Hyperparathyroidism

Introduction The parathyroid gland secretes excessive parathyroid hormone (PTH) and causes abnormal calcium and phosphorus metabolism. Referred to as a paralysis. Mainly manifested as bone changes, urinary stones, high blood calcium and low blood phosphorus. Can be divided into four types: primary, secondary, triple and false.

Cause

The cause of primary hyperparathyroidism is unknown. It has been reported that the incidence of benign or malignant parathyroid glands and thyroid tumors after cervical radiation therapy is 11 to 25%. In some families, fathers and daughters, mothers and children, brothers and sisters suffer from this disease. Therefore, the relationship between the occurrence of this disease and radiation exposure and heredity needs further study. Secondary hypothyroidism caused by various causes of secondary hyperparathyroidism is caused by long-term stimulation of parathyroid glands, such as chronic renal failure, vitamin D deficiency, intestinal D, malabsorption and malformation caused by intestinal, liver and kidney diseases. In pregnant and lactating women, when calcium requirements are increased and they are not supplemented accordingly, hypocalcemia is also present. In all the above cases, parathyroid hyperplasia can be hypertrophied and excessive PTH is secreted. On the basis of secondary hyperparathyroidism, the parathyroid glands are sustained and strongly stimulated. One or more of the hyperplastic glands may develop into autonomous adenomas, which are found in chronic renal failure.

an examination

Related inspection

Anti-thyroceptin receptor antibody (TRAb) Parathyroid hormone (PTH) test thyroid B-mode ultrasonography serum total thyroxine (TT4) free thyroxine index (FT4I)

Blood PTH concentration is a direct and sensitive indicator for the diagnosis of this disease. At present, there are several kinds of radioimmunoassay methods for measuring the amino terminal, middle segment and carboxyl terminal of PTH. The use of this index to diagnose the compliance rate of hyperparathyroidism and surgery is about 90%. . And the degree of elevated blood PTH is parallel with the blood calcium concentration, tumor size and severity of the disease. However, in the secondary hyperparathyroidism, PTH can also be elevated, and blood PTH combined with blood calcium, urinary calcium, X-ray examination and clinical manifestations are analyzed to help the differential diagnosis of the two. Urinary cyclic adenosine monophosphate (cAMP) can be elevated. Bone density is generally reduced. X-ray characteristic bone changes are more common in the skull, hard plates, hands and pelvis. Abdominal plain films may have urinary stones and renal calcification.

Most lesions of the parathyroid glands are located in the neck. If the first neck exploration procedure fails, consider whether there are other causes of hypercalcemia. If it is considered that the diagnosis of hyperparathyroidism is still met, it is best to perform a localization examination before reoperation. The non-invasive examination includes: ultrasonic tomography, 99mTc-201Tl double isotope subtraction scan, and the coincidence rate between the two and surgery is 70% and 90% respectively. Left and right, can detect lesions with a diameter of more than 1cm, CT scan helps to exclude mediastinal lesions, but it is expensive. Selective thyroid venous blood test PTH is a traumatic examination, but the specificity is strong, the diagnostic coincidence rate is 70-90%. The positive rate of thyroid angiography is not high, and it is dangerous. It should be used with caution.

Differential diagnosis

Pseudohypoparathyroidism: pseudo-hypoparathyroidism is a hereditary disease with symptoms and signs of hypoparathyroidism. Albright was first reported in 1942, so it is also called Albright hereditary bone dystrophy. This disease is mainly caused by target organ (bone and kidney) desensitization to parathyroid hormone, hyperparathyroidism, and increased parathyroid hormone in the blood. The clinical manifestations are hypoparathyroidism; typical cases also have unique bone and developmental defects.

Secondary hyperparathyroidism: secondary hyperparathyroidism (SHPT, referred to as secondary hyperparathyroidism), refers to chronic renal insufficiency, intestinal malabsorption syndrome, Fanconi synthesis In the case of renal tubular acidosis, vitamin D deficiency or resistance, and pregnancy, breastfeeding, etc., the parathyroid glands are stimulated by hypocalcemia, hypomagnesemia or hyperphosphatemia for a long time to secrete excess PTH to improve blood calcium and blood. Magnesium and a chronic compensatory clinical syndrome that lowers blood phosphorus. With varying degrees of parathyroid hyperplasia, but not caused by the disease of the parathyroid gland itself.

Blood PTH concentration is a direct and sensitive indicator for the diagnosis of this disease. At present, there are several kinds of radioimmunoassay methods for measuring the amino terminal, middle segment and carboxyl terminal of PTH. The use of this index to diagnose the compliance rate of hyperparathyroidism and surgery is about 90%. . And the degree of elevated blood PTH is parallel with the blood calcium concentration, tumor size and severity of the disease. However, in the secondary hyperparathyroidism, PTH can also be elevated, and blood PTH combined with blood calcium, urinary calcium, X-ray examination and clinical manifestations are analyzed to help the differential diagnosis of the two. Urinary cyclic adenosine monophosphate (cAMP) can be elevated. Bone density is generally reduced. X-ray characteristic bone changes are more common in the skull, hard plates, hands and pelvis. Abdominal plain films may have urinary stones and renal calcification.

Most lesions of the parathyroid glands are located in the neck. If the first neck exploration procedure fails, consider whether there are other causes of hypercalcemia. If it is considered that the diagnosis of hyperparathyroidism is still met, it is best to perform a localization examination before reoperation. The non-invasive examination includes: ultrasonic tomography, 99mTc-201Tl double isotope subtraction scan, and the coincidence rate between the two and surgery is 70% and 90% respectively. Left and right, can detect lesions with a diameter of more than 1cm, CT scan helps to exclude mediastinal lesions, but it is expensive. Selective thyroid venous blood test PTH is a traumatic examination, but the specificity is strong, the diagnostic coincidence rate is 70-90%. The positive rate of thyroid angiography is not high, and it is dangerous. It should be used with caution.

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