Approximately 60-80% of VIPomas are malignant
and have metastasized at the time of diagnosis. Metastasis occurs most frequently in the liver but may also occur in the lymph nodes, lungs, or kidneys. Approximately 5% of VIPomas are associated with multiple endocrine neoplasia (MEN) type 1 syndrome.
What causes high VIP levels?
A very high level is usually caused by
a VIPoma
. This is an extremely rare tumor that releases VIP. VIP is a substance found in cells throughout the body. The highest levels are normally found in cells in the nervous system and gut.
What is VIP disease?
A vipoma is
a non-beta pancreatic islet cell tumor secreting vasoactive intestinal peptide
(VIP), resulting in a syndrome of watery diarrhea, hypokalemia, and achlorhydria (WDHA syndrome). Diagnosis is by serum VIP levels. Tumor is localized with CT and endoscopic ultrasound. Treatment is surgical resection.
How does VIP cause diarrhea?
VIP is a 28 amino acid polypeptide that binds to high affinity receptors on intestinal epithelial cells, leading to activation of cellular adenylate cyclase and cAMP production. This results
in net fluid and electrolyte secretion into the lumen
, resulting in secretory diarrhea and hypokalemia [6,7].
Why does VIP cause achlorhydria?
There is also bicarbonate wasting through stool, leading to hypokalemic nonanion gap metabolic acidosis (15). Hypochlorhydria or achlorhydria is typically
due to the inhibitory effect on parietal cells of gastric mucosa
, resulting in reduced gastric acid production (16).
What does VIP do to your body?
VIP
stimulates the secretion of ductal pancreatic and biliary bicarbonate and water
and simultaneously inhibits gastric acid and pepsinogen secretion as well as absorption from the intestinal lumen. VIP also stimulates enzyme secretion from pancreatic acinar cells and regulates chloride secretion.
What is a VIP OMA?
A vipoma is a
non-beta pancreatic islet cell tumor secreting vasoactive intestinal peptide
(VIP), resulting in a syndrome of watery diarrhea, hypokalemia, and achlorhydria (WDHA syndrome).
Is VIPoma treatable?
Initial
treatment
of VIPomas is directed toward correcting volume and electrolyte abnormalities. Octreotide acetate controls diarrhea in up to 90% of patients with VIPomas. Glucocorticoids reduce symptoms in 50%. Systemic chemotherapy may be needed in cases of unresectable or progressive disease.
Is VIPoma hereditary?
This is often a
genetic condition
that runs in families. VIPoma: A type of neuroendocrine pancreatic tumor that secretes vasoactive intestinal polypeptide (VIP).
How is Somatostatinoma diagnosed?
- somatostatinoma blood test.
- CT scan.
- MRI scan.
- endoscopic ultrasound.
- somatostatin receptor scintigraphy.
Why does VIPoma cause watery diarrhea?
This occurs as a result of
VIP binding to intestinal epithelial cells, thereby upregulating cAMP and leading to secretion of electrolytes into the bowel lumen
, causing profuse watery diarrhea [2].
How is VIPoma diagnosed?
Tests used to diagnose a VIPoma may include
blood tests (including VIP level), imaging studies such as a CT scan or MRI , and examination of a stool sample
. Unfortunately, even though these tumors are slow-growing, the majority of VIPomas are metastatic (have spread to other parts of the body) at the time of diagnosis.
How does Gastrinoma cause diarrhea?
These tumors, called gastrinomas, secrete large amounts of the hormone gastrin, which causes your stomach to produce
too much acid
. The excess acid then leads to peptic ulcers, as well as to diarrhea and other symptoms.
What does insulinoma mean?
An abnormal mass that grows in the beta cells of the pancreas that make insulin
. Insulinomas are usually benign (not cancer). They secrete insulin and are the most common cause of low blood sugar caused by having too much insulin in the body.
What is Glucagonoma?
Glucagonoma is
a very rare tumor of the islet cells of the pancreas
, which leads to an excess of the hormone glucagon in the blood.
What does elevated chromogranin A mean?
CgA levels may be elevated in conditions such as
liver disease
, inflammatory bowel disease, pancreatitis, chronic bronchitis, renal insufficiency, and stress. These possible causes for elevated CgA levels should be considered when interpreting test results.
