الفهرس 
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Abstract
The parathyroid glands are endodermal in origin and develop from the dorsal wing of the third and fourth pharyngeal pouches. They produce parathyroid hormone (PTH) which regulates the circulating level of calcium through intestinal and renal absorption and bone remodeling. There are typically four parathyroid glands; however, supernumerary glands and less than four glands have been reported. The superior parathyroid glands originate from the fourth pharyngeal pouch. As they lose their attachment with the pharyngeal wall, they attach to the posterior surface of the inferiorly migrating thyroid. While the dorsal wing of the third pharyngeal pouch gives rise to the inferior parathyroid glands, the ventral wing gives rise to the thymus during the fifth week of gestation. A rare ectopic location that could be a source of pitfall during parathyroid surgery for hyperparathyroidism is the intrathyroid location of the parathyroid glands.
Primary hyperparathyroidism may result from adenoma (single gland disease, accounting for 80–85% of cases; adenomas involving two or more glands are definitely less common), hyperplasia (multiglandular disease, accounting for 10–15% of cases), or carcinoma (less than 1% of cases, which typically involves a single gland).
There are several clinical manifestations of primary hyperparathyroidism (pHPT) which could present as asymptomatic form, as symptomatic form, or (rarely) as an acute form causing a hypercalcemic crisis. Moreover, recently a new clinical entity is emerging that is normocalcemic primary hyperparathyroidism (NCpHPT) probably representing the first stage of the disease. Furthermore, pHPT is a rare presentation in pregnancy. The clinical manifestations of pHPT are the result of the effect of hypercalcemia to human body tissues. Also, hypovitaminosis D has the potential to affect clinical presentation of pHPT with mostly symptomatic forms prevailing in severe vitamin D deficient geographical areas.
Classical symptoms and signs involve the two main target organs, i.e., bone and kidney, as well as cardiovascular and metabolic alterations, neuropsychiatric symptoms and cognitive change, neuromuscular and gastrointestinal manifestations. Moreover, hypercalcemic crisis with nephrogenic diabetes insipidus, dehydration, acute kidney failure, somnolence and coma could be ascribed to severe hypercalcemia. Modern day presentation of the disease, largely asymptomatic, it is characterized by mild hypercalcemia and slightly elevated or inappropriately normal serum PTH levels, due to the early detection of pHPT related to the incidental finding of hypercalcemia on routine biochemical screening or during the diagnostic workup of patients with low bone mass and/or nephrolithiasis. The diagnosis of pHPT should exclude other disorders characterized by secondary or compensatory increase of PTH with normal or increased calcium concentrations:
• Vitamin D deficiency
• Chronic kidney disease
• Drugs
• Hypercalciuria
• Hypocalciuric hypercalcemia
• Malabsorption syndromes.
The parathyroid glands can be investigated with different imaging modalities: ultrasonography, scintigraphy, computed tomography (CT) scan and magnetic resonance (MR).
Otherwise in management of Hyperparathyroidism we can conclude that:
• Symptomatic pHPT always necessitates surgery unless there are objective or subjective contraindications.
• Asymptomatic pHPT, if the latest guidelines are adopted, must be operated, otherwise they need to be monitored annually.
• The number of asymptomatic pHPT is definitely overestimated in that, thanks to new investigative methods and a deeper knowledge of the action of the parathyroid hormone, the symptoms are recognized sooner.
• Parathyroidectomy in expert hands is a safe and efficient intervention, and it is more economical when compared to the cost of medical treatment and the follow-up.
Once the decision to operate is made, the second step is to decide what the best approach for the patient is, in order to obtain excellent results. The choice will be between a standard bilateral neck exploration (BNE) and a more focused minimally invasive PTx. Endocrine surgeons should be skilled in all of the targeted approaches so that the operative strategy can be individualized. Patients who do not have concordant dual imaging (scintigraphy and ultrasound) or have negative imaging, are at higher risk of persistent HPT due to MGD: four-gland exploration remains an excellent first-line option in these situations.