Parathyroid Gland

Background: Primary hyperparathyroidism (PHPT) is a common clinical endocrine disorder. It is the most common
cause of hypercalcemia in the outpatient setting. This review presents a brief summary of the new trends of presentation,
diagnosis and management PHPT.
Data Sources: PubMed (National Library of Medicine) articles, and Memorial Library archives of the University of
Wisconsin System.
Conclusions: PHPT occurs at any age, but it is most commonly seen in people over the age of 50 years and
postmenopausal women. The current presentation of PHPT shifts from the classical symptomatic form to the
asymptomatic form; however, parathyroidectomy is still the treatment of choice for both symptomatic and asymptomatic
forms. In the past, bilateral neck exploration and intraoperative identification of all 4 parathyroid glands was the
standard of treatment, nevertheless, nowadays, with the introduction of the preoperative and intraoperative localization
techniques, the minimally invasive parathyroidectomy has evolved.

BACKGROUND: Hyperparathyroid crisis is an uncommon, potentially lethal condition for which emergent parathyroidectomy has been advocated. STUDY DESIGN: The manifestations of hyperparathyroid crisis and outcomes of bisphosphonate-based therapy and delayed parathyroidectomy were determined and compared with cases from a review of the literature. Laboratory indices and gland weights were compared with those from patients with primary hyperparathyroidism without crisis.

Primary hyperparathyroidism (PHPT) is both underdiagnosed and undertreated. The most common causes for delayed diagnosis include failure to note hypercalcemia, poor workup for hypercalcemia, or not contemplating a diagnosis of HPT. The majority (99.8%) of patients who have an elevated serum calcium level have a problem in one or more of their parathyroid glands. Any serum calcium concentration above 10.2 mg/dl should alert the health care provider of the possibility of PHPT. This paper is intended to contribute to the education of health care providers and patients about the importance of early diagnosis and about the more subtle complications of PHTP to create a sense of urgency for management and appropriate referral of the patient to a specialist. The only definitive and curative treatment of PHPT is an operation that can prevent all the deleterious consequences of the disease.

Amaç: Sekonder hiperparatiroidizm (sHPT), kronik
böbrek yetmezliği (KBY) olan hastalarda morbidite ve
mortaliteye sebep olmaktadır. Medikal tedaviye cevap
vermeyen olgularda paratiroidektomi gerekmektedir.
Bu çalışmamızda KBY’li hastalarda paratiroidektomi
endikasyonlarımızı değerlendirmeyi amaçladık.
Gereç ve yöntem: Bu çalışmada Kasım 2006 ile Kasım
2010 tarihleri arasında Şişli Etfal Eğitim ve Araştırma
Hastanesi 2.Genel Cerrahi Kliniği’nde KBY sonucu gelişen
sHPT nedeniyle subtotal paratiroidektomi ve servikal
timektomi uygulanan 34 hasta retrospektif olarak
değerlendirildi.
Bulgular: Hastalardan 18’i kadın 16’sı erkek olup, yaş
ortalaması 53,6 (23-75) idi. Hastalarda en sık rastlanan
semptom kas güçsüzlüğü ve kemik ağrıları idi. Kas güçsüzlüğü
25 hastada (%74), kemik ağrıları ise 19 hastada
(%55) mevcut idi. Operasyon öncesi yapılan radyolojik
incelemede çekilen el grafisinde 15 hastada (%44) subperiostal
rezorbsiyon saptandı. Altı hastada (%17,6) ise
spontan kemik kırığı tespit edilirken bir hastada kalsiflaksi
saptandı.
Sonuç: Böbrek yetmezliğine bağlı sekonder hiperparatiroidi
kalsiyum ve vitamin D tedavisine cevap vermesine
rağmen uzun dönemde kas iskelet sisteminde
komplikasyonlar gelişmekte ve cerrahi tedavi önem kazanmaktadır.
Subtotal paratiroidektomi uygulanan vakalarda
klinik olarak belirgin iyileşme, laboratuar
bulgularında düzelme görülmektedir. Medikal tedaviye
dirençli sekonder hiperparatiroidili hastalarda cerrahi
tedavi en uygun yöntemdir.

Background. Heterozygous inactivating mutations of the calcium-sensing receptor (CaSR) are the most common cause of familial hypocalciuric hypocalcemia (FHH). Patients typically have mild, asymptomatic hypercalcemia with normal to modestly elevated parathyroid hormone (PTH) level, 24 hour urine calcium < 200 mg, and a calcium/creatinine clearance ratio (CCCR) < 0.01. We present a case of familial hypercalcemia with CaSR gene mutation and phenotypic features of primary hyperparathyroidism (PHPT).

Case. A 27 year old female was referred for evaluation of persistent hypercalcemia. The patient was incidentally discovered to be hypercalcemic approximately six years before referral. Nine serum calcium measurements ranged from 10.8-11.6 mg/dL (8.5-10.4) from initial discovery of hypercalcemia through end of metabolic evaluation. PTH level on diagnosis of hypercalcemia was 27 pg/mL (12-88), and three additional measurements ranged from 37-50 pg/mL. Three measurements of 25-hydroxyvitamin D level ranged from 22-31 ng/mL. Initial 24 hour urine calcium was 132 mg, though urine creatinine was not measured to allow calculation of CCCR. The patient’s father (deceased), daughter, and a niece had been diagnosed with hypercalcemia, prompting sequencing of the CaSR gene that revealed a heterozygous sequence variant (c.2657G>C) in exon seven predicting a R886P substitution in the receptor. Another 24 hour urine collection yielded a calcium of 272 mg, and CCCR was equivocal (0.016). A DXA scan obtained before referral and following traumatic right hand fracture was notable for marginal Z-scores of the distal third of the radius (-1.7), left femoral neck (-1.9), and left total hip (-1.8). Three serum phosphate levels were low or marginal (2.3-2.6 mg/dL, 2.5-4.5). Approximately 15 months after referral, the patient experienced right nephrolithiasis. No parathyroid adenomas were identified on sestamibi parathyroid scintigraphy. Unfortunately, the patient was lost to follow up.

Conclusion. CaSR mutation positive hypercalcemia may present with biochemical and clinical manifestations that are atypical for FHH. For example, the F881L mutation has been linked to hypercalciuria and nephrolithiasis that benefitted from parathyroidectomy. The R886P mutation found in our patient maps near F881L, and the proband in the initial R886P kindred presented with an elevated PTH level, 24 hour urine calcium > 200 mg, and CCCR > 0.02. However, no PHPT phenotype was described in this kindred. PHPT may also co-occur with CaSR mutations; in a German series of 139 PHPT patients, four had co-existing features of FHH and confirmatory CaSR mutations. Case reports of concurrent FHH and PHPT have also been published, though in our patient parathyroid imaging failed to clearly identify an adenoma. This case demonstrates that familial CaSR mutation positive hypercalcemia may not have the benign course typical of FHH.

Background—Parathyroid cryopreservation is often utilized for patients having parathyroidectomy. This allows for future autotransplantation if a patient becomes permanently hypocalcemic after surgery. However, the practice of cryopreservation is costly and time consuming, while the success rate of delayed autotransplantation is highly variable. We sought to determine the rate and outcomes of parathyroid cryopreservation and delayed autotransplantation at our institution to further evaluate its utility.

The concept of surgical invasiveness cannot be limited to the length or to the site of the skin incision. It must be extended to all structures dissected during the procedure. Therefore, MIT or MIP should properly be defined as operations through a short and discrete incision that permits direct access to the thyroid or parathyroid gland, resulting in a focused dissection. Parathyroid glands are particularly suitable for minimally invasive surgery as most parathyroid tumors are small and benign. MIP are performed through a limited or discrete incision when compared to classic open transverse cervical incision and are targeted on one specific parathyroid gland. The concept of these limited explorations is based on the fact that 85% of patients will have single-gland disease. MIP must be proposed only for patients with sporadic hyperparathyroidism in whom a single adenoma has been clearly localized by preoperative imaging studies. The minimal access approaches to the thyroid gland may be broadly classified into three groups: the mini-open lateral approach via a small incision, minimally invasive video-assisted thyroidectomy via the midline and various endoscopic techniques. Endoscopic extracervical approaches have the main advantage of leaving no scar in the neck but cannot reasonably be described as minimally invasive as they require more dissection than conventional open surgery. Initially the indications for MIT were a solitary thyroid nodule of less than 3 cm in diameter in an otherwise normal gland. Today, MIT are also proposed in patients with small nodular goiters, Graves's diseases and low risk papillary thyroid cancers. Some concern remains about the radicality of MIT in this latter group but preliminary results are comparable to those of conventional surgery both in terms of I–131 uptake and serum thyroglobuline levels. Demonstrating the advantages of MIT and MIP over conventional surgery is not easy. Main complications, such as nerve injury, hypoparathyroidism, or hemorrhage, are the same as in conventional surgery. Several studies comparing conventional surgery with minimally invasive techniques using a cervical access have shown a diminution of postoperative pain, and better cosmetic results with minimally invasive techniques. MIP and MIT seem overall to be an advance but only randomized studies will demonstrate the real benefit.