Thyroid Cancer Diagnosis

Diagnosing Thyroid Cancer

Most thyroid cancers are diagnosed from the results of a biopsy. Doctors often perform a fine needle aspiration biopsy to remove cells from several areas of a nodule. Cells are removed from multiple areas of the nodules that are at least a half-inch in diameter. Also, doctors may need to biopsy a nodule again if not enough cells are collected the first time.

It is not possible to confirm the presence of thyroid cancer in a nodule using a blood test. However, there are a few blood tests available that may be used to help diagnose thyroid cancer. Levels of the thyroid-stimulating hormone (TSH) in blood may be used as an indicator of the thyroid glands activity and function.

If there is a possibility of medullary thyroid carcinoma (MTC), testing the levels of calcitonin in the blood may help verify the presence of cancer. High levels of a protein found in the blood called carcinoembryonic antigen (CEA) may also alert doctors to the presence of MTC. The results of a blood test may also help your doctor decide which imaging tests are best.

Testing for Thyroid Cancer

Most imaging tests provide more information about a potentially cancerous area. Common tests your doctor may recommend include:

• Ultrasound - Images of the nodules in the thyroid can be created using the reflection of high-frequency sound waves. This technique is also sometimes referred to as sonography and is a non-invasive procedure that may be recommend to individuals who have discovered a lump near their thyroid. This test can help doctors determine the size of nodules and see how many are present. Some doctors also use this test to guide a biopsy needle when nodules are small.

• Computed tomography (CT) - This is a method of taking cross-sectional x-rays of the body in order to determine the location, size and spread of thyroid cancer. There are some cases where a CT scan may also provide precision guidance for a biopsy needle. Patients lay on a special CT table while a doctor scans areas of the body for metastases.

• Magnetic resonance imaging (MRI) - These scans provide additional, detailed images of soft tissues by using radio waves and strong magnets instead of x-rays.

• Nuclear medicine scans - A small amount of radiation is injected into the patient's arm. Pictures are taken with a special gamma camera and the images are used to detect cells in the body that are not behaving normally. The images produced by these tests are not very detailed.

It is common for doctors to order these tests throughout your treatment to gauge whether therapies are working. Each situation is unique and your doctor may recommend certain tests or exams based on your specific condition and needs.

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