Tests for carcinoid tumour of the lung

A chest X-ray looks for anything that is abnormal. Chest X-rays don’t give a very detailed picture. If you have a clear X-ray but your doctor still thinks that you may have a carcinoid you will probably need either a CT scan or an MRI scan as well.

CT scanners take X-ray pictures from different angles to form a detailed picture of the inside of your body. The doctor uses the scan to look at the tumour, and see whether it has spread anywhere else in the body. There is further information about CT scans in our cancer tests section.

An MRI scan uses magnetism rather than X-rays to build up a picture. MRI scans are especially good at showing up soft tissue. For this scan you need to change into a special gown and remove jewellery and any other metal. During the scan you need to lie very still. You may find it very noisy and will have earplugs or headphones to help block out the noise. There is more information about MRI scans in our section about cancer tests.

A PET scanner uses a mildly radioactive glucose liquid injected into a vein. The liquid gets taken up by tumour cells so the scan may show if there are any tumours. There is detailed information about PET scans in our section about cancer tests.

An octreoscan is a type of radioactive scan. This test is also called a somatostatin receptor scintography test. Octreotide is a substance that carcinoid cells may take up (absorb). Doctors attach a radioactive substance to the octreotide, which then shows up on the scan. You have the octreotide as an injection and then have a scan using a special type of scanner. You usually have three scans over three days, starting on the day of the injection. The scans show up areas where radioactivity has collected. This may show where the carcinoid tumour is in the body and if it has spread anywhere else.

A bronchoscopy test examines the inside of your airways through a narrow flexible tube that your doctor passes down your throat. Your doctor looks down the tube at the lining of your airway and may take samples of tissue (biopsies). They may also use a brush to take samples of the tumour cells. You have this test under local or general anaesthetic. If you have a general anaesthetic, you may need to stay in hospital overnight.

If the tumour is in a part of the lung that is hard to reach, your surgeon may do an operation (thoracotomy) to take a sample of the tumour. Or they may use a CT scan to guide a needle into the tumour.

If your biopsy doesn’t find a carcinoid but your doctor thinks you are likely to have one, you may have an endobronchial ultrasound. You generally have medicines to make you relax, rather than a general anaesthetic. So you can usually have this test as an outpatient.

After your sedation has worked, the doctor passes a flexible tube called an endoscope into your airway, in the same way as having a bronchoscopy. The endoscope creates ultrasound pictures of the area around the airways. If the doctor sees a carcinoid tumour, they can take biopsies.

Carcinoids can release high amounts of serotonin. The body breaks down serotonin to a substance called 5HIAA. We get rid of 5HIAA in our urine, so a raised amount in the urine can be a sign of carcinoid. Your doctor or nurse will ask you to collect all your urine over 24 hours to measure the amount of 5HIAA.

Some carcinoids make hormones. These cause the symptoms of carcinoid syndrome. Blood tests can help find these substances. The tests include one to measure the amount of serotonin in the blood and one to measure the amount of a protein called chromogranin A (CgA). When carcinoid tumour cells release this protein, the amount in the blood goes up.

If you have carcinoid syndrome you have a higher risk of heart disease. You will have an echocardiogram at diagnosis and continue to have regular check ups. If you have any changes in your heart, you will see a doctor who specialises in heart problems. You may need to take tablets to help. Some people may need to have surgery to the heart valves.