Gastro Flashcards
What is the characteristic endoscopy finding in Gastric Antral Vascular Ectasia?
Watermelon stomach - longitudinal rows of flat, reddish stripes radiating from the pylorus into the antrum that resemble the stripes on a watermelon
Are there any conditions associated with GAVE?
It is usually an isolated condition but may be associated with cirrhosis or systemic sclerosis
What patient demographic is GAVE most commonly found in?
Older (>70yo) women (80%)
How do you diagnose Gastric Antral Vascular Ectasia?
Based on classical endoscopic appearance.
Diagnosis may be confirmed by endoscopic biopsy, endoscopic ultrasound, tagged red blood cell scan, or computed tomography (CT) scan
What are the histopathological characteristics of GAVE?
vascular ectasia, spindle cell proliferation, and fibrohyalinosis
How might GAVE present?
Usually as chronic GI bleed causing iron deficiency anaemia.
However it may present with an acute upper GI bleed
How do you treat GAVE?
Periodic blood transfusions
+
Endoscopic coagulation with a heater probe, bipolar probe, argon plasma coagulator, laser therapy, or radiofrequency ablation - these can obliterate the vascular ectasia and decrease the degree of bleeding
Does portal decompression with TIPS reduce bleeding in GAVE?
No, underscoring the uncertain relationship between GAVE and portal hypertension
Other than endoscopic therapies, what other treatments can be tried for refractory GAVE?
Combination oestrogen-progesterone therapy
Or
Antrectomy
What is Zollinger-Ellison syndrome?
ZE refers to the syndrome of gastric acid hypersecretion by a duodenal or pancreatic neuroendocrine tumour (which secretes gastrin - ie a gastrinoma) that results in severe acid-related peptic disease and diarrhoea
Is Zollinger-Ellison syndrome more common in males or females?
Males
Commonly diagnosed between age 20-50
What autosomal dominant predisposition to tumors is associated with Zollinger-Ellison syndrome?
Multiple endocrine neoplasia type 1 (MEN1)
It is classically associated with the “3 Ps”
- parathyroid glands
- pituitary gland (anterior)
- pancreatic endocrine cells
But many other types of cancers recognised to be increased in this condition
What are the 3 Ps of Multiple Endocrine Neoplasia type 1 (MEN1)?
Refers to classical tumour location that patients with MEN1 are predisposed to:
- Parathyroid gland
- Pituitary gland (anterior)
- Pancreatic endocrine cells
What percentage of Zollinger-Ellison syndrome is linked to MEN1?
20-30%
The rest are sporadic
What percentage of gastrinomas arise in the pancreas?
20-25%
The rest are in the duodenum - mostly D1
What are some of the differences between duodenal and pancreatic gastrinomas?
Duodenal gastrinomas tend to be:
- small (<1cm)
- multiple
- less likely to have metastasised to liver at diagnosis
In what percentage of patients with gastrinomas do the gastrinomas arise from sites other than the pancreas or duodenum? Where may they arise?
5-15%
Can arise from stomach, peripancreatic lymph nodes, liver, bile duct, ovary, heart, small cell lung ca
How are neuroendocrine tumours arising from the digestive system classified by the WHO?
Based on the extent to which they resemble their normal non-neoplastic counterparts
If a neuroendocrine tumour stains for gastrin and secretes gastrin but does not produce symptoms of Zollinger-Ellison syndrome, is it a gastrinoma?
No - the designation of the tumor as a gastrinoma is based upon the presence of a clinical syndrome that results from tumor production and secretion of gastrin, and not by its morphologic appearance or the presence of gastrin in the secretory granules
In many cases, whilst the tumour may secrete gastrin, the hormone is not processed to biologically active gastrin
What is the pathophysiology of Zollinger-Ellison syndrome?
In ZE syndrome, gastrinomas secrete excessive gastrin which results in high gastric acid output due to the trophic actions of gastrin on parietal cells and histamine-secreting enterochromaffin-like cells
Why do patients with Zollinger-Ellison syndrome experience chronic diarrhoea?
The high volume of gastric acid secreted cannot be fully reabsorbed in small and large intestines
It also exceeds the neutralising capacity of pancreatic bicarbonate secretion resulting in exceptionally low intestinal pH which inactivates digestive enzymes and the emulsification of fat as well as damaging intestinal epithelial cells and villi resulting in malabsorption
The high serum gastrin concentration also inhibits sodium and water reabsorption by the small intestine leading to a component of secretory diarrhoea
What are the main clinical manifestations of Zollinger-Ellison syndrome?
Peptic ulcer disease
Heartburn
Diarrhoea
Weight loss
Complications of acid hypersecretion including bleeding, stricture fistulisation
In <10% - especially those with metastatic disease or MEN1 - may have symptoms due to second hormonal syndrome eg VIPoma
What percentage of gastrinomas are malignant?
60-90%
Are there any features on endoscopy that may raise suspicion for Zollinger-Ellison syndrome?
Ulcers are more likely to be refractory to PPI therapy and more likely to recur than in patients with sporadic ulcer disease
Ulcers often occur in unusual locations e.g. beyond the first or second fold of the duodenum
90% of patients with Zollinger-Ellison syndrome have prominent gastric folds