The Long Non-Coding BC200 Is a Novel Circulating Biomarker of Parathyroid Carcinoma.

Long non-coding RNAs (lncRNAs) are an important class of epigenetic regulators involved in both physiological processes and cancer development. Preliminary evidence suggested that lncRNAs could act as accurate prognostic and diagnostic biomarkers. Parathyroid cancer is a rare endocrine neoplasia, whose management represents a clinical challenge due to the lack of accurate molecular biomarkers. Our previous findings showed that human parathyroid tumors are characterized by a different lncRNAs signature, suggesting heterogeneity through the different histotypes. Particularly, we found that the lncRNA BC200/BCYRN1 could represent a candidate biomarker for parathyroid carcinomas (PCas). Here we aimed to extend our preliminary data evaluating whether BC200 could be an accurate non-invasive biomarker of PCas to support the clinical management of patients affected by parathyroid tumors at diagnosis, prognosis and follow-up. To provide a non-invasive point-of-care for parathyroid carcinoma diagnosis and follow-up, we analyzed BC200 expression in patients' serum through digital PCR. Our results show that BC200 counts are higher in serum from patients harboring PCa (n=4) compared to patients with parathyroid adenoma (PAd; n=27). Further, in PAd patients circulating BC200 levels are positively correlated with serum total calcium. Then, we found that BC200 is overexpressed in metastatic PCas (n=4) compared to non-metastatic ones (n=9). Finally, the lncRNA expression in PCa patients' serum drops are reduced after parathyroidectomy, suggesting its possible use in the post-operative setting for patients follow-up. Overall, these findings extend the knowledge on BC200 in parathyroid tumors, supporting its role as a useful biomarker for management of PCa.

Bone Turnover Markers in Response to Ultrasound-Guided Microwave Ablation for Primary Hyperparathyroidism.

Objective: To assess the efficacy and safety of ultrasound-guided microwave ablation (MWA) in the treatment of primary hyperparathyroidism (PHPT), and to investigate whether MWA can improve the bone turnover and renal function. Methods: A total of 20 consecutive PHPT patients with 21 parathyroid lesions treated with MWA in our center from May 2019 to March 2021 were recruited in this study. Serum parathyroid hormone (PTH), calcium and phosphorus levels before MWA and at 20 minutes, 4 hours, 1 day, 3 months, 6 months and 12 months after MWA were measured. Bone turnover biomarkers, renal function and lesion volume with volume reduction rate (VRR) before MWA and at the last follow-up were compared. Any complication related with MWA was evaluated. The technical and clinical success rates of MWA in the treatment of PHPT were calculated. Clinical success was defined as normal serum PTH and calcium without PHPT-associated manifestations at more than 6 months after ablation. Technical success was defined as complete ablation indicated by immediate postoperative contrast-enhanced ultrasound. Results: The serum PTH, calcium and phosphorus levels at their respective follow-up time points dropped significantly after MWA (P <0.05). The volume of parathyroid lesions at the final examination was significantly reduced, compared with pre-ablation volume (P <0.001), with a median VRR reaching 89%. The technical and clinical success rates were 100% and 63.6%, respectively. Substantial changes of bone turnover biomarkers were observed before and after MWA (P <0.05), but the differences in renal function were not statistically significant. No major complications were reported in all cases. Pre-MWA serum PTH, lesion volume, maximum diameter of lesion and ablation time were significantly different between patients with successful and failed MWA. Conclusions: PHPT can be effectively and safely treated by ultrasound-guided MWA, as proven by drop in serum PTH and reduction in the volume of parathyroid adenomas. Besides, MWA can impede bone remodeling to suppress hyperparathyroidism in the condition of PHPT.

Factors associated with negative 99mTc-MIBI scanning in patients with primary hyperparathyroidism.

OBJECTIVE: The objective was to evaluate the clinical and biological factors associated with negative 99mTc-MIBI scanning in patients with primary hyperparathyroidism (PHPT). METHODS: A retrospective observational study was designed in 195 patients (mean age: 59.2 ±â€¯13.0 years; 77% woman) with PHPT (calcium: 11,3 ±â€¯1,1 mg/dl and PTH: 218 ±â€¯295 pg/ml) studied in endocrinology setting between 2013 and 2020. An univariate and multivariate analysis was made to evaluate the clinical and biological factors associated with negative 99mTc-MIBI scanning. RESULT: 50 patients (26%) with negative 99mTc-MIBI scanning had lower PTH levels (146 ±â€¯98 vs. 244 ±â€¯334; p < 0,001), adenomas with smaller sonographic dimensions (maximum diameter: 1,2 ±â€¯0,4 vs. 1,7 ±â€¯0,9 cm; p = 0,001 and volume: 0,36 ±â€¯0,43 vs. 1,7 ±â€¯4,1 cm3; p < 0,001), localized more frequently in upper parathyroid glands (37% vs 14%; p = 0,005) and associated more frequently to thyroid nodules (72% vs 57%; p = 0,045) than patients with positive scanning. 116 patients were operated and parathyroid adenomas were smaller (maximum diameter: 1,3 ±â€¯0,5 vs. 1,9 ±â€¯1,1 cm; p = 0,008 and volume: 0,30 ±â€¯0,20 vs. 1,2 ±â€¯1,1 cm3; p < 0,001), less heavy (567 ±â€¯282 vs. 1470 ±â€¯1374 mgr.; p = 0,030) and were localized more frequently in upper situation (65% vs 16%; p < 0,001) than patients with positive scanning. In the multivariate analysis an independent association between negative 99mTc-MIBI scanning and size of removed adenoma ≤1 cm (OR: 5,77; IC 95: 1,46-22,71) and upper adenoma localization were observed (OR: 8,05; IC 95%: 2,22-29,16). CONCLUSIONS: One in four patients studied for PHPT had a negative 99mTc-MIBI scanning and were independent associated with size of adenoma ≤1 cm and upper adenoma localization.

Is extensive surgery really necessary in patients with parathyroid carcinoma? Single-centre experience and a brief review of the literature.

AIM: Parathyroid carcinoma (PC) represents a rare cause of primary hyperparathyroidism (PHPT). In this paper, among patients who underwent surgery for PHPT, we compared those with benign parathyroid disease with those affected by PC in terms of demographic and preoperative biochemical features. Moreover, we singularly described all 10 cases of PC treated at our Institution (including a case that occurred in a patient with tertiary hyperparathyroidism) and a brief review of the literature. MATERIAL AND METHODS: Patients undergoing surgery for PHPT in our Unit between 2003 and 2018 were retrospectively analysed. They were divided into two groups: Group A (benign parathyroid disease), Group B (PC). The case of PC that occurred in the patient with tertiary hyperparathyroidism was not included into the two groups. RESULTS: Three hundred and eight patients were included: 299 in Group A and 9 in Group B. The mean preoperative serum PTH value and mean preoperative serum calcium level were significantly higher in Group B than in Group A (P = 0.018, P = 0.027; respectively). Including the case of PC that occurred in the patient with tertiary hyperparathyroidism, 10 patients with PC were treated at our Institution. Among these, 3 underwent a re-exploration. Disease recurrence occurred in 1 (10%) patient, who developed a local recurrence and distant metastases. CONCLUSIONS: In the presence of PHPT characterized by particularly high preoperative levels of serum PTH and calcium this malignancy should be suspected. On the basis of our experience, we believe that extensive surgery is not always necessary. KEY WORDS: Hyperparathyroidism, Parathyroid carcinoma, Parathyroid surgery.

Locoregional recurrence of parathyroid carcinoma: how to identify this rare but fatal condition using ultrasonography.

Parathyroid carcinoma (PC) is a rare condition with propensity to relapse. The purpose of this study was to evaluate the sonographic findings of locoregional recurrences of parathyroid carcinoma, in order to facilitate diagnosis of this condition using ultrasound (US). This was a retrospective observational study including 21 patients confirmed with pathologically confirmed locoregional recurrence of parathyroid carcinoma. All patients had undergone preoperative US examination at a tertiary center. The imaging, clinical and laboratory data of each case were collected. Sonographic appearance of the largest lesion at each recurrence was evaluated by two experienced radiologists according to a pre-agreed protocol. Overall, 29 relapses occurred in 21 patients. The median age of the patients was 45 years (range 24-71 years). The median size of the largest recurrent lesion at each relapse was 1.8 cm (range 0.8-3.8 cm). Ultrasound images showed hypoechoic solid nodules in 28 relapses (96.6%), inhomogeneous echo-texture in 28 relapses (96.6%), intralesional echogenic septa-like structures in 21 relapses (72.4%), intralesional cystic change in two relapses (6.9%), infiltrative or blurred boundary in 20 relapses (69.0%), irregular shape in 22 relapses (75.9%), marked vascularization on color Doppler imaging in 19 relapses (65.5%), multiple lesions in 26 relapses (89.7%), contralateral recurrence in 3 relapses (10.3%), and subcutaneous recurrence in 10 relapses (34.5%). None of the recurrent lesions exhibited calcification. The total size of all the recurrent lesions at each relapse fairly correlated with the serum intact parathyroid hormone levels (r = 0.450; p = 0.014).

Primary hyperparathyroidism presenting as a brown tumor with hypercalcemia crisis in a second-trimester pregnant woman: A case report.

INTRODUCTION: Primary hyperparathyroidism (PHPT) in pregnancy is rare and unrecognized because the maternal physiological adaptations blurs the symptoms. There is no standard treatment strategy for maternal PHPT. Early diagnosis and interventions can prevent catastrophic consequences to the mother and fetus. PATIENT CONCERNS: A 31-year-old Chinese woman was admitted, due to a lump on the left lower leg for 4 months. The patient complained of mild pain in the left lower leg following exercise that could be relieved after a short rest. The patient was at 18 weeks of gestation, and the growth of the fetus was normal. The patient has a 3-year history of hypercalcemia and a 2-year history of nephrolithiasis. No family history of hypercalcemia and endocrine tumors were present. DIAGNOSIS: Laboratory tests demonstrated high serum calcium level of 3.84 mmol/L, parathyroid hormone 1393 pg/mL, alkaline phosphatase 488 µ/L. Ultrasound showed a 22.4 mm × 7.8 mm solid nodule in the left lower lobe of the thyroid gland. Based on these findings, the patient was diagnosed with PHPT. INTERVENTIONS: The patient accepted continuous renal replacement to reduce ironized calcium level. Parathyroidectomy was performed at the 19th week of gestation. Threatened abortion occurred 2 days after the surgery, and magnesium sulfate was used to prevent the abortion. Calcium gluconate, calcium carbonate and vitamin D3 were used to treat the hypocalcemia that occurred 5 days after the surgery. OUTCOMES: Pathology examination demonstrated the parathyroid adenoma. Abortion was prevented using magnesium sulfate and hypocalcemia was cured with calcium gluconate, calcium carbonate and vitamin D3. At 38-week of gestation, the patient (ionized calcium level: 2.16 mmol/L) delivered a healthy female baby weighing 2700 g with 10/10 Apgar. Till now, both the mother and infant showed no complications. CONCLUSION: Maternal PHPT is rare and challenging to diagnose, causing life-threatening complications to mother and fetus. Any decision regarding surgery for a pregnant woman with primary hyperparathyroidism is more complex than in men or nonpregnant women. The decision should be made based on the severity of hypercalcemia and symptoms.

Debulking surgery for functional pleural dissemination of parathyroid carcinoma-case report.

BACKGROUND: A rare cause of primary hyperparathyroidism (PHPT) is a parathyroid carcinoma. Hypercalcemia with an elevated parathyroid hormone (PTH) level seen in recurrent and metastasis disease cases is often refractory to medical therapy, thus surgical resection is recommended when possible. We performed debulking surgery for pleural dissemination of parathyroid cancer for improvement of symptoms in a patient with hypercalcemia. CASE PRESENTATION: A 30-year-old male with hypercalcemia was diagnosed with parathyroid cancer. Following surgery, intact PTH level elevation and hypercalcemia progression due to recurrent disease were noted. An active status of functional left pleural dissemination was revealed in 99mTc-methoxyisobutylisonitrile and somatostatin receptor scintigraphy results, but not in the area of pulmonary metastasis, and debulking surgery was performed. Thereafter, the PTH level was decreased temporarily and activities of daily living improved. CONCLUSION: Aggressive resection of metastatic disease in patients with a parathyroid carcinoma is taken into consideration to control hypercalcemia.

Double adenoma as a cause of primary hyperparathyroidism: Asymmetric hyperplasia or a distinct pathologic entity?

BACKGROUND: Primary hyperparathyroidism (PHPT) caused by double adenoma may carry a higher risk of failure to cure. We compared outcomes in single adenoma (SA), double adenoma (DA) and four-gland hyperplasia (HP). METHODS: Patients undergoing initial parathyroidectomy for PHPT were categorized by diagnosis. The primary outcome was persistent/recurrent disease postoperatively. RESULTS: Of 3408 patients, 81.3% had SA, 9.5% had DA, and 9.3% had HP. Rates of persistence/recurrence were 2.9%, 5.3%, and 4.5% in SA, DA, and HP, respectively (p = 0.281). Patients with persistence/recurrence had higher preoperative calcium (11.0 vs 10.7 mg/dl, p = 0.028) and PTH (96 vs 77 pg/ml, p = 0.015), and lower rates of IOPTH normalization (77% vs 96%, p < 0.001). On multivariable analysis, DA was associated with increased risk of persistent/recurrent disease (OR 3.0, p = 0.017). CONCLUSIONS: Most patients with DA are cured with removal of two glands, but approximately 5% experience disease persistence/recurrence. Low-normal final IOPTH was associated with lower risk of persistent/recurrent disease.

Reduction in parathyroid adenomas by cinacalcet therapy in patients with primary hyperparathyroidism.

INTRODUCTION: Cinacalcet is a calcimimetic that modulates the functions of calcium-sensing receptor and is currently used to treat patients with primary hyperparathyroidism (PHPT). Although it was reported that cinacalcet treatment reduced the size of hyperplastic parathyroid glands in patients with secondary hyperparathyroidism, whether or not cinacalcet treatment can reduce the size of parathyroid adenomas in patients with PHPT has been unknown. MATERIALS AND METHODS: We recruited nine (male: one, female: eight) patients with PHPT due to parathyroid adenomas who did not undergo parathyroidectomy. Cinacalcet was administered at a dose of 50 mg/day, and we evaluated the size of parathyroid adenomas (width × thickness) (mm2) using ultrasonography before and after 6 months of cinacalcet treatment. RESULTS: The mean age of the subjects was 58.1 ± 7.2 years old, and the mean serum intact parathyroid hormone (PTH) concentration was 134.8 ± 8.7 pg/ml. All participants showed hypercalcemia and osteopenia. After 6 months, the mean size of parathyroid adenomas was significantly decreased (baseline: 73.8 ± 33.4 mm2 vs. after 6 months: 52.5 ± 25.0 mm2, p = 0.045). Thus, 6-month cinacalcet treatment induced a 29% size reduction in parathyroid adenomas. Furthermore, the serum intact PTH concentration before cinacalcet treatment was positively correlated with the reduction in the size of parathyroid adenomas. CONCLUSION: The present study revealed that cinacalcet treatment reduces the size of parathyroid adenomas in patients with PHPT. The accumulation of more PHPT cases with cinacalcet therapy is required to confirm this finding.

Intraoperative parathyroid hormone (IOPTH) assay might be better than the second-generation assay in parathyroidectomy for primary hyperparathyroidism.

BACKGROUND: It is unclear whether the third-generation intraoperative parathyroid hormone assay can improve surgical outcomes over second-generation assay in primary hyperparathyroidism. We aimed to compare the rate of decrease and diagnostic accuracy between the two assays after parathyroid adenoma excision. METHODS: Consecutive patients undergoing parathyroidectomy with intraoperative parathyroid hormone were analyzed. Blood was drawn before and 10 minutes and 20 minutes after excision of the adenoma. The same blood sample was run simultaneously in the second-generation assays (Elecsys PTH STAT) and third-generation assays (Elecsys 1-84 PTH). Biochemical cure meant >50% intraoperative parathyroid hormone decrease at 10 minutes. Cure meant normocalcemia 6 months after operation. RESULTS: Relative to the second-generation assay, the value of the intraoperative parathyroid hormone level was less in the third-generation assay before excision (P < .001), at 10 minutes (P < .001), and at 20 minutes (P < .001). The intraoperative parathyroid hormone rate of decrease and the proportion of normalized post-excision intraoperative parathyroid hormone were greater in the third-generation assay (P < .001), but the prediction accuracy appeared similar between the 2 (91.5% vs 91.0%). Patients with worse renal function (estimated glomerular filtration rate <80mL/min/1.73m2) had a slower intraoperative parathyroid hormone decrease in the second-generation but not in the third-generation assay. CONCLUSION: Despite comparable accuracy between the two generations of assay, the third-generation assay might be better than the second-generation assay because of the more rapid decrease in the intraoperative parathyroid hormone and a greater percentage of normalized intraoperative parathyroid hormone, regardless of baseline renal function.

Progressive rise in the prevalence of asymptomatic primary hyperparathyroidism in India: Data from PHPT registry.

INTRODUCTION: Primary hyperparathyroidism (PHPT), a third common endocrine disorder, varies from asymptomatic disease, mostly seen in the West where routine biochemical screening is practiced, to the classical symptomatic disease mostly seen in the Eastern countries. We aimed to compare the demographic, clinical, biochemical measurements in patients with asymptomatic and symptomatic PHPT from the Indian PHPT registry. MATERIAL AND METHODS: Data of PHPT patients from the last 25 years (1995-2019) were analyzed for demographic, clinical presentation and biochemical measurements, and compared these characteristics between asymptomatic and symptomatic PHPT patients. RESULTS: Of the 554 patients, 54 (10%) patients had asymptomatic PHPT. There was a sharp rise in the proportion of asymptomatic PHPT patients of 3% in the first decade to 13% in the second decade of the century (p = 0.003). Patients with asymptomatic PHPT were significantly older (50 vs. 42 years; p < 0.0001) and had higher mean body mass index (27.8 vs. 23.5 kg/m2; p < 0.0001) compared to the symptomatic PHPT group. In addition, asymptomatic PHPT patients had significantly lower median plasma iPTH (180 vs. 370 pg/mL; p < 0.0001), serum alkaline phosphatase (119 vs. 172 IU/L; p < 0.0001), and parathyroid adenoma weight (1.0 vs. 2.62 g; p = 0.006) compared to the symptomatic PHPT group. CONCLUSION: Although symptomatic PHPT is still most prevalent (> 90%) in India with higher indices of the disease and tumor weights, there is a progressive rise in the prevalence of asymptomatic PHPT patients in the last decade. Improvements in calcium and vitamin D nutrition might account for this change as in the Western series.

Incidental finding of MEN-1 syndrome during staging and follow-up of breast carcinoma.

Type 1 multiple endocrine neoplasia (MEN-1) syndrome is an autosomal dominant disease, associated with germline mutations in the MEN-1 tumour suppressor gene (encoding the menin protein). Recent studies, through a better characterisation of the functions of the menin protein, have started to demonstrate how changes in this protein may be related to breast cancer. We present the case of a patient whose diagnosis of MEN-1 syndrome was made during treatment for a breast tumour-this diagnosis was obtained after finding multiple neoplastic lesions that fitted the MEN-1 syndrome spectrum, during the initial staging and subsequent follow-up of a breast tumour. In line with the growing evidence that links MEN-1 syndrome to breast cancer tumorigenesis, this case report highlights the following question: should we start screening this subset of patients earlier for breast cancer?

Correlation of perioperative biochemical variables with single adenoma weight in patients with primary hyperparathyroidism.

BACKGROUND: Single parathyroid adenoma is the main cause of primary hyperparathyroidism (PHPT), with surgery remaining the gold standard for its treatment. The ability to preoperatively predict the parathyroid adenoma size and could facilitate the decision about the extent of surgical exploration. It is reasonable to hypothesize that the perioperative levels of PHPT-related variables (i.e. calcium, parathormone, phosphate) may predict the adenoma weight or/and demonstrate whether the adenoma is successfully removed or not. Aim of this study is to explore the relationship between perioperative biochemical values and adenoma weight. Secondarily, we investigated the relationship between adenoma weight and uni-/bilateral neck exploration. METHODS: Retrospective study of all patients undergone surgery for primary hyperparathyroidism due to single adenoma in a tertiary university hospital in Germany during a 6-year period. Following variables were analyzed: preoperative serum calcium, phosphorus and parathormone, intraoperative parathormone before and after adenoma excision, intraoperative PTH decrease, postoperative serum calcium and parathormone (PTHpostop-pg/ml), calcium and PTH decrease. Bivariate correlations were calculated by the Spearman's correlation test at the 95% significance level. RESULTS: A total of 339 patients were included in the study. The median age of the patients was 60 years (range 21-90) and 77% were females. The median adenoma weight was 1 g (range 0.1-11). Adenoma weight correlated strong with maximum adenoma diameter (r = 0.72, p < 0.05), moderate with preoperative parathormone (r = 0.44) and parathormone decrease (r = 0.27), whereas there was no correlation with the intraoperative PTH decrease (r = 0.02). There was also a borderline (moderate to weak) correlation with pre- and postoperative calcium levels (r = 0.21 and r = 0.23 respectively) and a negative borderline correlation with phosphorus (r = - 0.21). Patients who required bilateral neck exploration, had significantly lighter adenomas (median weight 0.8 g vs 1.1 g, p = 0.005). CONCLUSIONS: We conclude that preoperative PTH levels may only serve as an approximate guide to adenoma weight, as direct preoperative prediction is not possible. Serum calcium levels, PTH and calcium decrease correlate only weak with adenoma weight. Patients who require bilateral neck exploration, have significantly (20-25%) lighter adenomas.

Evaluation of coagulation parameters in patients with parathyroid adenoma.

Parathyroid adenoma is responsible for 80-85% of cases of primary hyperparathyroidism. Increased fibrinogen levels in patients with adenoma may increase the risk of atherosclerosis and cardiovascular events. The aim of this study was to investigate the relationship between coagulation parameters and parathyroid adenoma. A prospective study included 28 female patients with parathyroid adenoma aged 40-88 years and 27 age-matched healthy controls. The coagulation parameters were assessed for each participant. The mean ages of the patient and control groups were 57.7 ± 10.9 and 53.3 ± 9.31 years, respectively. The mean level of protein S activity was 65.79 ± 13.78 in the patient group and 77.00 ± 15.72 in the control group, and the difference was statistically significant (p = 0.013). The mean fibrinogen levels of the patient and control groups were 338.78 ± 63.87 mg/dL and 304.30 ± 45.67 mg/dL, respectively, and a significant difference was found (p = 0.041). However, no significant difference was evident between the two groups with regard to the D-dimer (p = 0.238), aPTT (p = 0.645), INR (p = 0.406), protein C (p = 0.076), and AT-III (p = 0.180) levels. A positive correlation was observed between adenoma volume and fibrinogen in the patient group (r = 0.711, p = 0.001). The protein S levels were lower and the fibrinogen levels higher in the patients with parathyroid adenoma.

The genomic profile of parathyroid carcinoma based on whole-genome sequencing.

Parathyroid carcinoma (PC) is a rare endocrine malignancy with poor outcomes. Although some mutations such as CDC73 have been found in patients, the molecular mechanism of PC still needs extensive data to clarify. Whole-genome sequencing (WGS) was performed with frozen samples from 23 PC patients. Peripheral leukocytes were collected from 14 patients and served as controls. Somatic and germline gene alterations, copy number abnormalities and structural variants were detected. Inactivating CDC73 mutations were identified in 39.1% of patients, but only one germline inactivating mutation was found. Other cancer-related mutations identified in more than one case were MAF (2/23), NEB (6/23), NCOR1 (2/23), TTK (2/23), GRIN3A (4/23), TRIO (2/23), MAP1B (2/23), TJP2 (2/23) and FAM20A (2/23). In the seven wild-type CDC73 samples, the mutated genes were enriched in pathways involving antigen presentation, allograft rejection or autoimmune disease. More copy number variants were found in patients with cancer recurrence (P = .006) and CDC73 mutations (P = .022) than in those without these characteristics. PIK3CA loss was found in one sample, which also harboured a CDC73 mutation. Gene alterations in the PI3K/AKT/mTOR pathway were found in 78.3% (18/23) of tumours. The most prominent cancer-predisposing mutations were PDE4DIP (15/23), MAP3K1 (13/23) and CDC42EP1 (10/23). In conclusion, the PI3K/AKT/mTOR pathway may be pivotal in PC. CDC73 mutation correlated with an increased mutational burden and tumour relapse. PC patients with wild-type CDC73 harboured mutations relevant to antigen presentation and autoimmune diseases. A molecular classification based on the CDC73 mutation may help to manage follow-up and therapy for PC patients.

Effect of vitamin D nutrition on disease indices in patients with primary hyperparathyroidism.

In patients with primary hyperparathyroidism, the size of the adenoma is a major determinant of biochemical indices, disease severity, and manner of presentation. However, the large variation in adenoma weight, both within and between populations and a steady decline in parathyroid adenoma weights over time remain largely unexplained. Based on the results in a small number of patients almost two decades ago we proposed that vitamin D nutritional status of the patient explains both the disease manifestations and much of the variation in adenoma size. Accordingly, we examined the relationship between vitamin D nutrition, as assessed by serum levels of 25-hydroxyvitamin D, and parathyroid gland weight, the best available index of disease severity, in a large number of patients (n = 440) with primary hyperparathyroidism. A significant inverse relationship was found between serum 25-hydroxyvitamin D level and log adenoma weight (r = -0.361; p < 0.001). Also, the adenoma weight was significantly related directly to serum PTH, calcium, and alkaline phosphatase as dependent variables. In patients with vitamin D deficiency (defined as serum 25-hydroxyvitamin D levels 15 ng/mL or lower), gland weight, PTH, AP, and adjusted calcium were each significantly higher than in patients with 25-hydroxyvitamin D levels of 16 ng/mL or higher, but serum 1,25-dihydroxyvitamin D levels were similar in both groups. We interpret this to mean that suboptimal vitamin D nutrition stimulates parathyroid adenoma growth by a mechanism unrelated to 1,25-dihydroxyvitamin D deficiency. We conclude that variable vitamin D nutritional status in the population may partly explain the differences in disease presentation.

[Giant parathyroid adenoma: a rare cause of severe hypercalcemia].

We report the case of a 37-year-old woman that developed severe hypercalcemia due to a parathyroid gland mass. After the initial medical treatment, only a minimal reduction of calcemia was observed and her clinical condition worsened; thus, she required continuous renal replacement therapy (CRRT) that resulted in the normalization of calcium serum level. She then underwent a left thyroid lobectomy with exeresis of the associated parathyroid glands; the histological diagnosis revealed a giant parathyroid adenoma (GPA). CRRT, initially recommended only in case of severe refractory hypercalcemia poorly responsive to pharmacological approaches, is now being evaluated in the first line treatment of life-threatening cases, with or without associated acute kidney injury (AKI).

Severe hypercalcaemia of primary hyperparathyroidism: Could giant adenoma be the real culprit rather than carcinoma?

INTRODUCTION: Hypercalcaemic crisis is a rare manifestation of hyperparathyroidism and occurs in 1.6-6% of patients with primary hyperparathyroidism (pHPT). Although such high serum calcium levels (>14mg/dl) are attributed to malignancy, it is also associated with benign disease of the parathyroid glands. The aim of this study was to evaluate the clinical features and treatment modalities of patients with severe hypercalcaemia who underwent surgery for pHPT. METHODS: The medical records of 537 patients who underwent parathyroidectomy in our department for pHPT between 2005 and 2019 were reviewed retrospectively. Twenty-four (4.4%) of the patients were described as having severe hypercalcaemia. RESULTS: Among 24 patients, 71% were female and the mean age was 55.7 years (range: 40-71 years). The mean serum calcium level at time of diagnosis was 15.9mg/dl (range: 14-22.7mg/dl). According to postoperative pathology reports, solitary adenoma, parathyroid cancer and parathyromatosis were diagnosed with the rates of 87.5%, 8.3% and 4.1% respectively. The mean weight of the solitary parathyroid lesions was 14.9g (standard deviation: 8.9g, range: 4-38g). The mean longest diameter was 2.87cm (standard deviation: 1.4cm, range: 1-5.5cm). Serum calcium levels were within the normal range on the first postoperative day in 75% of the cases. CONCLUSIONS: Severe hypercalcaemia is a rare but urgent condition of pHPT and requires prompt management. Accelerated surgery after adequate medical treatment should be performed. It is important to emphasise that giant adenoma, which is a benign disease, may be a more common cause of severe hypercalcaemia than carcinoma, unlike previously thought.