RT Book, Section
A1 Melcescu, Eugen
A1 Koch, Christian A.
A2 Murray, Michael F.
A2 Babyatsky, Mark W.
A2 Giovanni, Monica A.
A2 Alkuraya, Fowzan S.
A2 Stewart, Douglas R.
SR Print(0)
ID 1102700667
T1 Pancreatic Neuroendocrine Tumors
T2 Clinical Genomics: Practical Applications in Adult Patient Care
YR 2014
FD 2014
PB McGraw-Hill Education
PP New York, NY
SN 9780071622448
LK accessbiomedicalscience.mhmedical.com/content.aspx?aid=1102700667
RD 2024/04/20
AB Disease  summary:Pancreatic  neuroendocrine  tumors  (PNETs)  are  uncommon  and  represent  only  1%  to  2%  of  pancreatic  neoplasms,  about  85%  of  these  tumors  occur  in  the  pancreas  and  15%  are  extrapancreatic  tumors.Based  on  their  clinical  expression  these  tumors  are  categorized  as  either  functional  or  nonfunctional.Functional  tumors  (~50%)  are  characterized  by  abnormal  secretion  of  (often)  biologically  active  peptides  mostly  insulin,  gastrin,  glucagon,  somatostatin,  or  vasoactive  intestinal  polypeptide  (VIP).Nonfunctional  tumors  are  clinically  silent  although  they  can  secrete  neurotensin,  pancreatic  polypeptide  or  chromogranin  A  (CgA),  but  these  peptide-like  substances  are  not  biologically  active.  Most  nonfunctional  PNETs  have  a  malignant  course.  They  are  discovered  usually  when  their  size  is  large,  have  already  invaded  adjacent  organs  or  metastasized.Among  functional  tumors,  insulinomas  and  gastrinomas  account  for  25%  and  15%  of  the  cases,  respectively.  The  other  functional  PNETs  are  responsible  for  the  remaining  15%.Negative  prognostic  factors  for  PNETs  are  considered:  metastasis,  tumor  diameter,  angioinvasion,  proliferative  index  Ki-67,  lymph  nodes,  and  mitoses.  Localized  disease  has  a  5-year  survival  rate  of  60%  to  100%,  whereas  regional  and  metastatic  PNETs  have  a  40%  and  29%  survival  rate,  respectively.