Primary hyperparathyroidism can be sporadic or part of a genetic syndrome, such as MEN1 or HPT-JT. Diagnosis of hereditary HPT requires a thorough history and physical. Parathyroidectomy is curative with greater than 95% success. However, some patients have persistent or recurrent disease requiring reoperation. Reoperative parathyroidectomy is technically challenging, and localizing the pathologic gland can difficult. Patients needing reoperation should undergo evaluation by a high-volume surgeon. Care should be taken to obtain all of the preoperative workup and operative note from the initial surgery. Radioguided parathyroidectomy can be safely and effectively performed in patients with hereditary HPT or undergoing reoperative surgery.

BACKGROUND: Currently, parathyroidectomy is the standard treatment for Primary Hyperparathyroidism (PHPT). Surgical treatment is often effective, although not free of complications and relapses. Minimally invasive techniques, such as Microwave Ablation (MWA) and Radiofrequency Ablation (RFA), are an alternative to surgery in selected patients. We have, herein, reported on the successful use of RFA in a patient with post-surgical persistent hyperparathyroidism.
METHODS: A 54-year-old woman was referred to our Center for mild hypercalcemia with exams revealing Primary Hyperparathyroidism (PHPT). Neck ultrasound and Technetium- 99 Methoxy-isobutyl-isonitrile (99mTc-MIBI) scintigraphy scanning revealed a suspicious right parathyroid hyperplasia/adenoma. She underwent parathyroidectomy and histological examination showed a parathyroid nodular hyperplasia. During the follow-up, she suffered from persistent hyperparathyroidism due to the treatment of left parathyroid hypoplasia with RFA. Blood tests after the procedure showed the remission of the disease 7 months post-treatment.
CONCLUSIONS: A minimally invasive technique for PHPT may represent a valid alternative to surgery, especially in patients with an elevated surgery-related risk. More studies are necessary to investigate the benefit of RFA as a first-line treatment in PHPT.

Reoperative parathyroid surgery is challenging even for experienced surgeons. Cure rates are lower than primary surgery. Good anatomical and embryological knowledge is important. Preoperatively, a comprehensive surgical strategy should be planned. Pre-operative imaging modalities should be used extensively to find the overlooked gland to have a possibility to perform focused parathyroid surgery to avoid possible complications. One of the important developments is the new ancillary methods to find overlooked parathyroid glands. Orthotopic and possible ectopic locations should be known well by the surgeon to increase the surgical success rate. Reoperative parathyroid surgery needs a distinctive approach compared to primary parathyroid surgery. Basic principles include the selection of the incision and route for entering the thyroid region, use of ancillary methods, and intraoperative nerve monitoring and also require a meticulous dissection. Obtaining a surgical cure is difficult and high surgical caution is needed. Post-operative complication rates are higher compared to primary parathyroid surgery. Other treatment methods and medical treatment options may be evaluated in a patient who cannot undergo surgery.

Chronic kidney disease-mineral and bone disorder is one of the complications associated with chronic kidney disease. About 10-50% of patients following kidney transplantation have persistent hyperparathyroidism. Hypercalcaemic hyperparathyroidism has a negative impact on the kidney transplant outcome; therefore, it requires treatment. The data regarding the treatment of persistent hyperparathyroidism provided in scientific publications are divergent and contradictory. Therefore, the aim of our systematic review was to evaluate the efficacy of persistent hyperparathyroidism treatment in patients following kidney transplantation. The Cochrane, PubMed, and Scopus databases were browsed independently by two authors. The search strategy included controlled vocabulary and keywords. The effectiveness of calcitriol, paricalcitol, cinacalcet, and parathyroidectomy was compared and analysed. The mean calcium and parathormone (PTH) concentrations per patient in the group of paricalcitol increased by 1.27% and decreased by 35.14% (n = 248); in the group of cinacalcet decreased by 12.09% and 32.16% (n = 368); and in the group of parathyroidectomy decreased by 19.06% and 86.49% (n = 15) at the end of the study compared to the baseline (n = 244, n = 342 and n = 15), respectively. Paricalcitol, cinacalcet, and parathyroidectomy decreased the intact PTH level. Cinacalcet and parathyroidectomy lowered calcium levels in renal transplant patients with hypercalcaemia. Conversely, paricalcitol increased the serum calcium concentration. Cinacalcet seems to be a good candidate in the treatment of post-transplant hyperparathyroidism.

Kidney transplantation remains the best treatment for patients with end-stage kidney disease, and it could partially mitigate systemic disorders of mineral and bone metabolism caused by secondary hyperparathyroidism. However, persistent hyperparathyroidism is still observed in 30-60% of patients 1 year after kidney transplantation, leading to impairment of allograft function and a disturbance of mineral metabolism. The timing of parathyroidectomy varies among transplant centers because the possible negative effects of parathyroidectomy on allograft outcomes are still unclear. This review provides a comprehensive and detailed overview of the natural course of hyperparathyroidism following kidney transplantation and the effects of the timing and extent of parathyroidectomy on allograft function. It aims to provide useful information for surgeons to propose an appropriate intervention strategy to break the vicious cycle of post-kidney transplantation hyperparathyroidism and deterioration of allograft function.

Patients with primary hyperparathyroidism (pHPT) can develop persistent (P-pHPT) or recurrent (R-pHPT) disease after parathyroidectomy. Before recommending reoperation, recurrence must be accurately identified because of the high risk of complications. Our study evaluates 18F-fluorocholine (18F-FCH) PET/CT and 4D-CT integrated in PET/4D-CT in patients with P-pHPT/R-pHPT. Patients with P-pHPT/R-pHPT investigated by 18F-FCH PET/4D-CT between May 2018 and March 2021 were retrospectively included. Forty-two patients were included, 37 of whom underwent 4D-CT. The sensitivity and detection rate (DR%) were 95% and 88% for 18F-FCH PET/CT and 70% and 63% for 4D-CT, respectively. PET/CT and 4D-CT were concordant in 18/24 glands and concordant and positive in 15/24 (63%) glands. Discordant results were obtained for 6/24 glands. The surgical success rate was 65%. PET/CT showed significantly higher sensitivity than 4D-CT. Dynamic CT allowed the identification of no additional glands missed by PET/CT, and the combination of the 2 techniques did not improve the sensitivity or DR%. 18F-FCH PET/CT appears to be a valuable technique to accurately detect hyperfunctioning parathyroid tissue in patients with P-pHPT/R-pHPT and is better than 4D-CT. Except for cases with doubtful locations of PET targets that may require 4D-CT for surgical guidance, standard nonenhanced 18F-FCH PET/CT can be effectively recommended in patients with P-pHPT/R-pHPT before reoperation.

Bone disease is one of the most prominent complications after kidney transplantation. Bone diseases include osteoporosis, persistent secondary hyperparathyroidism, and avascular necrosis (AVN). We investigated the relationship between the polymorphisms of the vitamin D receptor (VDR) gene and bone diseases occurring after kidney transplantation.
The study consists of 234 kidney allograft recipients with a minimum follow-up of five years after kidney transplantation. Patients with glomerular filtration rates less than 30 mL/min/1.73m2, a history of parathyroidectomy, bisphosphonate use pre- or post-transplantation, and cinacalcet use posttransplantation excluded. We evaluated associations between the polymorphisms of the VDR gene (BsmI, TaqI, ApaI, FokI, and Cdx2), the first-year bone mineral density (BMD) scores, persistent secondary hyperparathyroidism, and AVN.
Patients with low BMD scores were significantly younger (P = 0.03) and had higher intact parathormone (iPTH) levels (P = 0.03). Cdx2 TT genotype significantly increases the risk of low BMD scores (OR: 3.34, P = 0.04). Higher phosphate levels were protective against abnormal BMD scores (OR: 0.53; P = 0.03). Patients with persistent hyperparathyroidism had significantly longer dialysis vintage and higher pretransplantation iPTH levels (P = 0.02 and P < 0.001, respectively). Cdx2, CT/TT, and ApaI CA/AA genotypes significantly increase the risk of persistent hyperparathyroidism (OR: 6.81, P < 0.001, OR: 23.32, P < 0.001, OR:4.01, P = 0.02, and OR: 6.30, P = 0.01; respectively). BsmI CT/TT genotypes were found to increase AVN risk with an HR of 3.48 (P = 0.03). Higher hemoglobin levels were also found to decrease AVN risk with an HR of 0.76 (P = 0.05).
Certain VDR gene polymorphisms are associated with a higher risk for bone diseases after kidney transplantation.

BACKGROUND: Hyperparathyroidism (HPT) is characterised by increased levels of parathyroid hormone (HPT), surgical excision being the only definitive curative option. After establishing the need for surgery, it is essential to identify the parathyroid glands in the preoperative period to use a minimally invasive approach. Negativity and / or discrepancy in first-line studies (ultrasound and Tc-99m MIBI parathyroid scintigraphy) require more accurate images to reduce the likelihood of bilateral cervical exploration or reintervention.
OBJECTIVE: a) To demonstrate the sensitivity of 18F-fluorocholine (18F-choline) positron emission tomography (PET)/4D computed tomography (4D CT) in HPT. b) To check whether there is a correlation between calcaemia and preoperative PTH versus size and early and late SUVmax (Standardized Uptake Value) of the gland, determined by 18F-choline PET/4D CT and c) to study the behaviour of parathyroid lesions with intravenous contrast (IV).
METHODS: A total of 28 patients were included between 2016 and 2019 in a single institution. Prospective observational cohort study. Correlations were analysed using Pearson\'s coefficient for variables with normal distribution and Spearman (rho) for those with non-normal distribution. Anatomopathological analysis was the benchmark standard to determine sensitivity was. A p<.05 was interpreted as significant. STATA 13 software was used.
RESULTS: Of the 28 patients who underwent 18F-choline PET/4D CT, 18 were operated. Of the 26 lesions diagnosed by 18F-choline PET/4D CT as suggestive of parathyroid lesions, 23 corresponded to glandular disease (adenoma or hyperplasia) establishing a sensitivity of 88.5%. There was a correlation between the patient\'s preoperative PTH and the maximum size of the gland on 18F-choline PET/4D CT. (Spearman=.66; p=.0014). The parathyroid lesions showed, in addition to IV contrast enhancement, distinctive behavioural characteristics identified as highly suggestive.
CONCLUSIONS: 18F-choline PET/CT 4D is an anatomical and functional study with high sensitivity in patients with HPT with negative or discrepant first-line studies. Preoperative PTH showed a correlation with maximum gland size on 18F-choline PET/CT 4D. Parathyroid lesions behave in a highly suggestive way and are enhanced by IV contrast.

Persistent/recurrent hyperparathyroidism occurs in 2%-5% of patients with sporadic primary hyperparathyroidism (PHPT). In this study, the incidence and time to recurrence in patients with single-gland disease (SGD), double adenomas (DAs), or four-gland hyperplasia (FGH) at initial parathyroidectomy were compared.
This retrospective review included adult patients with sporadic PHPT who underwent initial parathyroidectomy with intraoperative parathyroid hormone monitoring (IOPTH) from 1/2000 to 12/2016 with ≥6 mo follow-up. An abnormal parathyroid was defined by a gland weight of ≥50 mg. A concurrent serum calcium >10.2 mg/dL and parathyroid hormone >40 pg/mL was defined as persistent PHPT if present <6 mo and recurrent PHPT if present ≥6 mo postoperatively after initial normocalcemia.
Of 1486 patients, 1203 (81%) had SGD, 159 (11%) DA, and 124 (8%) FGH. Among the 3 groups, there was no difference in the percent decrease from the baseline or time of excision to final postexcision IOPTH levels between groups (79% versus 80% versus 80%, respectively; P = 0.954) or in the proportion of patients with a final IOPTH ≥40 (22% versus 18% versus 14%; P = 0.059). Overall, 22 (1.5%) had persistent PHPT and 26 (1.7%) had recurrent PHPT. Persistent PHPT was more frequent with DAs (6; 3.8%) than other groups (SGD: 16, 1.3%; FGH: 0; P = 0.02). At median follow-up of 33 mo (IQR, 18-60), there was no difference in recurrence rate (1.6% versus 2.5% versus 2.4%; P = 0.57) or median time (mo) to recurrence (SGD: 59 [IQR, 21-86], DAs: 36 [IQR, 29-58], FGH: 23 [IQR, 17-40]; P = 0.46).
Recurrent PHPT occurred in 1.7% of patients who underwent curative initial parathyroidectomy, with no difference in incidence or time to recurrence between groups based on the number of glands removed. Patients with DA more commonly had persistent PHPT, raising the possibility of unrecognized FGH.

Secondary hyperparathyroidism is a common acquired disorder seen in chronic renal failure. Its pathophysiology is mainly due to hyperphosphatemia and vitamin D deficiency and resistance. When medical treatment fails, subtotal and total parathyroidectomy with autotransplantation are the standard procedures, although both are associated with high recurrence rates.
4 patients experienced persistence and 9 relapse. The first 4 were subjected to reoperation after 6 months for the persistence of symptoms due to the finding of a supernumerary adenomatous gland while the remaining patients at the reoperation showed in 5 cases 2 more glands in over thymic position, and 4 an hyperplasia of the residual glandular tissue. A classic cervicotomy was sufficient to remove the residual parathyroid in patients with persistent hyperparathyroidism. For cases of recurrent hyperparathyroidism it was enough a medial approach and sometimes lateral for the complete excision of the hyperplastic tissue. The advent of the intraoperative technique of parathyroid hormone dosage allowed a better performance of the surgical technique for the last 3 patients undergoing reoperation. After reoperation all patients had immediate regression of clinical symptoms with normalization of serum calcium and PTH levels.
On the basis of these considerations, diagnostic imaging has a not negligible role because during the first intervention helps to have an idea of the possible location of the glands and thus to avoid the risk of recurrence and relapse due to ectopic or supernumerary tissue.