Thyroid Cancer Symptoms and Test
Thyroid cancer is a condition characterized by abnormal growth of the cells in the thyroid gland. When the cells grow in an abnormal structure a tumor or nodule eventually forms. Thyroid tumors are most often benign or noncancerous; only about 10% are malignant or cancerous.
About the Thyroid Gland
The thyroid gland, composed of two connected lobes, is part of the endocrine system. It contains two types of cells, follicular and C cells. Follicular cells function to produce thyroid hormone. C cells produce the hormone calcitonin, needed for calcium metabolism.
Types of Thyroid Cancer and Symptoms
Papillary thyroid cancer, the most common type of thyroid cancer, is slow growing and involves the follicular cells. The cancer cells mimic the structure of healthy thyroid cells.
Follicular thyroid cancer is similar to papillary cancer but less common. It also involves the follicular cells and is slow growing. The difference is that follicular cancer cells do not look like healthy cells.
Medullary thyroid cancer involves the C cells. This variety sometimes results from a genetic anomaly. This variety accounts for about 5% of diagnosed thyroid cancer.
Anaplastic thyroid cancer is rare and accounts for about 2% of diagnosed thyroid cancer. It is fast growing, develops from a noncancerous thyroid tumor and is difficult to treat.
Symptoms
- During the early stages of thyroid cancer there may be no symptoms.
- The most common symptom of thyroid cancer is the presence of a lump in the neck. One side of the neck may have a different shape or size than the other, causing an asymmetrical appearance.
- Difficulty swallowing
- Difficulty breathing
- Hoarse voice
- Swollen lymph nodes in the neck
- Neck pain
- Throat pain
Tests for Thyroid Cancer
- A physical examination of the neck and surrounding structures will reveal the presence of swelling, abnormal tissue growth or nodules.
- Blood tests revel abnormal hormone levels that can be caused by thyroid cancer. Irregular thyroid stimulating hormone, calcitonin and calcium levels are indicators, as well as the presence of altered RET genes.
- Untrasound images are used to collect data on location, size and structure of tumors or nodules.
- A radionuclide scan uses nuclear medicine to illuminate the thyroid and provide a better image. This test also provides information on the condition of the tumors. Tumors that readily absorb the radioactive material are less likely to be cancerous.
- A biopsy involves collecting a tissue sample from the affected area. The sample is then examined under a microscope. A fine-needle aspiration biopsy involves inserting a needle into the nodule and collecting cells on a syringe. A surgical biopsy involves manually removing small sections of tissue under local or general anesthetic.