These are functional tumours, normally producing several hormones. However they are classified on the basis of the main hormone produced which causes the majority of attributable symptoms. There is now evidence that early and aggressive screening using endoscopic ultrasound can identify pancreatic endocrine tumours in those asymptomatic patients with MEN-1. This earlier detection of tumours may in the future facilitate prompt surgical intervention and improve the prognosis.
This is the most common pancreatic tumour in MEN 1 making over 50% of pancreatic tumours in the syndrome. It secretes mainly gastrin. Increased gastrin levels cause excess acid production by the stomach causing the formation of ulcers in the stomach and duodenum which may perforate and bleed in time. Irritation of the intestine also causes diarrhoea. This is also known as Zollinger-Ellison syndrome.
The hyperparathyroidism of MEN 1 may also cause increased gastrin levels. Diagnosis must therefore be made carefully, normally involving a secretin stimulation test (see pancreas section).
Gastrinomas are treated medically by blocking acid production using the drugs omeprazole or ranitidine. Cure is only by surgical removal of the tumours and is possible in only 10-15% of cases.
Making up about a third of pancreatic tumours in MEN 1, these are tumours secreting predominantly insulin, a hormone that lowers blood glucose. They therefore cause symptoms due to low blood sugar (hypoglycaemia). These include confusion, blurred vision, seizures and potentially coma. Occasionally tremors, sweating, palpitations, headache and nausea may occur.
The best treatment is surgery to remove the tumour when possible. Medical treatment is also used to control symptoms before surgery and in cases where surgery is not possible. Chemotherapy can also be used for malignant tumours to improve symptoms and survival.
These are extremely rare. They are tumours secreting predominantly glucagon, a hormone that raises blood glucose levels. Symptoms include a characteristic itchy rash (necrolytic migratory erythema), weight loss and anaemia.
Optimal treatment is again surgery to remove the tumour. The drug octreotide can be used to control symptoms and chemotherapy may also be used.
These are very, very rare tumours secreting VIP (vasoactive intestinal polypeptide). This excess VIP causes diarrhoea, low blood potassium levels and low acid production by the stomach.
Surgery is the best treatment to remove the tumour. Octreotide and chemotherapy may again be used to control symptoms and slow tumour growth.
These are tumours secreting excess pancreatic polypeptide (PP). They arise quite commonly in people with MEN 1. No clinical symptoms arise, but the diagnosis of raised blood PP has been suggested as a screening tool for the detection of pancreatic tumours in MEN 1.
For much more information on pancreatic tumours and pancreatic physiology please see the relevant parts of the 'Pancreas' section of this website.