endocrine and metabolic disorders
Multiple Endocrine Neoplasia, Type 4 (MEN 4)
Diagnosis of MEN 4
Serum calcium,parathyroid hormone(PTH), gastrin, and prolactin levels Diagnosis of MEN 4 follows the same approach as for Diagnosis and includes blood testing for hormone excess and genetic testing to identify the causative mutation in the Initial laboratory studies include serum calcium,parathyroid hormone, gastrin, and prolactin levels. Additional laboratory or radiologic tests may be needed if these tests suggest an endocrine abnormality related to MEN 1. A gastrin-secreting gastroenteropancreatic neuroendocrine (GEP-NET) tumor of the pancreas or duodenum is diagnosed by elevated basal plasma gastrin levels, an exaggerated gastrin response to infused calcium, and a paradoxical rise in gastrin level after infusion ofsecretin. Aninsulin-secreting beta-cell tumor of the pancreas is diagnosed by detecting fasting hypoglycemia with an elevated plasmainsulinlevel. An elevated basal level of pancreatic polypeptide or gastrin or an exaggerated response of these hormones to a standard meal may be the earliest sign of pancreatic involvement. Gigantism and Acromegaly is diagnosed by elevated growth hormone levels that are not suppressed by glucose administration and by elevated levels of serum Ultrasonography or computed tomography (CT) can help localize tumors. Because these tumors are often small and difficult to localize, other imaging tests (eg, helical [spiral] CT, angiography, MRI, endoscopic ultrasonography, intraoperative ultrasonography) may be necessary. Thoracic imaging with fluorine-18 [18F]–labeled deoxyglucose (18F-FDG) orgallium Ga 68 dotatatepositron emission tomography (PET)/CT may be useful in distinguishing bronchopulmonary neuroendocrine tumors from benign pulmonary nodules and in identifying thymic carcinoid. For pancreatic and duodenal neuroendocrine tumors,gallium Ga 68 dotatatepositron emission tomography/CT was threefold more sensitive thanoctreotidescanning or CT scanning in a study of multiple imaging modalities in 26 cases of MEN 1; when available, this test should replaceoctreotidescanning for periodic imaging. 