xxxxx 35. Neuroendocrine tumors of GIT or pancreaxxx Flashcards
neuroendocrine tumors of the gatsroinetsinal tract are mainly caused where ?
50 percent in the appendix vermiformis
then rectim
then ileum
jejunum
what so the neuroendocrine cells in the GIT release and what are the controlled by ?
somatostins made in the hypothalamus and gastroinetsinal tract = inhibting these neuroendocrine cells to release these hormones
hormones such as serotonins and histamine
bradykinin - vasodilator
prostaglandins
what are the signs and symtpoms of GIT carcinoids ?
carcinoid syndrome
flush and tachycardia and blood pressure fluctioations
diarrhea and colic like abdominal pain
asthma attack - serotonin causes bronchoconstrction
hedinger syndrome - right sided endocardiial fibrosis , with tricuspid insuffiency and pulmonary valve stenosis
how can we diagnose carcinoid tumors ?
increase 5 - hydroxy indol eacetic acid - ( degredation from the liver from serotonin) = 24 hr urine
increase serotonin in serum
chormagen A in serum increase
EUS
CT
MRI
somatostatin receptor scintography
what is the most common place for carcinoid tumors to metastsise to ?
liver - we find out metastasis to the liver is necessary for the CARCINOID SYNDROME TO OCCUR = liver dysfunction = less metabolsim of hormones such as serotonicn = so its effects comes about
symtpoms of gastroinetsinal carcinoid tumors can be worsened by ?
alcohol and emotional stress
what are the treatmnet for gastrointestinal carcinoid tumors ?
surgical resection
somatostatin analgoues
radiotherapy with radioactive somatostatin analogues
palliative chemotherapy
what are the two main neuroendocinr tumors of the pancreas ?
inuslinoma (mostly benign) and gastrinoma (mostly malignant) = zollinger ellison sydrome
what is the cause of zollinger ellison syndrome ?
occurs sporadically = 75 percent
or the rest by mutation of multiple endocrine neoplasia type 1
what are the symptos of zollinger ellison syndrome ?
peptic ulcers
inactivation of lipases by increasing the gastric acidity = diarrhea and steatorrhea
alnutrition
what is the diagnpsis of zollinger ellison syndrome ?
fasting gastrin levels on 3 seperate occasons
increased gastrin above 1000ng/l
secretin stimulation test = evoked gastrin levels (normal physiology secretin inhibits neuroendocrine cells hoever in gastrinoma cells it evokes it )
increased chromogranin a = tumor marker for carcinoid tumors
endoscopy of peptic ulcer , gastric ph decreased
CT scan
MRI
somatostatin receotor scintography
what is the treatment for zollinger ellison syndrome ?
curative tumor resection possible,
if there are no metastases
reduction of acid production: proton pump inhibitors
chemotherapy in metastasis
describe the charachteristics of insulinoma ?
benign with a diameter <2cm
larger insulinomas are most likely
malignant
mostly solitary
what are the symptoms for insulinoma ?
neuroglycopenic symptoms :
recurrent headache,
diplopia,
blurred vision particularly with exercise or fasting.
Severe hypoglycemia :
seizures,
coma,
and permanent neurological damage.
Symptoms resulting from the catecholaminergic response to hypoglycemia shaking , palpitations, tachycardia, sweating, hunger, anxiety,
what is the diagnosis of inulinoma ?
concomitant plasma glucose level of 45 mg/dL (2.5 mmol/L) or less, and
reversibility of symptoms with administration of glucose
serum glucose , insulin and c-peptide
A 72-hour fast, usually supervised in a hospital setting, can be done to see if insulin levels fail to suppress, which is a strong indicator of the presence of an insulin-secreting tumor.
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