Parathyroid cancer is a rare malignancy originating in one of the small parathyroid glands located in the neck. This condition leads to an overproduction of parathyroid hormone, causing abnormally high calcium levels in the blood. Understanding its nature, detection, and management is important.
Understanding Parathyroid Glands and Their Role
Most individuals have four tiny parathyroid glands, located behind the thyroid gland in the lower neck. These pea-sized glands are distinct from the thyroid, despite their close proximity. They are part of the endocrine system, regulating various bodily functions.
The primary function of the parathyroid glands is to produce parathyroid hormone (PTH). This hormone plays a central role in maintaining calcium and phosphorus balance within the blood and bones. PTH helps release calcium from bones into the bloodstream, aids the kidneys in reabsorbing calcium, and assists the intestines in absorbing calcium from food.
Characteristics of Parathyroid Cancer
Parathyroid cancer is a rare disease. It accounts for less than 0.5% of cases of hyperparathyroidism, a condition characterized by overactive parathyroid glands. This malignancy develops when one of the parathyroid glands forms a cancerous tumor.
The most common manifestation of parathyroid cancer is the excessive production of PTH, leading to elevated calcium levels in the blood, a condition known as hypercalcemia. Symptoms associated with hypercalcemia can include fatigue, increased thirst and frequent urination, nausea, constipation, bone pain, and impaired mental clarity. While slow-growing, parathyroid cancer can be locally invasive, potentially affecting surrounding tissues like the thyroid, muscles, or nerves in the neck.
Diagnosing Parathyroid Cancer
Diagnosing parathyroid cancer begins with blood tests to measure calcium and parathyroid hormone (PTH) levels. Very high levels of both calcium and PTH suggest parathyroid cancer. These blood markers provide initial indicators of an overactive parathyroid gland.
Imaging techniques are used to locate the abnormal gland and assess the extent of the disease. Common imaging methods include ultrasound, CT scans, MRI, and Sestamibi scans. A Sestamibi scan involves injecting a radioactive substance that is absorbed by overactive parathyroid glands, making them visible on special cameras.
Despite these tests, a definitive diagnosis of parathyroid cancer is challenging to make before surgery. This is because cancerous parathyroid cells can appear similar to those of benign parathyroid adenomas under a microscope. Therefore, the final diagnosis relies on the pathological examination of the tissue after surgical removal of the affected gland.
Treatment Approaches for Parathyroid Cancer
The primary treatment for parathyroid cancer is surgical removal of the cancerous gland. This procedure, known as parathyroidectomy, aims for complete resection of the tumor and any involved surrounding tissues. This may include removing nearby lymph nodes, part of the thyroid gland on the same side, and any muscles or nerves that the cancer has invaded.
Complete surgical removal is important, as it is the only potentially curative treatment. If the cancer cannot be fully removed or if it recurs or spreads, other treatments may be considered. These can include radiation therapy, which uses high-energy X-rays to target cancer cells, or chemotherapy, which uses medications to destroy cancer cells. Targeted therapies may also be used to manage persistent high calcium levels.
Prognosis and Ongoing Care
The outlook is influenced by several factors, including the completeness of initial surgical removal and whether the cancer has spread. While surgical cure is possible, recurrence is a consideration. Early detection of recurrence through ongoing monitoring is important for effective management.
Regular follow-up appointments involve blood tests to monitor calcium and PTH levels. Imaging studies are also performed periodically to check for any signs of the cancer returning. If calcium or PTH levels begin to rise, it can indicate a recurrence, prompting further investigation to locate and address any new tumor growth.