There are several diagnostic tests for Carcinoid tumor. Before your doctor can make a firm diagnosis of a carcinoid tumour a number of tests will have to be done.

Urine test When serotonin is broken down in the liver, it is excreted as a chemical called 5HIAA in the urine. Your urine will be collected over a 24-hour period to check whether there are raised levels of 5HIAA.

Blood tests may be taken to check serotonin levels.The doctor may also carry out a number of tests to find out whether the cancer has spread.

X-rays and scans These may be taken to show if there has been any spread of the tumour.

Chest x-ray This will show whether there has been any spread to the lungs.

Ultrasound scan A simple, painless scan which uses sound waves to form a picture of the inside of the abdomen.

CT (computerised tomography) scan A CT scan takes a series of x-rays to build up a three-dimensional picture of the inside of the body. The scan is painless but takes longer than an x-ray (about 30 minutes). It may be used to find where the cancer started (the primary tumour) or to check for any spread of the disease (secondaries or metastases).

MRI (magnetic resonance imaging) scan This scan uses magnetism instead of x-rays to form a series of cross-sectional pictures of the inside of the body. During the scan you will be asked to lie very still on a couch inside a metal cylinder. The test can take up to an hour and is completely painless, although the machine is quite noisy. If you don’t like enclosed spaces you may find the machine claustrophobic.

Octreotide scan An octreotide scan examines how several of your internal organs are working. Octreotide is a substance that is absorbed by carcinoid cells. It can show where a cancer started and any areas that it has spread to. The scan is done in the nuclear medicine department and takes place over three consecutive days. On the first day you will go to the department twice. In the morning you will have an injection in your arm. You are then usually free to stay in or leave the hospital. In the afternoon you will have a scan taken using a gamma camera. The scan takes about an hour and during this time you will lie still on a bed. On the following two afternoons pictures will again be taken for up to one and a half hours.

123MIBG scan A drug called 123MIBG may be used to show up the site of a carcinoid tumour. 123MIBG is a mildly radioactive drug that is absorbed by carcinoid cells. The scan takes place over two consecutive days in the nuclear medicine department. On the first day you will go to the department twice. In the morning you will be given an injection in the arm. You are then usually free to stay or leave the hospital. You will go back to the department in the afternoon to have a scan with a gamma camera lasting for about an hour. The following morning you will have further pictures taken for about one and a quarter hours. At this point you may be given a further injection of 123MIBG.

Biopsy A small sample of cells is taken from the tumour to be examined under a microscope. Depending on which part of the body is affected, a local or general anaesthetic is given.