An insulinoma is a rare tumour which develops in the islet cell of the pancreas. There are about 100 new cases diagnosed each year in the UK.

The islet cells make the hormone insulin and so insulinomas lead to high levels of insulin, and low levels of sugar, in the blood. This causes episodes of headache, sweating, palpitations weakness and even seizures or loss of consciousness. These episodes most commonly occur first thing in the morning, on exercise or after missing a meal. They are relieved by eating food or drinking sugary drinks.

The cause of most insulinomas is not known but about 1 in 20 of them is associated with an inherited condition, called MEN1 (multiple endocrine neoplasia 1), where tumours can occur in a number of hormone-producing glands.

Insulinomas usually occur in middle age, but those linked to MEN1 often affect people in their mid 20s. The tumours are more common in women than men. 9 out of 10 insulinomas are benign (non-cancerous). Usually they develop as a single, small tumour (less than 2cm across) on the surface of the pancreas, but occasionally they appear as multiple tumours. The rare cases that are malignant tend to spread to send seedlings of tumour (secondary cancers) to the liver.

Blood tests measuring insulin and blood sugar levels usually confirm the diagnosis. X-rays and scans may be done as well but as the tumours are usually small they often do not show up on these tests.

The cornerstone of treatment for insulinomas is surgery. As the tumours are usually small, and on the surface of the pancreas, the operation is normally very simple and straightforward, and can be done without damaging the rest of the pancreas. The surgery will bring about a complete cure in more than 9 out 10 people with an insulinoma.

For people who refuse surgery, or who have tumours where surgery might be difficult (for example cancerous tumours that have spread, or multiple tumours throughout the pancreas) drugs like diazoxide and ocreotide can be given to help control the symptoms caused by the tumour but they will not result in a cure.

So for a solitary benign insulinoma the best advice is to go ahead with surgery, unless your doctors feel there is some special reason why this would not be advisable in your case.