How are lung carcinoid tumors diagnosed?
Your doctor will ask you about your medical history and any symptoms that you have. He or she will listen to your lungs and check your breathing. If your doctor suspects that there is a problem with your lungs, he or she will order more tests.
Imaging tests include chest X-rays and computed tomography scans.
Chest X-rays might indicate the presence of a lung carcinoid tumor, except in cases where the tumor is very small or is hidden by other organs in the chest.
Computed tomography scan (CT scan): If chest X-rays are not clear, a CT scan might be performed. A CT scan yields images that provide a cross sectional view of the lungs and chest. Unlike regular X-rays, CT scans can detect very small lung tumors and pinpoint their exact location. They are also useful in seeing if the tumor has spread to the liver or other organs.
Depending on the test results, your doctor may order other tests to find out if the tumor is a carcinoid or some other form of lung cancer.
Blood and urine tests: Abnormal levels of hormones or other substances linked with carcinoid tumors might be present in the blood or urine. Blood tests to measure the levels of serotonin or chromogranin-A might indicate the presence of a typical carcinoid. Urine tests can measure the level of 5-HIAA, a metabolite of serotonin. These tests are most helpful in the small percentage of people with lung carcinoid tumors who present with the carcinoid syndrome. In most others these tests will be normal.
Biopsy: A biopsy is a procedure in which a small sample of the tumor or growth is removed so that the cells can be examined under a microscope. There are two major types of biopsies:
- Nonsurgical biopsies are done in a hospital or clinic, but they do not require a surgical incision. Although you will have to be sedated before the procedure, recovery times are short. You will probably be able to leave the hospital a few hours after the biopsy is done. The most common type of nonsurgical biopsy for carcinoid tumors is called a bronchoscopy, where a thin, flexible camera is inserted into the breathing passages allowing a biopsy to be performed under direct vision.
- Surgical biopsies are performed under anesthesia and require a surgical incision to be made in the chest. It requires hospitalization and the recovery time is longer than for nonsurgical biopsies.