Diagnosis of hyperparathyroidism

Typically, the diagnosis of hyperparathyroidism is an incidental finding. As part of a thorough assessment, blood work is often done and the calcium blood level is found to be high (high serum calcium). Whenever high levels of calcium in blood are found, assessment and determination of the source is indicated. The workup should be very thorough to include other causes of high serum calcium levels. The workup should also include assessment of vitamin D levels. The most definitive test would be the determination of the intact parathyroid hormone levels. The parathyroid glands are located right behind the thyroid and are extremely small in normal patients. The actual size of the parathyroid gland is approximately 20 mg, which is the size of a grain of rice. The parathyroids are the smallest glands in the neck and probably the smallest glands in the human body. Once an elevation of parathyroid hormone level is detected, further evaluation by a parathyroid specialist is indicated. Thyroid surgeons are often also parathyroid experts and often deal with both diseases of the thyroid and the parathyroid. Endocrinologists are specialists that deal with glands in the body. Therefore they are parathyroid care specialists. Endocrinologists are often involved in making the definitive diagnosis of primary hyperparathyroidism. The testing will often include a nuclear medicine scan in addition to assessment of calcium levels to confirm high serum calcium. The purpose of a nuclear scan is to identify which of the four parathyroid glands is involved. There are four parathyroid glands located right behind the thyroid gland and in most cases only one of the four glands is abnormal. In over 90% of the patients, three of their four glands will be normal but one will be enlarged and present A negative scan means that the abnormal gland or abnormal glands did not take up the sestamibi itself as a small tumor that is causing the high calcium levels. The nuclear medicine scan called the sestamibi scan is used to identify which of the glands is abnormal. A positive scan shows that the gland is overactive. The scan may be positive for one out of four or may be positive for all four glands. When all four glands are considered positive, the implication is that all four glands are abnormally enlarged. This condition is called parathyroid hyperplasia. In this situation, the disease involves all four parathyroid glands and removal of parts of all of these glands would be essential for complete cure. Treatment of hyperplasia is far more complicated than treatment of a parathyroid adenoma and only parathyroid surgical specialists should deal with treatment of parathyroid hyperplasia. A negative scan is also a relatively common finding. It does not mean that the patient does not have hyperparathyroidism. Approximately 15% of patient with primary hyperparathyroidism have negative scans. In cases of a negative scan, the surgeon explores all the four parathyroid glands and identifies the abnormal gland with direct visualization.