Parathyroid carcinoma: a 22-year experience

A >50% Intraoperative Parathyroid Hormone Level Decrease Into Normal Reference Range Predicts Complete Excision of Malignancy in Patients With Parathyroid Carcinoma

INTRODUCTION

The mainstay of successful treatment for parathyroid carcinoma remains complete surgical excision. Although intraoperative parathyroid hormone (ioPTH) monitoring is a useful adjunct during parathyroidectomy for benign primary hyperparathyroidism, its utility for parathyroid carcinoma remains unclear.

METHODS

A retrospective review of 796 patients who underwent parathyroidectomy with ioPTH monitoring for primary hyperparathyroidism revealed 13 patients with parathyroid carcinoma on final pathology from two academic institutions. A systematic review yielded 5 additional parathyroid carcinoma patients. Complete excision of malignancy, or operative success (eucalcemia ≥6 mo. after parathyroidectomy); operative failure (persistent hypercalcemia <6 mo. after parathyroidectomy); and perioperative complications were evaluated. Comparison of the >50% ioPTH decrease alone to >50% ioPTH decrease into normal reference range was analyzed using Chi-squared, Kolmogorov-Smirnov, Kruskal-Wallis tests.

RESULTS

All 18 parathyroid carcinoma patients achieved a >50% ioPTH decrease, and 14 patients also had a final ioPTH level decrease into normal reference range. 93% of patients who met normal parathyroid hormone reference range had operative success, whereas only two of the four (50%) patients with parathyroid carcinoma with a >50% ioPTH decrease alone demonstrated operative success.

CONCLUSIONS

Parathyroidectomy guided by a >50% ioPTH decrease into normal reference range may better predict complete excision of malignant tissue in patients with parathyroid carcinoma compared to >50% ioPTH decrease alone. IoPTH monitoring should be used in conjunction with clinical judgment and complete en bloc resection for optimal treatment and success.

Acute pancreatitis and refractory hypercalcemia in the third trimester caused by parathyroid carcinoma

BACKGROUND

Hypercalcemia can be a rare contributor to acute pancreatitis (AP) in pregnancy. This is primarily due to primary hyperparathyroidism (PHPT), resulting from parathyroid carcinoma. We exhibited a case report to analyze the diagnosis and treatment during the onset of hypercalcemia-induced AP.

CASE PRESENTATION

A 32-year-old primigravida presented with acute pancreatitis near full-term gestation. Following a cesarean delivery, there was a reduction in serum amylase and peripancreatic exudate, but her serum calcium concentrations persistently elevated over 4.0 mmol/L. Interventions to lower the hypercalcemia were only temporarily effective, until a high serum parathyroid hormone (PTH) concentration of 1404 pg/mL was detected. Ultrasound revealed a 31 mm × 24 mm hypoechoic oval nodule in the left lower lobe of the thyroid gland. She underwent a parathyroidectomy, resulting in a dramatic decrease in serum PTH level, from preoperative levels of 2051 pg/mL to 299 pg/mL just 20 minutes after removal. Similarly, her serum calcium declined from 3.82 mmol/L to 1.73 mmol/L within 24 hours postoperatively. The final histopathology suggested parathyroid carcinoma.

CONCLUSION

When refractory hypercalcemia is present, serum PTH levels should be measured to determine PHPT. Parathyroidectomy is the optimal strategy for alleviating hypercalcemia and clarifying the underlying pathology.

Outcomes of bilateral axillo-breast approach robotic parathyroidectomy versus open parathyroidectomy for primary hyperparathyroidism: a single-institution retrospective study

Purpose

Bilateral axillo-breast approach robotic parathyroidectomy (BABA-RP) aims to remove overactive or enlarged parathyroid glands with no visible neck collar incision. In this study, we compared the safety and surgical outcomes of BABA-RP vs. those of an open surgery group to ascertain whether BABA-RP is a safe and feasible surgical approach for patients with primary hyperparathyroidism (pHPT).

Methods

This single-institution retrospective cohort study included 74 patients with primary HPT who underwent open parathyroidectomy (n = 37) or BABA-RP (n = 37) at our institution between November 2014 and March 2023. Patient demographics, biochemical cure rates, operative time, blood loss rates, and complication rates were examined and compared.

Results

The patients in the BABA-RP group were younger and had a longer mean operative time. Regarding complication events, 2 patients in the open surgery group and 1 patient in the BABA-RP group had transient hypoparathyroidism. All 74 patients achieved biochemical cure at <6 months, regardless of the approach used. Two patients in the BABA-RP group and 1 patient in the open surgery group had carcinoma on surgical pathology. All 3 patients with parathyroid carcinoma remained recurrence-free at 1-year follow-up.

Conclusion

Compared with the open procedure, BABA-RP is a safe and feasible procedure that provides an excellent biochemical cure rate for patients with pHPT and has superior cosmetic benefits with equivalent surgical outcomes.

Primary hyperparathyroidism in adults-(Part I) assessment and medical management: Position statement of the endocrine society of Australia, the Australian & New Zealand endocrine surgeons, and the Australian & New Zealand bone and mineral society

OBJECTIVE

To formulate clinical consensus recommendations on the presentation, assessment, and management of primary hyperparathyroidism (PHPT) in adults.

METHODS

Representatives from relevant Australian and New Zealand Societies used a systematic approach for adaptation of guidelines (ADAPTE) to derive an evidence-informed position statement addressing nine key questions.

RESULTS

PHPT is a biochemical diagnosis. Serum calcium should be measured in patients with suggestive symptoms, reduced bone mineral density or minimal trauma fractures, and in those with renal stones. Other indications are detailed in the manuscript. In patients with hypercalcaemia, intact parathyroid hormone, 25-hydroxy vitamin D, phosphate, and renal function should be measured. In established PHPT, assessment of bone mineral density, vertebral fractures, urinary tract calculi/nephrocalcinosis and quantification of urinary calcium excretion is warranted. Parathyroidectomy is the only definitive treatment and is warranted for all symptomatic patients and should be considered for asymptomatic patients without contraindications to surgery and with >10 years life expectancy. In patients who do not undergo surgery, we recommend annual evaluation for disease progression. Where the diagnosis is not clear or the risk-benefit ratio is not obvious, multidisciplinary discussion and formulation of a consensus management plan is appropriate. Genetic testing for familial hyperparathyroidism is recommended in selected patients.

CONCLUSIONS

These clinical consensus recommendations were developed to provide clinicians with contemporary guidance on the assessment and management of PHPT in adults. It is anticipated that improved health outcomes for individuals and the population will be achieved at a decreased cost to the community.

Is there a role for liquid biopsy in the surveillance of parathyroid carcinoma?

BACKGROUND

Parathyroid carcinoma is a rare malignancy with high recurrence rates. Liquid biopsy is a stratifying tool in disease recurrence/progression in other malignant processes. This study sought to assess the feasibility and application of liquid biopsy in parathyroid carcinoma and its impact on surveillance.

METHODS

Retrospective review of a prospectively maintained database of adults treated for parathyroid carcinoma at a tertiary care center (2017-2023). Demographics, clinical characteristics, and laboratory variables were collected. Circulating cell-free deoxyribonucleic acid enrichment and circulating tumor cell enumeration were obtained from serial blood samples.

RESULTS

A total of 25 patients were identified-64% were male patients, with a median age of 56 years (interquartile range 45-63). Fifty blood samples were collected postoperatively. At first, circulating tumor cell enumeration, 56% (14/25) of patients had no evidence of disease, and 32% (8/25) had distant metastasis. Median follow-up was 53 months (interquartile range 23-107). At the last follow-up, 40% (10/25) of patients were found to have distant metastasis. Serial circulating tumor cell enumeration was performed in 52% of patients, median highest circulating tumor cell was (interquartile range 1-22). Circulating cell-free deoxyribonucleic acid was assessed in 64% of patients (16/25). There was no difference in circulating tumor cells or circulating cell-free deoxyribonucleic acid between those with distant metastasis and those without distant metastasis. The most common mutation identified was TP53, present in 88% of circulating cell-free deoxyribonucleic acid samples with a mutation. Circulating cell-free deoxyribonucleic acid and parathyroid hormone levels were not found to have any association (r = -0.27, P = .39), but parathyroid hormone and circulating tumor cell had a linear relationship (r = 0.76, P < .001).

CONCLUSION

Liquid biopsy appears to be a feasible tool in parathyroid carcinoma surveillance. The relationship between circulating cell-free deoxyribonucleic acid and parathyroid hormone levels remains unclear, and the association between circulating tumor cell enumeration and parathyroid hormone levels may be impactful. The finding that TP53 mutation is more prevalent in patients with distant metastasis may impact further management.

Approach to the Patient With Parathyroid Carcinoma

Parathyroid carcinoma (PC) is usually associated with severe symptomatic primary hyperparathyroidism (PHPT) and accounts for less than 1% of all cases of PHPT and approximately 0.005% of all cancers. PC most commonly occurs as a sporadic disease and somatic CDC73 mutations can be detected in up to 80% of cases. Approximately 30% of patients harbor a germline mutation of the CDC73 gene. Preoperative diagnosis of PC is difficult because no disease-specific markers are available, and PC should be suspected in patients with severe hypercalcemia and end-organ complications. The diagnosis is based on the evidence of invasive tumor growth at histology and/or metastases. En bloc resection of the tumor, together with the ipsilateral thyroid lobe and adjacent structures, should be performed by an experienced surgeon when PC is suspected. This surgical approach reduces the risk of recurrence and metastasis and offers the highest chance of cure. Nonetheless, PC has a recurrence rate of 40% to 60% and, if feasible, multiple surgical procedures should be performed. When surgery is no longer an option, medical treatment is aimed to reduce hypercalcemia and target organ complications. Targeted agents have been effectively used in a few cases. We describe herein a patient with severe PHPT due to PC and provide a systematic diagnostic and treatment approach. A thorough review of the medical history, a typical clinical and biochemical phenotype and, in some cases, the revision of the histological examination provide the clues for the diagnosis of PC.

Comparison of prognosis after partial and total surgical resection for parathyroid carcinoma: an inverse probability of treatment weighting analysis of the SEER database

Background

Complete resection of the tumor and the ipsilateral thyroid lobe at the primary surgery is the "gold standard" for the treatment of parathyroid carcinoma (PC). However, differences in the overall survival (OS) of patients with PC who underwent partial and total surgical resection remain to be determined.

Methods

Data on patients with PC who underwent partial and total surgical resection were extracted from the Surveillance, Epidemiology and End Results (SEER) database (2000-2018). The X-tile software (https://medicine.yale.edu/lab/rimm/research/software/) was used to define the optimal cut-off values for continuous variables. The inverse probability of treatment weighting (IPTW) method was used to reduce the selection bias. IPTW-adjusted Kaplan-Meier curves and Cox proportional hazards models were used to compare the OS of patients with PC in the partial and total surgical resection groups.

Results

A total of 334 patients with PC were included in this study (183 and 151 in the partial and total surgical resection groups, respectively). The optimal cut-off values for age at diagnosis were 53 and 73 years, respectively, while that for tumor size was 34 mm. In both the Kaplan-Meier analysis and univariable Cox proportional hazards regression analysis before IPTW, the difference in OS between the partial and total surgical resection groups was not statistically significant (p>0.05). These findings were confirmed in the IPTW-adjusted Kaplan-Meier analysis and multivariate Cox proportional hazards regression analysis (p>0.05). Subgroup analysis revealed that total surgical resection was beneficial for OS only in the subgroup with unknown tumor size.

Conclusion

There was no significant difference in the prognosis of patients who underwent partial and total surgical resection. This finding may provide a useful reference for the treatment of PC.

Oligometastatic Parathyroid Carcinoma Presenting as Neck Pain: A Case Report

BACKGROUND

Parathyroid carcinoma (PC) is an exceedingly rare, slow-growing but progressive endocrine malignancy that represents a diagnostic and therapeutic challenge. Vertebral metastasis of PC is remarkable, with only 3 prior cases of spinal metastasis reported in the literature.

CASE DESCRIPTION

A 62-year-old woman presented with 1 week of neck pain radiating down her right arm. Cervical x-ray revealed a lytic lesion of the C4 vertebral body. Lab work revealed hypercalcemia with an elevated parathyroid hormone level. Computed tomography and magnetic resonance imaging revealed frank destruction of the C4 vertebral body and pedicles by PC. She was treated with corpectomy, mass excision, anterior cervical discectomy and fusion, postoperative radiotherapy, and nonspecific inhibitors of active tumor pathways. Her symptoms resolved postoperatively, and she has remained negative for reoccurrence at 15-month follow-up.

CONCLUSIONS

To the authors' knowledge, we report the first described cervical spine metastasis of PC. Additionally, we review the treatment of this rare neoplasm in an extremely rare location in the age of tumor sequencing and morphoproteomic analysis.

Molecular and Clinical Spectrum of Primary Hyperparathyroidism

Recent data suggest an increase in the overall incidence of parathyroid disorders, with primary hyperparathyroidism (PHPT) being the most prevalent parathyroid disorder. PHPT is associated with morbidities (fractures, kidney stones, chronic kidney disease) and increased risk of death. The symptoms of PHPT can be nonspecific, potentially delaying the diagnosis. Approximately 15% of patients with PHPT have an underlying heritable form of PHPT that may be associated with extraparathyroidal manifestations, requiring active surveillance for these manifestations as seen in multiple endocrine neoplasia type 1 and 2A. Genetic testing for heritable forms should be offered to patients with multiglandular disease, recurrent PHPT, young onset PHPT (age ≤40 years), and those with a family history of parathyroid tumors. However, the underlying genetic cause for the majority of patients with heritable forms of PHPT remains unknown. Distinction between sporadic and heritable forms of PHPT is useful in surgical planning for parathyroidectomy and has implications for the family. The genes currently known to be associated with heritable forms of PHPT account for approximately half of sporadic parathyroid tumors. But the genetic cause in approximately half of the sporadic parathyroid tumors remains unknown. Furthermore, there is no systemic therapy for parathyroid carcinoma, a rare but potentially fatal cause of PHPT. Improved understanding of the molecular characteristics of parathyroid tumors will allow us to identify biomarkers for diagnosis and novel targets for therapy.

Parathyroid carcinoma: Current management and outcomes – A systematic review

OBJECTIVE

Parathyroid carcinoma is rarely encountered in clinical practice. When faced with this clinical challenge, there is currently a paucity of evidence available for the optimal management of patients with parathyroid carcinoma. This systematic review synthesizes the available literature to evaluate the optimal management approach, thus providing guidance for future management.

METHODS

A systematic review was conducted according to PRISMA guidelines using Ovid MEDLINE, EMBASE, and PubMed databases for studies, published in English, reporting on parathyroid carcinoma. Full text of potentially eligible articles were reviewed by two authors independently and eligible studies selected. Treatment options and associated outcomes were evaluated. Descriptive statistics were used to describe pooled patient cohorts.

RESULTS

3203 articles were initially identified using the search criteria with 59 full-text articles then screened for eligibility. Seven articles, all retrospective studies, concerning 2307 patients (median 224/study). Parathyroidectomy alone was the most frequently utilised surgical approach across all studies, followed by en-bloc resection (with adjacent thyroid and/or nodal tissue). There was no difference in post-operative morbidity, mortality or survival between surgical approaches (p < 0.005). Patients who underwent either form of surgery had longer overall survival than those managed non-operatively (p < 0.005).

CONCLUSION

Surgical resection is the optimal treatment of parathyroid carcinoma. However there remains no consensus on the optimal extent of surgery, and as such future randomised prospective studies are necessary to evaluate the effects of different surgical approaches on morbidity, mortality and oncologic outcomes. Following resection, long-term surveillance with PTH is advised.

Parathyroid Carcinoma Presenting as Recurrent Primary Hyperparathyroidism and Neck Mass: A Case Report

Parathyroid carcinoma is a rare endocrine neoplasm that accounts for <1% of cases of primary hyperparathyroidism. The management of parathyroid carcinoma is a challenge due to the high rate of local recurrence of the tumour. We report the case of a middle-aged north Indian woman who presented with recurrent primary hyperparathyroidism due to parathyroid carcinoma. She presented with a recurrent palpable hard neck mass and underwent radical dissection of the neck six times. At the time of writing this report, she was referred for external beam radiotherapy to the neck. Parathyroid carcinoma is a rare malignancy with an indolent but tenacious course. Complete resection at the time of initial surgery determines the prognosis of the neoplasm. Chemotherapy and radiotherapy are usually ineffective. Hypercalcaemia needs to be aggressively managed. A multidisciplinary team is required to effectively manage parathyroid carcinoma.

Recurrence and mortality rate in an Italian multi-center case series of parathyroid atypical adenomas and carcinomas

Introduction

There are few data regarding the clinical outcome of patients with parathyroid carcinoma (PC) and atypical adenoma (AA) after surgery. Aim of our study was to investigate disease recurrence and mortality rate as well as their predictors in a series of patients with PC or AA.

Methods

Clinical and biochemical parameters, histological features, incidence of disease recurrence and mortality rate were retrospectively assessed in 39 patients (51% males, mean age 56.2 ± 17.2 years) diagnosed with PC (n=24) or AA (n=15) and followed up for 6.8 ± 5.0 years after surgery.

Results

No differences in baseline characteristics were registered between the two groups, except for higher KI67 values in PC than AA (6.9 ± 3.9% vs 3.4 ± 2.1%, p<0.01). Eight patients (21%) experienced recurrence after a mean follow-up of 5.1 ± 2.7 years, with higher relapse rate in PC than AA (25% vs 13%), though this difference did not reach statistical significance. Mortality rate was 10% in the whole sample, without significant differences between PC and AA. Relapsing cases had been undergone the most extensive surgery more frequently and they had a higher mortality rate in comparison to non relapsing patients (38% vs 6% and 38% vs 3%, respectively, p<0.03 for both). In comparison to survivors, deceased patients were submitted to the most extensive surgery more frequently (50% vs 9%), they were older (74.8 ± 4.6 vs 53.2 ± 16.3 years), and they had higher KI67 values (11.7 ± 4.9 vs 4.8 ± 2.8, p<0.03 for all comparisons).

Conclusions

During seven-year follow-up after surgery, no significant differences in recurrence and mortality rate were observed between PC and AA patients. Death was associated with disease relapse, older age and higher KI67 values. These findings suggest a similar and careful long-term follow-up in both parathyroid tumors, especially in older patients, and emphasize the need of further studies in large cohorts to throw light on this crucial clinical issue.

Papillary thyroid carcinoma associated with non‑functioning parathyroid carcinoma with Warthin's tumor of the parotid gland: A case report and brief literature review

Multiple neck pathologies occurring simultaneously are a rare condition. The present study describes an extremely rare case of papillary thyroid carcinoma, non-functioning parathyroid carcinoma (PC) and Warthin's tumor of the parotid gland. A 59-year-old male presented with a 3-month history of anterior neck swelling. The neck ultrasound revealed a left-sided thyroid nodule associated with pathological lymph nodes. There was a parotid gland mass. A fine-needle aspiration of the left parotid mass was not diagnostic, although the left thyroid nodule revealed a malignancy with metastasis to the left cervical group lymph nodes. The patient underwent total thyroidectomy, left central and left lateral cervical lymph node dissection. A superficial parotidectomy was also performed. A histopathological examination revealed three different pathologies: Papillary thyroid microcarcinoma, PC and Warthin's tumor. The simultaneous occurrence of a Warthin's tumor, papillary thyroid microcarcinoma and PC is an unusual condition. The concurrent findings of these three pathologies have not yet been reported in the literature, at least to the best of our knowledge. The synchronous findings of PTC, non-functioning PC and Warthin's tumor are extremely rare, yet possible. Surgical intervention remains the most appropriate treatment strategy.

Multiple Metastases of Parathyroid and Papillary Thyroid Carcinoma in a Female Patient Treated with Long-Term Hemodialysis

Parathyroid cancer is a rare, clinically aggressive malignancy with a prevalence of approximately 0.005% relative to all carcinoma cases and 1-5% among patients with primary hyperparathyroidism. Prognosis largely depends on the extent of the primary surgery. Non-radical surgical treatment increases the risk of local and distant metastases of the parathyroid cancer associated with limited treatment options. The combination of thyroid and parathyroid disorders has been described rather well for the general population; however, cases of parathyroid and thyroid carcinoma in the same patient are extremely rare (1 case per 3000 patients with parathyroid disorders). We present a rare clinical case of combination of parathyroid and thyroid cancers with metastases of both tumors to the neck lymph nodes in a woman with a mutation in the MEN1 gene (NM_130799.2): c.658T > C p.Trp220Arg (W220R), who has been exposed to radiation for 20 years before diagnosis of thyroid cancer and received renal replacement therapy with long-term hemodialysis before the diagnosis of parathyroid cancer. The patient underwent several surgeries because of metastases of the parathyroid cancer in the neck lymph nodes. Surgeons used intraoperative navigation methods (single-channel gamma detection probe, Gamma Probe 2, and fluorescence angiography with indocyanine green (ICG)) to clarify the volume of surgery. Currently, the patient is still in laboratory remission, despite the structural recurrence of tumors.

An extremely rare case of nonfunctioning parathyroid carcinoma occurring in a parathyroid adenoma

A 53-year-old woman with a 4-month history of fatigue and somnolence was referred to her local doctor because of the worsening of her symptoms. Marked increases in her serum calcium (13.0 mg/dl) and intact-parathyroid hormone (175 pg/ml) were found, she was referred to our hospital. On physical examination, there was a palpable 3 cm mass in her right neck. Ultrasonography showed a 1.9 × 3.6 cm circumscribed hypoechoic lesion in the caudal right lobe of the thyroid gland. There was very mild 99mTc-sestamibi scintigraphic accumulation. Her preoperative diagnosis was primary hyperparathyroidism due to parathyroid carcinoma, and surgery was performed. The tumor weighed 6300 mg and did not invade the surrounding area. The pathology showed a mixture of small cells thought to be parathyroid adenomas and large, pleomorphic nuclei and fissionable carcinomas. Immunostaining showed that the adenoma portion was PTH-positive, chromogranin A-positive, p53-negative, PAX8-positive, PGP 9.5-negative with a Ki 67 labeling index (LI) of 2.2%. Whereas the carcinoma portion was PTH-negative, chromogranin A-negative, p53-positive, PAX8-positive, PGP 9.5-positive with a Ki67 LI of 39.6%, showing a nonfunctioning aspect and highly malignant. Postoperatively, the patient is alive without recurrence 9 years later without hypercalcemia or recurrence. A case of nonfunctioning parathyroid carcinoma in an extremely rare parathyroid adenoma is reported.

Value of 99m Tc-MIBI SPECT/CT in the localization of recurrent lesions in patients with suspected recurrent parathyroid carcinoma

PURPOSE

Accurate preoperative localization of tumor-bearing lesions is crucial for the successful surgical management of suspected recurrent parathyroid carcinoma. The purpose of this study was to evaluate the diagnostic value of 99m-technetium-labeled methoxyisobutylisonitrile ( 99m Tc-MIBI) single-photon emission computed tomography/computed tomography (SPECT/CT) and cervical ultrasound, individually and in combination, for preoperative localization of recurrent/metastatic lesions. We also analyzed the value of 99m Tc-MIBI SPECT/CT in detecting ectopic lesions in patients with suspected recurrent parathyroid carcinoma.

METHODS

Twenty-nine patients with suspected recurrent parathyroid carcinoma were included in this retrospective cohort study. Patients underwent preoperative 99m Tc-MIBI SPECT/CT and cervical ultrasound. The reference standard was postsurgical histopathology. The sensitivity, specificity, positive predictive value (PPV), negative predictive value, and accuracy of the two diagnostic modalities alone and in combination were analyzed.

RESULTS

Of the 29 patients, histopathological results revealed 48 metastases/recurrent lesions in 26 patients. The diagnostic value of 99m Tc-MIBI SPECT/CT, cervical ultrasound, and the two modalities in combination were compared for the 27 patients who underwent new cervical surgery. Patient-level analysis of the combined use of 99m Tc-MIBI SPECT/CT and cervical ultrasound had the highest sensitivity (100.00%) and accuracy (96.30%). At the lesion level, 99m Tc-MIBI SPECT/CT had the highest specificity and PPV, at 100.00% respectively, whereas the combined use of 99m Tc-MIBI SPECT/CT and cervical ultrasound had the highest sensitivity, at 97.62%. Moreover, 99m Tc-MIBI SPECT/CT detected six ectopic lesions, and five of them showed increased 99m Tc-MIBI uptake.

CONCLUSIONS

The combined use of 99m Tc-MIBI SPECT/CT and cervical ultrasound is the most efficient strategy in the diagnosis of parathyroid carcinoma relapse, whereas 99m Tc-MIBI SPECT/CT is the preferred method for localizing and analyzing cervical and extra-cervical lesions before the new surgery.

Parathyroid Carcinoma: A National Cancer Database Analysis

INTRODUCTION

Parathyroid carcinoma is a rare diagnosis. The association of clinical and pathologic factors as well as treatment on overall survival (OS) is not well established.

METHODS

A retrospective review of patients with parathyroid carcinoma was performed using the National Cancer Database for patients diagnosed from 2004 through 2017. Clinical and demographic variables were assessed. A Cox proportional hazards model was used to assess for factors associated with survival. OS rates were determined for 5 and 10 y.

RESULTS

Data for 1057 patients were analyzed. The mean age at diagnosis was 57.5 y (standard deviation [SD] 14.0), and 542 (51.3%) were male. The median tumor size was 2.7 cm (interquartile range 2.0-3.7 cm). For the extent of surgery, 38 (3.6%) had no surgery, 568 (53.7%) had incomplete resection, 359 (34.0%) had complete resection, 58 (5.5%) had radical resection, and 34 (3.2%) did not have specified and were not used in the Cox proportional hazard regression model. For the cohort, 488 (46.2%) had lymph nodes resected with a mean of 5.5 (SD 6.6) removed. Of these, 32 (8.3%) had nodal metastases with one to six positive nodes. For adjuvant therapy, 159 (15.0%) had external beam radiation with a mean dose of 5463 cGy (SD 1464). Overall, 214 patients died (21.55%), and the estimated 5- and 10-y OS were 82.9% and 57.0%, respectively. In a Cox proportional hazard regression model, age at diagnosis as a continuous variable with hazard ratio (HR) 1.04, 95% confidence interval (CI) 1.01-1.06, P = 0.003, and extent of surgery as a categorical variable with no surgery as the referent group: incomplete surgery HR 0.05, 95% CI 0.01-0.19, P < 0.001; complete surgery HR 0.04, 95% CI 0.01-0.19, P < 0.001; radical surgery HR 0.10, 95% CI 0.02-0.45, P < 0.001; and tumor size as a continuous variable was not associated with OS with an HR of 1.00, 95% CI 0.99-1.00, P = 0.738.

CONCLUSIONS

Patient age and extent of surgery are modestly associated with survival for parathyroid carcinoma but not patient sex, nodal metastases, or adjuvant therapy in this cohort.

Margin Free Resection Achieves Excellent Long Term Outcomes in Parathyroid Cancer

Long-term outcomes of parathyroid cancer remain poorly documented and unsatisfactory. This cohort includes 25 consecutive parathyroid cancer patients with median follow-up of 10.7 years (range 4.1−26.5 years). Pre-operative work-up in the center identified a suspicion of parathyroid cancer in 17 patients. En bloc resection, including the recurrent laryngeal nerve in 4/17 (23.5%), achieved cancer-free resection margins (R0) in 82.4% and lasting loco-regional disease control in 94.1%. Including patients referred after initial surgery elsewhere, R0 resection was achieved in merely 17/25 (68.0%) of patients. Cancer-positive margins (R1) in 8 patients led to local recurrence in 50%. On multivariate analysis, only margin status prevailed as independent predictor of recurrence free survival (χ2 19.5, p < 0.001). Local excision alone carried a 3.5-fold higher risk of positive margins than en bloc resection (CI95: 1.1−11.3; p = 0.03), and a 6.4-fold higher risk of locoregional recurrence (CI95: 0.8−52.1; p = 0.08). R1-status was associated with an 18.0-fold higher risk of recurrence and redo surgery (CI95: 1.1−299.0; p = 0.04), and a 22.0-fold higher probability of radiation (CI95: 1.4−355.5; p = 0.03). In patients at risk, adjuvant radiation reduced the actuarial risk of locoregional recurrence (p = 0.05). When pre-operative scrutiny resulted in upfront oncological surgery achieving cancer free margins, it afforded 100% recurrence free survival at 5- and 10-year follow-up, whilst failure to achieve clear margins caused significant burden by outpatient admissions (176 vs. 4 days; χ2 980, p < 0.001) and exposure to causes for concern (1369 vs. 0 days; χ2 11.3, p = 0.003). Although limited by cohort size, our study emphasizes the paradigm of getting it right the first time as key to improve survivorship in a cancer with excellent long-term prognosis.

Surgical Aspects of Primary Hyperparathyroidism

Parathyroidectomy (PTX) is the treatment of choice for symptomatic primary hyperparathyroidism (PHPT). It is also the treatment of choice in asymptomatic PHPT with evidence for target organ involvement. This review updates surgical aspects of PHPT and proposes the following definitions based on international expert consensus: selective PTX (and reasons for conversion to an extended procedure), bilateral neck exploration for non-localized or multigland disease, subtotal PTX, total PTX with immediate or delayed autotransplantation, and transcervical thymectomy and extended en bloc PTX for parathyroid carcinoma. The systematic literature reviews discussed covered (i) the use of intraoperative PTH (ioPTH) for localized single-gland disease and (ii) the management of low BMD after PTX. Updates based on prospective observational studies are presented concerning PTX for multigland disease and hereditary PHPT syndromes, histopathology, intraoperative adjuncts, localization techniques, perioperative management, "reoperative" surgery and volume/outcome data. Postoperative complications are few and uncommon (<3%) in centers performing over 40 PTXs per year. This review is the first global consensus about surgery in PHPT and reflects the current practice in leading endocrine surgery units worldwide. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Treatment and outcome of metastatic parathyroid carcinoma: A systematic review and pooled analysis of published cases

Background

Parathyroid carcinoma (PC) is an extremely rare malignant tumor with an incidence of about 6 new cases per 10 million inhabitants per year. While several papers have been published on treatments and outcomes of PC patients with loco-regional disease, little is known about the prognosis, treatment strategies, and prognostic factors of patients with distant metastasis.

Materials and methods

We performed a systematic review and a pooled analysis of histopathologically confirmed PC cases published in literature using the following keywords: “metastasis–metastatic–secondary nodes” AND “parathyroid carcinoma”. Original case reports and case series reporting metastatic parathyroid carcinoma were included. Data from 58 articles were extracted in a piloted form by five reviewers on a shared database.

Results

Seventy-nine patients with metastatic PC were identified between 1898 and 2018. Ten (13%) patients had synchronous metastases, while metachronous metastases occurred in 43 (54%) patients. The remaining 26 patients developed metastatic disease concomitantly to local recurrence. Primary hyperparathyroidism guided the diagnosis of metastatic recurrence in 58 (73%) patients. Surgery was the main primary approach adopted, as it was performed in 43 (54%) patients. Twenty (25%) patients underwent systemic antineoplastic therapy, consisting of chemotherapy, immunotherapy, tyrosine kinase inhibitors, and hexestrol therapy. Bone resorption inhibitors had a limited efficacy in the long-term control of hypercalcemia. After a median follow-up of 37.5 months, 43 (55%) patients died, 22 (51%) due to the consequences of uncontrolled PHPT. The median overall survival was 36 months (range: 1–252). Surgery was associated with a better OS (HR 0.48, 95% CI 0.26–0.88), whereas bone metastases represented a negative prognostic factor (HR 2.7, 95% CI 1.4–5.2).

Conclusion

Metastatic PC has a relatively poor prognosis. The main goals of treatment are to counteract tumor growth and control hypercalcemia. Surgery of metastases is the best approach to achieve rapid control of PHPT and longer survival. Target therapies and immunotherapy deserve to be extensively tested in metastatic PC and strategies to better control hypercalcemia should be implemented.

The Clinical Features and Treatment Strategy of Parathyroid Cancer: A Retrospective Analysis

Objective

To review the features and treatment of parathyroid cancer in our series. Explore the suitable extent of initial surgery and the effect of adjuvant radiotherapy in local recurrence.

Methods

Seven cases of parathyroid cancer presented from 2014 to 2021. The presenting features, diagnosis, and treatment are presented.

Results

Only two patients had multiple manifestations of hypercalcemia. Marked hypercalcemia, which was revealed to be an average of 13.9 mg/dl (range from 11.8 mg/dl to 15.8 mg/dl), was observed in four patients (57%). The others' serum calcium levels were in the normal range with an average of 9.9 mg/dl (range from 8.6 mg/dl to 10.8 mg/dl). All seven patients had hyperparathyroidism with an average of 733 pg/ml (range from 113 pg/ml to 3193 pg/ml). En bloc resection was performed in two patients with neighboring structure invasion, and four patients with complete tumor capsules underwent tumor resection with limited resection of the thyroid gland. Postoperative adjuvant radiotherapy appeared unsuccessful for local recurrence.

Conclusion

High calcium, high PTH, parathyroid occupation by ultrasound, and intraoperative invasion should be considered to have the possibility of parathyroid cancer. Open surgery is recommended and protecting tumor integration is the elementary surgery principle. The initial surgical extent should be decided by the invasion of the tumor. When PC has a local recurrence, the debulking surgery and adjuvant radiotherapy are always fake.

Parathyroid carcinoma: Single centre experience

OBJECTIVE

Parathyroid Carcinoma is a rare malignant neoplasm, accounting for less than 1% of primary hyperparathyroidism cases. Parathyroid carcinomas are characterized by markedly elevated levels of PTH, severe hypercalcemia and established target organ damage. The authors report the experience of a single centre regarding the management and outcome of patients with parathyroid carcinomas and revise relevant literature.

DESIGN

Retrospective review of all patients with parathyroid carcinoma evaluated at a tertiary oncologic centre from 1991 until 2021.

RESULTS

Seventeen patients were identified (10 males), with a mean age at diagnosis of 53 ± 16 years and a median follow-up of 16.5 years. Most patients presented with hypercalcemia (n = 15), with a mean serum calcium concentration of 13.5 mg/dl (9.6-16.5) and mean PTH of 1173 pg/ml (276-2500). Hyperparathyroidism-mediated organ damage was observed in most patients (n = 16), with predominant renal (n = 12) and skeletal (n = 9) complications. En bloc surgical resection was performed in nine patients. Three patients underwent adjuvant radiotherapy. Recurrence was observed in 8 cases (47.1%) after a median of 24 months following surgery and no independent predictors of recurrence were identified. The overall survival and disease specific survival at 5-year was 88% and 94%, respectively. CDC73 mutations were present in 38.5% of analysed patients and one patient was diagnosed with MEN1.

CONCLUSION

Parathyroid carcinoma is associated with a significant rate of recurrence and limited effective treatment beyond initial complete surgical resection. Therefore, preoperatively high index of suspicion is paramount to optimize patient care. This is, to our knowledge, the largest Portuguese cohort published so far.

Association of Parathyroid and Differentiated Thyroid Carcinomas: A Narrative Up-To-Date Review of the Literature

Aim: Parathyroid carcinoma (PC) is a rare endocrine malignancy that represents 0.005% of all malignant tumors. Associated PC and differentiated thyroid carcinoma (DTC) is an exceptionally rare condition, and the preoperative diagnostics and proper treatment are challenging. Almost all PCs and the majority of DTCs are diagnosed postoperatively, making correct surgical treatment questionable. Specific guidelines for parathyroid and thyroid carcinomas association treatment are lacking. The purposes of our study were to identify the association between parathyroid and thyroid carcinomas, to analyze the available published data, and to evaluate the possible relationship between preoperative diagnostic and surgical decision-making, and outcome-related issues. Material and methods: We performed a literature review of several databases from the earliest records to March 2022, using controlled vocabulary and keywords to search for records on the topic of PC and WDTC pathological association. The reference lists from the initially identified articles were analyzed to obtain more references. Results: We identified 25 cases of PC and DTC association, 14 more than the latest review from 2021. The mean age of patients was 55, with a female to male ratio of about 3:1. Exposure to external radiation was identified in only one patient, although it is considered a risk factor the development of both PC and DTC. The preoperative suspicion of PC was stated by the authors in only 25% of cases, but suspicion based on clinical, laboratory, ultrasound (US), and fine needle aspiration (FNA) criteria could have been justified in more than 50% of them. With neck ultrasound, 40% of patients presented suspicious features both for PC and thyroid carcinoma. Intra-operatory descriptions of the lesions revealed the highest suspicion (83.3%) of PC, but en bloc resection was recommended and probably performed in only about 50% of the cases. Histopathological examinations of the thyroid revealed different forms of papillary thyroid carcinoma (PTC) in most cases. Postoperative normocalcemia was achieved in 72% of patients, but follow-up data was missing in about 25% of cases. Conclusion: Associated PC and DTC is an exceptionally rare condition, and the preoperative diagnostic and treatment of the patients is a challenge. However, in most cases pre- and intraoperative suspicious features are present for identification by a highly specialized multidisciplinary endocrine team, who can thus perform the optimal treatment to achieve curability.

Tumor size rather than the thyroid invasion affects the prognosis of parathyroid carcinoma without lymph node or distant metastasis

PURPOSE

This study aimed to explore the prognostic value of thyroid invasion of parathyroid carcinoma without lymph node or distant metastasis.

METHODS

Two hundred and nine cases of parathyroid carcinoma from the SEER (1989-2014) were eligible for this study. A Chi-squared test, t test, X-tile, Kaplan-Meier curves, and multivariate Cox proportional hazard regression were used for analysis.

RESULTS

Thyroid invasion, sex, race, age, radiation, and surgery were not significantly associated with cancer-specific survival by multivariate analysis. However, tumor size ≥ 4 cm was significantly associated with worse cancer-specific survival (P < 0.001).

CONCLUSION

Thyroid invasion, which was the criterion for T₁ and T₂ staging criteria of parathyroid carcinoma according to the AJCC, did not affect the prognosis of patients with parathyroid carcinoma without local lymph node or distant metastasis. Our study indicates that a tumor size ≥ 4 cm may be an appropriate indicator of T₁ and T₂ cancer staging.

Parathyroid Carcinoma: Incidence, Survival Analysis, and Management: A Study from the SEER Database and Insights into Future Therapeutic Perspectives

Introduction: Parathyroid carcinoma (PC) is an extremely rare entity, with a frequency of 0.005% of all malignancies. Most data related to this rare disease are limited to case series and a few database studies. We present a large database study that aims to investigate the demographic, clinical, and pathological factors, prognosis, and survival of PC. Methods: Data of parathyroid carcinoma were extracted from the Surveillance, Epidemiology, and End Results (SEER) diagnosed between 1975 and 2016. Results: PC had a slightly higher incidence in men (52.2%, p < 0.005), the majority of cases affected Caucasians (75.4%, p < 0.005), and the mean age at diagnosis was 62 years. Histologically, 99.7% were adenocarcinomas not otherwise specified (p < 0.005), well-differentiated (p < 0.005), and 2−4 cm (p < 0.001) in size among the patients with available data. In cases with staging provided, most PC were organ-confined (36.8%, p < 0.001). Lymph nodes were positive in 25.2% of cases where lymph node status was reported. The main treatment modality was surgery (97.2%), followed by radiation alone (2%), and very few received chemotherapy alone (0.8%), p < 0.005. Five-year follow-up was available for 82.7% of the cases. Those who underwent surgery only or radiation alone had 5-year survivals of 83.8% and 72.2%, respectively (p < 0.037). Multivariable analysis identified tumor size >4 cm, age > 40 years, male sex, Caucasian race, distant spread, and poorly differentiated grade as independent risk factors for mortality (p < 0.001). Conclusion: PC is a very rare tumor mostly affecting Caucasian individuals in the fifth decade. Older age, poor histologic differentiation, and distant metastasis are associated with a worse prognosis. Surgical resection offers the best survival outcome. To better understand the pathogenesis and factors affecting survival, all PC patients should be enrolled in national and international registries.

Overview of the 2022 WHO Classification of Parathyroid Tumors

The 2022 WHO classification reflects increases in the knowledge of the underlying pathogenesis of parathyroid disease. In addition to the classic characteristic features of parathyroid neoplasms, subtleties in histologic features which may indicate an underlying genetic abnormality reflect increased understanding of the clinical manifestations, histologic, and genetic correlation in parathyroid disease. The importance of underlying genetic aberrancies is emphasized due to their significance to the care of the patient. Traditionally, the term "parathyroid hyperplasia" has been applied to multiglandular parathyroid disease; however, the concept of hyperplasia is generally no longer supported in the context of primary hyperparathyroidism since affected glands are usually composed of multiple "clonal" neoplastic proliferations. In light of these findings and management implications for patient care, the 2022 WHO classification endorses primary hyperparathyroidism-related multiglandular parathyroid disease (multiglandular multiple parathyroid adenomas) as a germline susceptibility-driven multiglandular parathyroid neoplasia. From such a perspective, pathologists can provide additional value to genetic triaging by recognizing morphological and immunohistochemical harbingers of MEN1, CDKN1B, MAX, and CDC73-related manifestations. In the current WHO classification, the term "parathyroid hyperplasia" is now used primarily in the setting of secondary hyperplasia which is most often caused by chronic renal failure. In addition to expansion in the histological features, including those that may be suggestive of an underlying genetic abnormality, there are additional nomenclature changes in the 2022 WHO classification reflecting increased understanding of the underlying pathogenesis of parathyroid disease. The new classification no longer endorses the use of "atypical parathyroid adenoma". This entity is now being replaced with the term of "atypical parathyroid tumor" to reflect a parathyroid neoplasm of uncertain malignant potential. The differential diagnoses of atypical parathyroid tumor are discussed along with the details of worrisome clinical and laboratory findings, and also features that define atypical histological and immunohistochemical findings to qualify for this diagnosis. The histological definition of parathyroid carcinoma still requires one of the following findings: (i) angioinvasion (vascular invasion) characterized by tumor invading through a vessel wall and associated thrombus, or intravascular tumor cells admixed with thrombus, (ii) lymphatic invasion, (iii) perineural (intraneural) invasion, (iv) local malignant invasion into adjacent anatomic structures, or (v) histologically/cytologically documented metastatic disease. In parathyroid carcinomas, the documentation of mitotic activity (e.g., mitoses per 10mm²) and Ki67 labeling index is recommended. Furthermore, the importance of complete submission of parathyroidectomy specimens for microscopic examination, and the crucial role of multiple levels along with ancillary biomarkers have expanded the diagnostic workup of atypical parathyroid tumors and parathyroid carcinoma to ensure accurate characterization of parathyroid neoplasms. The concept of parafibromin deficiency has been expanded upon and term "parafibromin deficient parathyroid neoplasm" is applied to a parathyroid neoplasm showing complete absence of nuclear parafibromin immunoreactivity. Nucleolar loss is considered as abnormal finding that requires further molecular testing to confirm its biological significance. The 2022 WHO classification emphasizes the role of molecular immunohistochemistry in parathyroid disease. By adopting a question-answer framework, this review highlights advances in knowledge of histological features, ancillary studies, and associated genetic findings that increase the understanding of the underlying pathogenesis of parathyroid disease that are now reflected in the updated classification and new entities in the 2022 WHO classification.

Parathyroid Carcinoma: a Review

Parathyroid cancer is a rare endocrine malignancy with only a few thousand cases reported worldwide. As a result, there exists considerable controversy regarding the various aspects of this disease, viz., etiology, diagnosis, and management. We hereby attempt to review the literature on parathyroid carcinoma (PC) and summarize the practices based on the current evidence available. The majority of the PC are sporadic although an association with hyperparathyroidism-jaw tumor syndrome, multiple endocrine neoplasia (MEN) 1 and 2, and isolated familial hyperparathyroidism has been shown. As preoperative diagnosis is challenging, PC should be suspected in patients presenting with a neck mass with signs and symptoms of invasion to surrounding structures. Skeletal and renal symptoms are often associated with PC as presenting complaints. The biochemical parameters are more pronounced in the case of PC compared with benign countpart. Due to its rarity, the American Joint Committee of cancer control (AJCC) acknowledges that as yet a clear distinct staging system to prognosticate the disease would be premature. Complete excision with negative margins at first surgery offers the best chance of cure. The role of radiotherapy (RT) is still unclear; however few series have suggested a better locoregional control with adjuvant RT. Recurrences are common and are most significantly associated with an incomplete clearance at initial surgery. Surgical salvage of recurrent/metastatic disease with medical management of hypercalcemia is the treatment of choice. Large prospective studies and trials need to be conducted to understand the pathology better and improve management protocols; however this is a challenge due to rarity of cases.

Hsa_circ_0005729 enhances accuracy in diagnosing parathyroid carcinoma

BACKGROUND

Parathyroid carcinoma (PC), often misdiagnosed as a parathyroid adenoma (PA), is prone to local relapse due to the initial surgery being restricted to parathyroid lesions instead of en bloc resection of parathyroid lesions with negative incision margins. However, it is very challenging to distinguish PC from PA preoperatively; hence, this study investigated an effective biomarker for increasing accuracy in PC diagnosis.

METHOD

First, the differentially expressed circular RNAs between three PC tissues and three PA tissues were screened by high-throughput circular RNA sequencing, and the expression of hsa_circ_0005729 was verified by qRT-PCR in 14 patients with PC and 40 patients with PA. Secondly, the receiver operating characteristic curve and the area under the curve (AUC) were used to analyze the diagnostic efficiency of hsa_circ_0005729 in PC by combining with laboratory data. Thirdly, RNF138mRNA, the corresponding linear transcript of hsa_circ_0005729, was measured, and the relationship between hsa_circ_0005729 and RNF138 mRNA was analyzed in patients with PA and patients with PC.

RESULTS

Hsa_circ_0005729 expression was significantly higher in patients with PC than in patients with PA. Serum calcium (P = 0.045), alkaline phosphatase (ALP) (P = 0.048), and creatinine levels (P = 0.036) were significantly higher in patients with PC than in patients with PA. The AUC increased to 0.86 when hsa_circ_0005729 combined with serum calcium, creatinine, and ALP. In addition, hsa_circ_0005729 was positively correlated with RNF138 mRNA in patients with PA but not in patients with PC.

CONCLUSION

The novel circular RNA hsa_circ_0005729 was found to have a higher expression in patients with PC, indicating its usefulness for distinguishing PC from PA.

Giant parathyroid tumours in primary hyperparathyroidism: a systematic review

PURPOSE

Giant parathyroid adenoma (GPA) can present with severe biochemical derangement similar to the clinical presentation of parathyroid carcinoma (PC). This study aims to present the current evidence on surgical management of GPAs in primary hyperparathyroidism.

METHODS

A systematic review of the literature on GPAs was conducted following the PRISMA guidelines. Data on clinical, biochemical, preoperative diagnostic, and surgical methods were analysed.

RESULTS

Sixty-one eligible studies were included reporting on 65 GPAs in eutopic, ectopic mediastinal, and intrathyroidal locations (61.5%, 30.8%, and 7.7%, respectively). A palpable neck mass was present in 58% of GPAs. A total of 90% of patients had symptoms including fatigue, skeletal pain, pathological fracture, nausea, and abdominal pain. Ninety percent of patients had significant hypercalcaemia (mean 3.51 mmol/L; range: 2.59-5.74 mmol/L) and hyperparathyroidism with PTH levels on average 14 times above the upper limit of the normal reference. There was no correlation between the reported GPA size and PTH nor between GPA weight and PTH (p = 0.892 and p = 0.363, respectively). Twenty-four percent had a concurrent thyroidectomy for suspicious features, intrathyroidal location of GPA, or large goitre. Immunohistochemistry such as Ki-67, parafibromin, and galectin-3 was used in 18.5% of cases with equivocal histology. Ninety-five percent of GPAs were benign with 5% reported as atypical adenomas.

CONCLUSION

The reported data on GPAs are sparse and heterogeneous. In GPAs with suspicious features for malignancy, en bloc resection with concurrent thyroidectomy may be considered. In the presence of equivocal histological features, ancillary immunohistochemistry is advocated to differentiate GPAs from atypical adenomas and PCs.

Parathyroid Carcinoma All-In-One, a Rare Life-Threatening Case With Multiple Systemic Manifestations: Case Report and Review of the Literature

Parathyroid carcinoma (PC) is an extremely rare disease. Although it may occasionally occur in genetic syndromes, it is more often sporadic. It is usually associated with a consistent secretion of PTH, causing severe hypercalcemia and potentially all clinical conditions due to primary hyperparathyroidism. Management of PC can be challenging: some clinical, biochemical, and radiological features may be useful, but the final diagnosis of malignancy strictly relies on histological criteria. To date, radical surgery is the first-choice treatment and is the only effective therapy to control hypercalcemia and other clinical manifestations. On the other hand, chemo- or radiotherapy, local treatments, or novel drugs should be reserved for selected cases. We report an exceptionally unusual case of life-threatening PC, associated with several systemic manifestations: moderate pancreatitis, portal thrombosis, kidney stones, brown tumors, osteoporosis, hungry bone syndrome (HBS), chondrocalcinosis, neuropathy, and depression. The clinical case also represents an opportunity to provide a review of the recent literature, associated with a complete evaluation of the main diagnostic and therapeutic approaches.

Diagnosis and treatment of liver metastases of parathyroid carcinoma

INTRODUCTION

Parathyroid carcinoma (PC) is a very rare endocrine malignancy occurring in less than 1% of all cases of primary hyperparathyroidism (pHPT). The liver is the second most common target organ for distant metastases of PC, but no guidelines are available for the diagnosis and treatment of liver metastases. In this study, we attempted to summarize the characteristics of the diagnosis and treatment of liver metastases based on our patients and other cases reported in the literature.

MATERIALS AND METHODS

The files of all patients diagnosed with PC with liver metastases summarized at our center between 2000 and 2022 were reviewed, and three datasets from Medline, Web of Science, and Embase were systematically searched to identify relevant articles.

RESULTS

Three patients with liver metastases from our center and 11 patients from the literature were included in the study. All patients had pHPT with borderline remission of hypercalcemia after each operation. A total of 71.4% of the patients' liver lesions were found by abdominal CT scans, while 35.7% were found by MRI, PET-CT, and fine-needle aspiration biopsy (FNAB), which were also helpful for diagnosis. Eight of nine patients (88.9%) who underwent surgery, radiofrequency ablation (RFA), or transcatheter arterial embolization (TAE) were alive, and only one postoperative patient died after a follow-up of 60 months.

CONCLUSIONS

PC is a rare malignant tumor prone to recurrence and metastasis, and postoperative reviews should be carried out routinely. Abnormally elevated parathyroid hormone (PTH) and serum calcium can indicate recurrence or metastasis. Enhanced CT and MRI can provide valuable support for the diagnosis of liver metastases, but whether [18F]FDG-PET-CT, [18F]FCH-PET-CT, or [11C]choline-PET-CT can be used as a diagnostic basis requires further study. Resection of liver metastases, segmental hepatectomy, or RFA can significantly improve patients' symptoms.

Parathyroid Carcinoma and Ectopic Secretion of Parathyroid hormone

The most common causes of hypercalcemia are primary hyperparathyroidism (PHPT) and malignancy. Parathyroid carcinoma (PC), causing a severe PHPT, is the rarest parathyroid tumor. A diagnosis of PC is challenging because the clinical profile overlaps with that of benign counterpart. Surgery is the mainstay treatment. CDC73 mutations have been detected in up to 80% of sporadic PCs. Ectopic production of parathyroid hormone (PTH) by malignant nonparathyroid tumors is a rare condition accounting for less than 1% of hypercalcemia of malignancy. PTH secretion can be considered an aberration in the tissue specificity of gene expression and may involve heterogeneous molecular mechanisms.

Radiation Treatment for Inoperable Local Relapse of Parathyroid Carcinoma With Symptomatic Hypercalcemia: A Case Report

BACKGROUND

Parathyroid carcinoma (PC) is an extremely rare malignancy, characterized by slow progression, frequent recurrences and difficult-to-control hypercalcemia which is typically the main contributor to the morbidity and mortality of these patients. Patients often undergo repeated surgical resections, whether or not in combination with adjuvant radiation treatment. The role of radiation therapy within the symptomatic treatment of PC currently remains unclear.

CASE DESCRIPTION

We describe a 30-year-old male patient with an inoperable local relapse of PC and secondary symptomatic hypercalcemia, maximally pharmacologically treated. After a local radiation treatment to a total dose of 70 Gray in 35 fractions serum calcium and parathyroid hormone (PTH) levels decreased, accompanied by improvement of the severe gastro-intestinal disturbances.

CONCLUSION

For patients with inoperable symptomatic PC despite maximal medical treatment who are in a good overall condition, radiation treatment can be considered in well-defined cases to decrease symptoms and improve quality of life.

Local resection versus radical surgery for parathyroid carcinoma: A National Cancer Database analysis

INTRODUCTION

Parathyroid carcinoma (PC) is rare and often diagnosed incidentally after local resection (LR) for other indications. Although recommended treatment has traditionally been radical surgery (RS), more recent guidelines suggest that LR alone may be adequate. We sought to further investigate outcomes of RS versus LR for localized PC.

MATERIALS AND METHODS

PC patients from 2004 to 2015 with localized disease were identified from the National Cancer Database, then stratified by surgical therapy: LR or RS. Demographic and clinicopathologic data were compared. Cox proportional hazard models were constructed to estimate associations of variables with overall survival (OS). OS was estimated from time of diagnosis using Kaplan-Meier curves.

RESULTS

A total of 555 patients were included (LR = 522, RS = 33). The groups were comparable aside from LR patients having higher rates of unknown nodal status (66.9% versus 39.4%; p = 0.003). By multivariable analysis, RS did not have a significant association with OS (hazard ratio (HR) = 0.43, 95% confidence interval (95%CI) = 0.10, 1.83; p = 0.255), nor did positive nodal status (HR = 0.66, 95%CI = 0.09, 5.03; p = 0.692) and unknown nodal status (HR = 1.30, 95%CI = 0.78, 2.17; p = 0.311). There was no difference in OS between the LR and RS groups, with median survival not reached by either group at 10 years (median follow-up = 60.4 months; p = 0.20).

CONCLUSIONS

There was no difference in OS between LR and RS for localized PC. RS and nodal status may not impact survival as previously identified, and LR should remain a valid initial surgical approach. Future higher-powered studies are necessary to assess the effects of surgical approaches on morbidity and oncologic outcomes.

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).

Management and Outcome of Parathyroid Carcinoma-Induced Primary Hyperparathyroidism: A Single-Centre Experience

BACKGROUND

Parathyroid carcinoma (PC) is the rarest endocrine cancer and an infrequent cause of primary hyperparathyroidism (PHPT), responsible for less than 1% of cases. Due to its rarity, treatment is challenging.

METHODS

A retrospective cohort study on 462 patients referred for parathyroidectomy to Thyroid and Parathyroid Unit at Santi Paolo e Carlo Hospital, Milan, Italy, from 2011 to 2021. We identified and individually described the patients affected with PC. Then, we split all patients treated for PHPT into four groups based on the cause: PC, adenoma, atypical adenoma, and hyperplasia. Patients' demographics, preoperative evaluation results, intraoperative findings, and outcomes for the PC group were compared with groups of PHPT due to benign causes.

RESULTS

Eight cases of PC were identified, five males and three females. Seven cases presented with symptoms of hypercalcemia and one with a neck mass. Five underwent en bloc resections and three local excisions. Histopathological features showed capsular invasion in four patients, capsular and soft tissue invasion in three patients, and vascular invasion in one case. No patients had distant metastasis. One patient was classed as high risk based on the Schulte classification system. All patients treated for PC were alive and disease-free at a mean follow-up of 38.4 months. When compared with other PHPT patients, PC patients were more frequently male and had higher preoperative blood calcium and PTH and lower phosphate levels, larger and heavier parathyroids excised, lower postoperative calcium, and a higher rate of postoperative hypoparathyroidism.

CONCLUSION

Our study highlights some aspects valuable to suspect PC and differentiate PHPT-PC from benign causes of PHPT preoperatively. Preoperative suspicion of malignancy is essential to guarantee the best course of treatment for patients. Although limited for size and follow-up, the excellent outcome of our series seems to support the value of both surgery extension and risk class according to the Schulte classification as possible prognostic factors for recurrence.

Distinguishing Parathyromatosis, Atypical Parathyroid Adenomas, and Parathyroid Carcinomas Utilizing Histologic and Clinical Features

Parathyromatosis is displaced parathyroid tissue in the neck and mediastinum related to prior surgery. Parathyromatosis can be difficult to distinguish from atypical adenoma and parathyroid carcinoma. The aim of this study is to evaluate clinical and morphologic features that may differentiate parathyromatosis, atypical adenoma, and parathyroid carcinoma. Cases of parathyromatosis, atypical adenoma, and parathyroid carcinoma were identified. Index cases were reviewed by consensus for histologic features, including stromal, cytologic/architectural, and invasive features. Ki67 was performed on index cases and scored using the Adsay method. Clinical information was gathered from the electronic medical record. 4 parathyromatosis, 17 atypical adenoma, and 6 parathyroid carcinoma were included. Parathyroid carcinomas were more likely to display coarse chromatin with nucleoli (P = 0.04), infiltrative invasion (P < 0.01), and metastasis (P < 0.01). Only parathyromatosis showed circumscribed invasion. Infiltrative invasion was more common in cases with progression (P = 0.046) and metastasis (P < 0.001). Necrosis and perineural invasion were only present in cases with progression and were more frequent in cases with metastasis (P = 0.079 and P = 0.19, respectively). There were no differences in presence of a fibrous capsule, capsular invasion, intralesional fibrous bands, random endocrine atypia, solid growth, Ki67 index, gland size/weight, serum PTH/calcium levels, and locoregional recurrence rates. There is overlap in the histologic features in parathyromatosis, atypical adenoma, and parathyroid carcinoma. While perineural, vascular, and infiltrative soft tissue invasion should remain diagnostic of malignancy, other atypical features such as solid growth, coarse chromatin with nucleoli, and necrosis should raise concern for recurrence and/or metastasis, and can be present in parathyroid lesions with and without recurrence.

[The clinical practice guidelines for primary hyperparathyroidism, short version]

Primary hyperparathyroidism (PHPT) is an endocrine disorder of parathyroid glands characterized by excessive secretion of parathyroid hormone (PTH) with an upper normal or elevated blood calcium level. Classical PHPT refers to a symptomatic, multi-system disorder, wich can lead to a significant decrease in the quality of life, disability of patients, and even an increased risk of premature death. Hypercalcemia and the catabolic effect of PTH on various cells are considered as the main pathogenetic mechanisms of the PHPT associated complications. In the last two decades, there has been an increase in the incidence of PHPT, mainly due to the mild forms of the disease, primarily due to the routine calcium screening in North America, Western Europe and, Asia. High prevalence of the disease, as well as the variety of clinical manifestations, cause the attention of different specialists - physicians, rheumatologists, urologists, nephrologists, cardiologists and other doctors. This review cover the main issues of Russian guidelines for the management of PHPT, approved in 2020, including laboratory and instrumental methods, differential diagnosis, surgical and conservative approach, short-term and long-term follow-up. This guidelines also include the recommendations for special groups of patients with hereditary forms of PHPT, parathyroid carcinoma, PHPT during pregnancy.

Surgical Disparities of Parathyroid Carcinoma: Long-Term Outcomes and Deep Excavation Based on a Large Database

Purpose

Parathyroid carcinoma (PC) is an uncommon endocrine disease, and surgery is considered the only potential cure. PC does not have a mature staging system because of the small number of PC patients. Our aim is to further investigate the prognostic factors associated with PC and explore the optimal extent of resection for PC patients.

Methods

Univariate and multivariate Cox regression analyses were conducted to explore the influence of relevant factors on cancer-specific survival (CSS) and overall survival (OS). Survival curves were generated using the Kaplan–Meier method and analyzed using the log-rank test. The mortality rates per 1,000 person-years were calculated to evaluate patients' follow-up data. We also performed subgroup analysis based on the extent of resection.

Results

The extent of resection was related to both CSS and OS, whereas race and extent of disease had a significant positive correlation with OS (all P < 0.05). Patients who underwent parathyroidectomy had remarkably better CSS and OS than patients who did not undergo definitive treatment.

Conclusion

The extent of resection is related to CSS and OS in patients with PC. No significant difference in prognosis was observed between patients who underwent parathyroidectomy and those who underwent en bloc resection, which may provide useful parameters for the treatment of PC.

Intrathyroidal parathyroid carcinoma: a case report and literature review

Parathyroid carcinoma is an uncommon endocrine malignancy comprising 0.5%–2% of patients with primary hyperparathyroidism. The probability of an intrathyroidal location is low (0.2%) and make preoperative suspicion and diagnosis challenging. Less than 20 cases of intrathyroidal parathyroid carcinoma have been reported. We introduce a case of intrathyroidal parathyroid carcinoma mimicking a suspicious thyroid nodule, and review the literature, with a focus on the role of adjuvant radiotherapy.

Synchronous intrathyroidal parathyroid carcinoma and thyroid carcinoma: case report and review of the literature

BACKGROUND

Parathyroid carcinoma is a rare endocrine malignancy, rarer when synchronous with a non medullary well differentiated thyroid carcinoma. Parathyroid carcinoma accounts of 0.005% of all malignant tumors and it is responsible for less than 1% of primary hyperparathyroidism. The intrathyroidal localization of a parathyroid gland is not frequent with a reported prevalence of 0.2%. Carcinoma of parathyroids with intrathyroidal localization represents an even rarer finding, reported in only 16 cases described in literature. The rare constellation of synchronous parathyroid and thyroid carcinomas has prompted us to report our experience and perform literature review.

CASE PRESENTATION

We herein report a case of a 63-years-old man with multinodular goiter and biochemical diagnosis of hyperparathyroidism. Total thyroidectomy with radio-guide technique using gamma probe after intraoperative sesta-MIBI administration and intraoperative PTH level was performed. The high radiation levels in the posterior thyroid lobe discovered an intrathyroidal parathyroid. Microscopic examination revealed a parathyroid main cell carcinoma at the posterior thyroidal left basal lobe, a classic papillary carcinoma at the same lobe and follicular variant of papillary carcinoma at the thyroidal right lobe. To the best of our knowledge, this is the first case documenting a synchronous multicentric non medullary thyroid carcinomas and intrathyroidal parathyroid carcinoma.

CONCLUSIONS

Our experience was reported and literature review underlining challenging difficulties in diagnostic workup and surgical management was carried out.

Epidemiology and prognosis of parathyroid carcinoma: real-world data using nationwide cohort

PURPOSE

Parathyroid carcinoma (PC) is an exceedingly rare endocrine malignancy with a poor prognosis. Due to the rarity, the natural course and prognostic factors of the disease are yet unclear. Therefore, we aimed to identify the incidence, prognosis, and prognostic factors of PC in the nationwide cohort study.

METHODS

The study is a nationwide study using the National Health Insurance Services database in Korea from 2002 to 2017. PC was defined as patients with ICD-10 code of PC and a procedural code for parathyroidectomy.

RESULTS

From 2002 to 2017, 255 patients were diagnosed with PC whose mean age was 53.2 years, and 155 (60.2%) were women. The crude and age-standardized incidence were 10.2 and 6.6/10,000,000 person-year in 2016, rising from 4.1 and 3.8/10,000,000 person-year in 2003 (p < 0.001), respectively. The 5- and 10-year survival rates were 86.5 and 72.9%, respectively. In survival analysis, age over 50 years, thyroidectomy at the initial surgery, and reoperation had increased risk of mortality with HRs of 4.83 (95% CI 1.47-15.90), and 4.21 (95% CI 1.60-11.08), and 1.05 (95% CI 1.02-1.08) in multivariate analysis, respectively.

CONCLUSION

Incidence of PC has been rising over time, similar to the trends in Western countries. The prognostic factors for mortality were old age, parathyroidectomy alone, and recurrence, emphasizing the importance of preoperative suspicion of the disease. The study is clinically meaningful in the first Asian nationwide study to reveal the natural course of PC.

Selected Topics in the Pathology of the Thyroid and Parathyroid Glands in Children and Adolescents

The goals of this chapter in keeping with the overall general themes of this special edition will be (1) to highlight aspects of development of the thyroid and parathyroid glands with particular focus on the role and contribution of the neural crest (or not) and how this may impact on the pathology that is seen, (2) to emphasize those lesions particularly more commonly arising in the pediatric population that actually generate specimens that the surgical pathologist would encounter, and (3) highlight more in depth specific lesions associated with heritable syndromes or specific gene mutations since the heritable syndromes tends to manifest in the pediatric age group. In this light, the other interesting areas of pediatric thyroid disease including medical thyroid diseases, congenital hypothyroidism, anatomic variants and aberrations of development that lead to structural anomalies will not be emphasized here.

A Woman with a 27-Year History of Hyperparathyroidism and Hypercalcemia Who Was Diagnosed with Low-Grade Parathyroid Carcinoma

BACKGROUND Parathyroid carcinoma (PC), accounting for 0.005% of all cancers, is responsible for less than 1% of all cases of primary hyperparathyroidism, and equally affects males and females, usually in 4th or 5th decades of life. PC can occur sporadically and can be associated with congenital genetic syndromes such as hyperparathyroidism-jaw tumor syndrome (HPT-JT), isolated familial hyperparathyroidism, or multiple endocrine neoplasia 1 and 2 syndromes. Surgery is the main treatment, with a limited role of radio- and chemotherapy, which allows 49-77% of patients to survive 10 years. In this work we report the case of a patient with parathyroid carcinoma, whose treatment required 13 surgeries over a period of 27 years, together with radiotherapy and pharmacological treatment. CASE REPORT A 51-year-old woman was first diagnosed with primary hyperparathyroidism in 1993 at the age of 23. From 1993 to present, she underwent 13 surgeries and 33 courses of radiotherapy due to recurrent lesions, which initially had a character of parathyroid adenomas, then parathyromatosis, and finally were diagnosed as parathyroid carcinoma. The patient also required and currently requires complex pharmacological treatment to control the calcemia and manage the complications of the primary disease. Supervision by the multidisciplinary professional medical team allows the patient to lead a normal life with good control of the disease. CONCLUSIONS Parathyroid carcinoma is a rare disease with a number of complications; however, obtaining satisfactory long-term survival with acceptable quality of life is achievable.

Parathyroid cancer: A systematic review of diagnostic biomarkers

INTRODUCTION

Parathyroid cancers are rare and difficult to distinguish from benign parathyroid tumours. Prediction of malignancy often relies on intraoperative assessment of invasion. Standard histology is also inadequate; especially in the absence of local invasion, lymph nodal disease and metastasis. The aim of this project was to systematically review published literature on potential bio-markers used for the diagnosis of parathyroid cancer.

METHODS

Pubmed, Web of Science and Medline databases were searched. Inclusion criteria included English language papers published after 1985 and reporting on biomarkers in human studies of parathyroid cancer and benign disease.

RESULTS

118 relevant papers were appraised; all were observational studies. At least 2 papers studied 8 serum, 4 urine and 27 tissue biomarkers on the diagnosis of parathyroid cancer. Of these, 5 serum and 13 tissue markers have been demonstrated in at least one study to be statistically different in benign and malignant disease. We present a synthesis of data for each biomarker and measures of diagnostic accuracy where possible.

CONCLUSIONS

Consideration should be given to the use of a panel of biomarkers to review patients with suspected parathyroid cancer. A profile including serum calcium and PTH levels and tissue expression of APC, Parafibromin, PGP9.5, Galectin 3 and Ki67 is proposed. Systematic Review Registration Number - CRD42019127833.

Seven cases of parathyroid carcinoma and review of the literature

Parathyroid cancer is a rare malignancy and an uncommon cause of hyperparathyroidism. In the present study, we present seven cases of parathyroid carcinoma. The female ratio was 5/7 (71.4%). Median age at diagnosis was 47 years, and median follow-up duration was 60 months (IQR 29-75). Mean calcium level at diagnosis was 12.7 mg/dL (range, 11.3-13.9), and mean parathormone level was 1115 ng/L (IQR 287-1470). Two patients (28.5%) had a palpable neck mass. Coexisting brown tumor was present in three patients (42.8%), and nephrolithiasis was found in one patient (14.2). Average tumor size was 29 mm (IQR 28-40). Capsular and vascular invasion were detected in six patients (85.7%), intrathyroidal spread was observed in two patients (28.5%), and soft tissue invasion was seen in three patients (42.8%). Parathyroid adenoma was present in one patient and parathyroid gland hyperplasia in another patient. Adjuvant radiotherapy was given to four patients (57.1%). There was no metastatic disease or death. At the last visit, two patients had increased parathormone levels and no additional focus could be detected in either. Patients with markedly elevated parathormone and calcium levels and a palpable larger mass on the neck should be evaluated for parathyroid cancer. En bloc resection is the mainstay treatment. Despite contradictory results, adjuvant radiotherapy to the neck may help to reduce the risk of local recurrence in patients with microscopic residual parathyroid carcinoma.

Tumor Volume Can Be Used as a Parameter Indicating the Severity of Disease in Parathyroid Cancer

OBJECTIVE

To determine whether tumor volume and tumor size are related to disease severity in parathyroid cancer (PC).

METHODS

Patients treated for PC at our institution were retrospectively identified. Data were collected about clinical and pathologic characteristics, laboratory parameters, tumor volume, recurrence, metastasis, and mortality. Correlation analysis was applied to laboratory parameters, tumor volume, and tumor size in PC patients.

RESULTS

The study included 20 patients diagnosed with PC at our center. The median follow-up was 33 months. Serum calcium (median, 12.5 mg/dL), serum parathormone (PTH) (median, 743 pg/mL), and serum alkaline phosphatase (ALP) (median, 298 U/L) levels were found to be increased, and 25-hydroxyvitamin D (25[0H)D) (median, 12.3 ng/mL) and serum phosphorus (median, 2.1 mg/dL) levels were decreased. Magnesium level was within normal limits (median, 1.9 mg/dL). The median tumor volume was 5.7 mL and median tumor size was 2.5 cm. Significant positive correlations were found between tumor volume and calcium, ALP, and PTH levels. A significant negative correlation was found between tumor volume and 25(OH)D level. There were no significant correlations between tumor size and calcium, ALP, PTH, and 25(OH)D.

CONCLUSION

These results found that the tumor volume affected PTH, calcium, ALP, and 25(OH)D levels. The morbidity and mortality associated with PC were usually associated with PTH secretion and hypercalcemia. Therefore, tumor volume may be a more effective parameter than tumor size when evaluating the severity of disease.