporadically, it is important to recognize that these tumors may be associated with a variety of familial syndromes and in many cases genetic testing of PNET patients is warranted. This article familiarizes the reader with the clinical presentation and the biochemical, radiologic, and genetic testing indicated for diagnosis and follow-up of patients with PNET.

Topics: Gastrinoma; Gastrins; Glucagon; Glucagonoma; Hormones; Humans; Hypoglycemia; Insulinoma; Neuroendocrine Tumors; Pancreatic Neoplasms; Somatostatinoma; Vasoactive Intestinal Peptide; Vipoma

Topics: Adenoma; Carcinoid Tumor; Endocrine System Diseases; Gastrins; Gastrointestinal Diseases; Glucagonoma; Histocytochemistry; Humans; Hyperinsulinism; Immunochemistry; Insulinoma; Islets of Langerhans; Pancreatic Diseases; Pancreatic Neoplasms; Peptic Ulcer; Somatostatinoma; Stomach; Vipoma

A case of duodenal somatostatinoma is described in a patient with Von Recklinghausen neurofibromatosis. The patient presented with exocrine pancreatic insufficiency, probably due to distal obstruction of the pancreatic duct by the tumor. Preoperative evaluation with calcium-pentagastrin and tolbutamide stimulation tests were nondiagnostic. At laparotomy, local excision of the tumor was performed. Pathological findings were compatible with duodenal somatostatinoma, causing pancreatic fibrosis. Somatostatin extracted from the tumor coeluted with the somatostatin-14 standard on high performance liquid chromatography (HPLC).

Topics: Adult; Biopsy; Chromatography, High Pressure Liquid; Duodenal Neoplasms; Exocrine Pancreatic Insufficiency; Female; Fibrosis; Gastrins; Glucagon; Humans; Microscopy, Electron; Neurofibromatosis 1; Pancreas; Pancreatic Polypeptide; Radioimmunoassay; Somatostatin; Somatostatinoma; Vasoactive Intestinal Peptide

We have evaluated the peripheral blood natural killer (NK) cell activity and the in vitro effect of recombinant gamma-interferon (r gamma-IFN) on NK cell activity in 23 patients with a neuroendocrine tumour of the pancreas, small intestine or liver, and 23 healthy controls. Patients with a gastrinoma showed a NK cell activity which was not different from that of the control group, whereas patients with another type of neuroendocrine tumour had a decreased NK cell activity compared to the controls (p less than 0.05) and the gastrinoma patients (p less than 0.02). The impaired NK cell activity in these patients was as such not related to the presence of liver metastasis or performance status of the patients. r gamma-IFN significantly stimulated the NK cell activity in patients and controls. However, the cytotoxic response of the patients with a hormone production other than gastrin remained lower than in the two other groups. Follow-up studies in 8 patients showed NK cell activities not to vary with stable disease, to decrease with progressive disease, and to increase with regression of disease. In conclusion, NK cell activity is suppressed in patients with neuroendocrine tumours that produce hormones other than gastrin. This impairment is not related to the presence of metastasis but seems to be related to the course of the disease.

Topics: Adult; Aged; Carcinoid Tumor; Cell Line; Female; Gastrinoma; Gastrins; Gastrointestinal Hormones; Humans; Interferon-gamma; Intestinal Neoplasms; Killer Cells, Natural; Lipoma; Liver Neoplasms; Male; Middle Aged; Pancreatic Neoplasms; Recombinant Proteins; Somatostatinoma; Tumor Cells, Cultured

We studied a patient with a very small somatostatinoma that arose from the prominence of the orifice of the duct of Santorini. The patient presented clinically with epigastric discomfort, marked loss of weight, diarrhea, exertional dyspnea, and chest pain. He flushed intermittently and had occasional tachycardia and hypertension. Levels of serum serotonin and urinary 5-hydroxyindoleacetic acid were normal. A small ampullary tumor was resected and identified by immunohistochemical staining to be a somatostatinoma. The patient had gained 6.75 kg and was essentially free of symptoms 16 months after surgery.

Topics: Adenoma, Islet Cell; Gastrins; Humans; Male; Middle Aged; Neoplastic Stem Cells; Pancreatic Ducts; Pancreatic Neoplasms; Serotonin; Somatostatin; Somatostatinoma