Ossification is the process of bone formation in which calcium is brought by blood vessels and deposited on the ossifying tissue. When the same mineral (calcium) happens to build up on soft tissues and causes it to harden, the process is known as calcification. Calcification on any soft tissue, including the thyroid, can pose numerous problems. For example, calciphylaxis is vascular calcification seen in some patients with primary hyperparathyroidism, hypercalcemia.
Hyperparathyroidism is the over activity of the parathyroid glands. Parathyroid glands are small endocrine glands which produce parathyroid hormone (PTH) and are located behind the thyroid gland. Most of us have four parathyroid glands, but in certain individuals there are six or even eight. The function of the parathyroid glands is to maintain calcium levels in the blood within a narrow range so that the muscular and nervous systems can function to optimal capacity. Hyperactivity of the parathyroid is usually caused due to adenoma (benign epithelial growth), hyperplasia (abnormal increase in number of cells), and in rare cases, carcinoma.
The thyroid itself is also prone to various thyroid conditions, including the formation of nodules around it. The chance of malignancy in a calcified thyroid nodule is much higher than in an average thyroid nodule. Approximately 60% of patients with calcification on the thyroid are diagnosed with cancer of the thyroid epithelial tissue, and the rest are found to have multi-nodular goiters. The risk of malignancy is higher in solitary nodules.
Diagnosing thyroid problems is a challenge in itself due to the wide range of symptoms that are associated with improper thyroid health. Calcification on the thyroid poses a bigger challenge to radiologists, often leading to a wrong diagnosis. Peripheral calcification on the thyroid nodule is often overshadowed with minimal visualization of the internal structure.
Ultrasound is the best mode for detection of thyroid nodules, but there is a disagreement among physicians regarding imaging techniques for diagnosing. While some of them utilize ultrasound, others recommend radionuclide imaging or nuclear scintigraphy for characterization of a thyroid nodule. However, there is agreement that average nodules are better differentiated from carcinomas using uptake of iodine-123 studies. Fine needle aspiration cytology (FNAC), for investigating lumps and masses just under the skin, is another safe and inexpensive diagnostic tool available for establishing the nature of the nodule. However, the findings of FNAC may be misleading at times.
Although hormonal suppression therapy may be recommended, it is not the preferred choice of treatment, as its effectiveness is open to doubt. In most cases, physicians advise surgical resection to be on the safer side.