1/5. Overview of chronic diarrhea caused by functional neuroendocrine neoplasms.Eight different neoplastic disorders can cause chronic diarrhea attributable to humoral-mediated diarrhea. These include pancreatic endocrine tumor (PET) syndromes (gastrinomas, VIPomas, glucagonomas, somatostatinomas, PET's releasing calcitonin), carcinoid syndrome, medullary thyroid cancer, and systemic mastocytosis. Because these disorders are an uncommon cause of all chronic diarrheas (<1%), they are not often considered in the differential diagnosis, leading to a delay in diagnosis. This is problematic not only because all are treatable, but also because the neoplasm is frequently malignant. In this article, the characteristics and pathogenesis of the diarrhea, important clinical and diagnostic laboratory features, and treatment of each disorder are briefly reviewed, with an emphasis on recent insights.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
2/5. Are pancreatic VIPomas paraneuron neoplasms? A clue to the neuroectodermal origin of these tumors.Three pancreatic vasoactive intestinal polypeptide (VIP)-producing tumors associated with the watery diarrhea-hypokalemia-achlorhydria syndrome were studied histologically, ultrastructurally, and immunocytochemically. All the tumors contained varying numbers of cells arranged in pseudoglandular structures. The cells showed a polar organization, with apical tuft of microvilli and basal VIP-containing, synaptic vesicle-like granules. Based on the morphology of the vipoma cells typical of recepto-secretory cells, together with the ability to synthesize and release a peptide that in normal conditions is expressed exclusively by neurons, and the absence of VIP-producing endocrine cells in normal pancreas and gastrointestinal mucosa, the hypothesis is drawn that the pancreatic VIPomas reported here are paraneuron neoplasms, which possibly originate from neuroectodermal ancestors.- - - - - - - - - - ranking = 1keywords = neoplasm (Clic here for more details about this article) |
3/5. Laparoscopic distal pancreatectomy for neuroendocrine tumors of the pancreas.Although neuroendocrine tumors of the pancreas are traditionally managed by laparotomy, these rare neoplasms may be amenable to laparoscopic surgical resection. We present our experience with laparoscopic distal pancreatectomy in two such patients, and discuss the operative technique with emphasis on organ preservation. Two female patients aged 63 and 69 years presented with clinical and biochemical features of an insulinoma and a vasoactive intestinal peptide secreting tumor (vipoma), and were found on cross-sectional imaging to have 1.2-cm and 4.5-cm solitary tumors in the tail of the pancreas. They underwent laparoscopic distal pancreatectomy with and without preservation of splenic vessels and spleen respectively. Both procedures were completed laparoscopically. The operating time was 180 and 210 minutes respectively. There were no postoperative complications. The postoperative hospital stay was 4 and 14 days respectively. histology revealed a benign insulinoma and a malignant vipoma with lymph node metastases respectively. Laparoscopic distal pancreatectomy for neuroendocrine tumors of the pancreas may be accomplished safely, with preservation of the spleen and splenic vessels in benign disease, and with benefits to the patients in terms of postoperative recovery.- - - - - - - - - - ranking = 0.2keywords = neoplasm (Clic here for more details about this article) |
4/5. Giant metastatic vipoma in the liver.A case of giant metastatic liver vipoma manifesting WDHA syndrome is described. The patient was a 33-year-old Japanese male who was admitted because of persisting watery diarrhea and weight loss. Laboratory examinations revealed marked hypokalemia, mild hypercalcemia and highly elevated plasma vasoactive intestinal peptide (VIP) and glucagon levels. Intensive imaging examinations disclosed two large tumors in the liver but not in other organs, including the pancreas. laparoscopy disclosed a slightly elevated purplish-colored large tumor on the surface of the apparently normal liver. At operation, however, a small hard nodule was observed in the tail of the pancreas. Histologically, it was revealed to be a vipoma resembling a carcinoid or an islet cell tumor, and was identical to the liver tumors. Thus, this neoplasm was considered to be a vipoma of pancreatic origin, with metastatic lesions in the liver.- - - - - - - - - - ranking = 0.2keywords = neoplasm (Clic here for more details about this article) |
5/5. Neuroendocrine gut neoplasms. Important lessons from uncommon tumors.OBJECTIVE: To review our experiences in order to high-light some important lessons learned in the treatment of patients with neuroendocrine gut neoplasms. DESIGN: Retrospective analysis of case series of 70 patients with neuroendocrine gut neoplasms treated between 1983 and 1993. The clinical features of individual patients illustrate lessons in surgical treatment. SETTING: University hospitals with tertiary care referral practice. INTERVENTIONS: The main intervention was abdominal exploration in 43 patients, with resection of the primary tumor in 39 and of hepatic metastases in four. MAIN OUTCOME MEASURES: To describe the tumors seen and to identify major lessons learned. RESULTS: Of 70 patients with neuroendocrine tumors treated, 31 had carcinoid tumors, 10 each had insulinomas and gastrinomas, five had vipomas, nine had non-functioning islet cell tumors, three had glucagonomas, and one each had somatostatinoma and a possible cholecystokinin-secreting tumor (or CCKoma). Important lessons learned include: (1) the importance of preoperative tumor localization; (2) in multiple endocrine neoplasia, type I syndrome, the tumor found may not be the one responsible for the patient's symptoms; (3) solitary sporadic tumors secreting multiple peptides may mimic multiple tumors in multiple endocrine neoplasia, type I syndrome; (4) one needs to be prepared for the unexpected, such as the carcinoid crisis; (5) resection may sometimes be necessary even with advanced local disease; and (6) selected patients may benefit from pancreaticoduodenectomy. CONCLUSIONS: These rare tumors are interesting in their clinical presentation and can be challenging in their treatment.- - - - - - - - - - ranking = 1.2keywords = neoplasm (Clic here for more details about this article) |