Parathyroid cancer: biology and management

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.

Imaging Recommendations for Diagnosis and Management of Primary Parathyroid Pathologies: A Comprehensive Review

Parathyroid pathologies are suspected based on the biochemical alterations and clinical manifestations, and the predominant roles of imaging in primary hyperparathyroidism are localisation of tumour within parathyroid glands, surgical planning, and to look for any ectopic parathyroid tissue in the setting of recurrent disease. This article provides a comprehensive review of embryology and anatomical variations of parathyroid glands and their clinical relevance, surgical anatomy of parathyroid glands, differentiation between multiglandular parathyroid disease, solitary adenoma, atypical parathyroid tumour, and parathyroid carcinoma. The roles, advantages and limitations of ultrasound, four-dimensional computed tomography (4DCT), radiolabelled technetium-99 (99mTc) sestamibi or dual tracer 99mTc pertechnetate and 99mTc-sestamibi with or without single photon emission computed tomography (SPECT) or SPECT/CT, dynamic enhanced magnetic resonance imaging (4DMRI), and fluoro-choline positron emission tomography (18F-FCH PET) or [11C] Methionine (11C -MET) PET in the management of parathyroid lesions have been extensively discussed in this article. The role of fluorodeoxyglucose PET (FDG-PET) has also been elucidated in this article. Management guidelines for parathyroid carcinoma proposed by the American Society of Clinical Oncology (ASCO) have also been described. An algorithm for management of parathyroid lesions has been provided at the end to serve as a quick reference guide for radiologists, clinicians and surgeons.

Parathyroid carcinoma: Imaging features of initial presentation and recurrence. A single center experience

BACKGROUND AND PURPOSE

Parathyroid carcinoma is the rarest endocrine neoplasm with very few published data discussing its imaging appearance with primary focus on ultrasound imaging features. We present our 23 years institutional experience to highlight multimodality imaging evaluation at presentation and at recurrence.

MATERIAL AND METHODS

Retrospective chart review of clinical and pathological diagnosis of parathyroid carcinoma patients presented for initial or recurrent disease management at M.D. Anderson Cancer Center between the period of January 2000 and February 2023 was performed. Imaging findings on US, CT, PET/CT, and technetium-99m sestamibi were analyzed for initial and local recurrent parathyroid carcinoma. We further assess patterns of distant recurrence and its location.

RESULTS

Twenty three patients with pathological and clinical diagnosis of initial (14 patients) or recurrent parathyroid carcinoma (14 patients) were included in this study. US findings of parathyroid carcinoma were larger lesions, increased/irregular vascularity, and non-circumscribed margins. Multiphasic CT findings of parathyroid carcinoma included an arterially enhancing lesion that is hypoenhancing relative to the thyroid and demonstrates no washout on delayed imaging. Highly suggestive findings for recurrent disease included a hypoechoic solid nodule (91.67%) with increased vascularity on ultrasound (81.8%) with corresponding enhancement on CT.

CONCLUSION

Parathyroid carcinoma is a rare malignancy often diagnosed after surgical resection. We provided CT and US imaging features that are helpful in suggesting the diagnosis of parathyroid carcinoma and detection of early local recurrence.

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.

Innate differences in the molecular signature of normal inferior & superior human parathyroid glands: potential implications for parathyroid adenoma

Primary hyperparathyroidism is a common endocrine disorder. Interestingly, the majority (75%) of parathyroid tumors are localized to the inferior parathyroid glands. To date, the reason for this natural bias has not been investigated. We assessed the global gene expression profile of superior and inferior glands obtained from forensic autopsies. The genes with significant differential expression between superior and inferior parathyroids were further assessed by RT-PCR in 19 pairs. As an iterative approach, additional genes with an established role in parathyroid disorders, i.e., CASR, MAFB, PAX9, TBCE, TBX1, VDR, MEN1, CCND1, and CDC73 were also evaluated by RT-PCR in all 19 pairs of superior and inferior parathyroid glands. Seven homeobox genes, namely HOXA4, HOXA5, HOXBAS3, HOXB4, HOXB6, HOXB9, IRX1, and one encoding for ALDH1A2 showed a lower expression in the inferior parathyroid glands than in the superior. Conversely, SLC6A1 showed a higher expression in the inferior glands. Of the nine genes with significant differential mRNA expression among superior and inferior glands HOXB9, HOXB4 and IRX1 could be detected by western blotting/mass spectrometry. The study is the first to show the differential expression of nine genes HOXA4, HOXA5, HOXBAS3, HOXB4, HOXB6, HOXB9, IRX1, ALDH1A2, and SLC6A1 in inferior versus the superior parathyroid glands. This could have potential implications for the preferential localization of parathyroid tumors to the inferior parathyroid glands as observed in patients with primary hyperparathyroidism.

Secondary Mediastinal Bleeding Caused by Parathyroid Adenocarcinoma: A Case Report

Introduction

The clinical picture of parathyroid tumors is mainly related to hypercalcemia such as kidney stones and bone and muscle pain. However, spontaneous cervical hemorrhage due to parathyroidoma bleeding is rare with clinical manifestations of the painful swelling and bruising of the neck accompanied by dysphagia and dyspnea.

Case presentation

We report a case of a 71-year-old female patient who presented with acute cervical swelling and extensive bleeding spreading from the neck to the abdomen and 2 flanks. Investigation of patients revealed increased parathyroid hormone levels and hypercalcemia. The neck ultrasound showed the thyroid nodules in 2 lobes, and goiter plongeant on the right. Computed tomography scan images showed a hematoma spreading from the right side of the neck to the mediastinum.

Result

The patient required emergency surgery due to dyspnea and hemodynamic instability. The preoperative diagnosis was cervical bleeding with the likely cause being thyroid nodule rupture. However, during the surgery, the bleeding source was determined to be the right parathyroid tumor located deeply below the superior mediastinum. The patient's histopathological result of the tumor is parathyroid adenocarcinoma.

Conclusion

From our experience, the hemorrhage from parathyroid tumor should be considered as a cause of acute neck bleeding when no history of trauma or surgery is identified. Post-surgery histopathological analyses of the tumor are very important to detect parathyroid adenocarcinoma.

Investigating the risk of metabolic and cardiovascular comorbidities among patients with parathyroid cancer: a nationwide representative cohort study in Taiwan

BACKGROUND

This study aimed to determine whether primary parathyroid cancer patients were associated with increased metabolic and cardiovascular comorbidities in comparison to the general population.

METHODS

We used the National Taiwan Cancer Registry Database to construct a cohort of patients with parathyroid cancer from January 1, 2004, to December 31, 2019. We compared the incidence of hypertension, diabetes mellitus, hyperlipidemia, atrial fibrillation, coronary heart disease, and heart failure with the general population matched based on a propensity score in a one-to-five fashion.

RESULTS

A total of 72 parathyroid cancer patients and 360 matched general population (mean age: 55 years; 59% women) were included, with different exclusive numbers for each metabolic and cardiovascular comorbidity cohort. The number of cases based on a total of 2347.7 person-years of observation included 53 deaths, 29 hypertension, 9 diabetes, 13 hyperlipidemia, 10 atrial fibrillation, 18 coronary artery disease, and 13 heart failure. According to multivariate analysis, parathyroid cancer remained significantly associated with diabetes [hazard ratio (HR): 9.28; 95% confidence interval (CI): 1.72-50.07], hyperlipidemia (HR: 5.86; 95% CI: 1.61-21.31), and heart failure (HR: 4.46; 95% CI: 1.18-16.84). Sub-distribution of competing mortality events and subgroup analysis showed robust evidence of metabolic and cardiovascular comorbidities. This national cohort study demonstrated that adult parathyroid cancer patients had a significantly higher incidence of diabetes mellitus, hyperlipidemia, and heart failure than the general population.

CONCLUSIONS

An increased risk of metabolic and cardiac comorbidities among parathyroid cancer patients required great caution.

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.

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.

Patterns and Predictors of Cervical Lymph Node Metastasis in Parathyroid Carcinoma

Simple Summary

Parathyroid carcinoma (PC) is a rare endocrine malignancy with poor outcomes. Surgery remains the mainstay of PC treatment. However, due to the rarity of this malignancy, the optimal extent of PC surgery remains inconclusive, including whether to perform central lymph node dissection (LND). In the present study, we reported the patterns and predictors of cervical lymph node metastasis in PC based on a cohort of 68 PC patients. The results showed that the percentage of cervical lymph node metastasis in PC was 19.4% at initial surgery and 25.0% including reoperations for recurrencies. High-risk Schulte staging and CDC73 abnormalities were identified as risk factors for cervical lymph node metastasis. Central LND should be considered during remedial surgeries performed after previous local resection of PC for patients with high risk factors.

Abstract

Background: Parathyroid carcinoma (PC) is a rare endocrine malignancy with poor outcomes. Over 60% of PC patients experience repeated disease recurrence or metastasis. The significance of cervical lymph node dissection (LND) for PC remains inconclusive. Methods: PC patients diagnosed at Peking Union Medical College Hospital between 1992 and 2021 were reviewed retrospectively. Clinical data, initial tumor histological staging, parafibromin histochemical staining results, Ki67 index, CDC73 gene mutation status and outcome information were collected systemically. The risk factors for recurrence and lymph node or distant metastasis were explored. Results: Sixty-eight PC patients receiving LND were enrolled. Cervical lymph node metastasis was identified in 19.4% of patients at initial surgery and 25.0% of patients including reoperations for recurrences. The independent risk factor for PC recurrence was a Ki67 index ≥ 5% (HR4.41, 95% confidence interval (CI)1.30–14.95, p = 0.017). Distant metastasis was an independent prognostic factor for PC patient overall survival (HR 5.44, 95% CI 1.66–17.82, p = 0.005). High-risk Schulte staging (p = 0.021) and CDC73 abnormalities (p = 0.012) were risk factors for cervical lymph node metastasis. Conclusion: Most PCs were slow-growing, but lymph node metastasis was not rare. For patients planning to undergo remedial surgery after previous local resection of PC, central LND is suggested for tumors with high-risk Schulte staging or CDC73 abnormalities.

Renal hyperparathyroidism

The number of the patients with chronic kidney disease is now increasing in the world. The pathophysiology of renal hyperparathyroidism is closely associated with Klotho-FGF-endocrine axes, which must be solved definitively as early as possible. It was revealed that the expression of fgf23 is activated by calciprotein particles, which induces vascular ossification. And it is well known that phosphorus overload directly increases parathyroid hormone and hyperparathyroid bone disease develops in those subjects. On the other hand, low turnover bone disease is often recently. Both the patients with chronic kidney disease suffering from hyperparathyroid bone disease or low turnover bone disease are associated with increased fracture risk. Micropetrosis may be one of the causes of increased fracture risk in the subjects with low turnover bone disease. In this chapter, we now describe the diagnosis, pathophysiology and treatments of renal hyperparathyroidism.

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.

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.

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.

Primary hyperparathyroidism: Disease of diverse genetic, symptomatic, and biochemical phenotypes

Genetic, symptomatic, and biochemical heterogeneity of patients with primary hyperparathyroidism (PHPT) has become apparent in recent years. An in-depth, evidence-based review of the phenotypes of PHPT was conducted. This review was intended to provide the resulting information to surgeons who operate on patients with hyperparathyroidism. This review revealed that the once relatively clear distinction between familial and sporadic PHPT has become more challenging by the finding of various germline mutations in patients with seemingly sporadic PHPT. On the one hand, the genetic and clinical characteristics of some syndromes in which PHPT is an important component are now better understood. On the other hand, knowledge is emerging about novel syndromes, such as the rare multiple endocrine neoplasia type IV (MEN4), in which PHPT occurs frequently. It also revealed that, currently, the classical array of symptoms of PHPT is seen rarely upon initial presentation for evaluation. More common are nonspecific, nonclassical symptoms and signs of PHPT. In areas of the world where serum calcium levels are checked routinely, most patients today are "asymptomatic" and they are diagnosed after an incidental finding of hypercalcemia; however, some of them have subclinical involvement of bones and kidneys, which is demonstrated on radiographs, ultrasound, and modern imaging techniques. Last, the review points out that there are three distinct biochemical phenotypes of PHPT. The classical phenotype in which calcium and parathyroid hormone levels are both elevated, and other disease presentations in which the serum levels of calcium or intact parathyroid hormone are normal. Today several, distinct phenotypes of the disease can be identified, and they have implications in the diagnostic evaluation and treatment of patients, as well as possible screening of relatives.

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.

Intrathyroidal parathyroid carcinoma presenting as an asymptomatic hypercalcemia: a case report

INTRODUCTION

A 26-year-old female presented with severe hypercalcemia. She was asymptomatic. Blood analysis revealed high serum calcium (13 mg/dL = 3.25 mmol/L) and elevated intact parathyroid hormone (iPTH) levels (267.5 ng/L).

RESULTS

Ultrasonography showed a mixed solid-cystic nodule of 30 mm in the left thyroid lower lobe and a nodular lesion of 14 mm posterior of the thyroid upper pole suggestive for parathyroid adenoma. Sestamibi scan and magnetic resonance imaging (MRI) revealed hyperfunctioning parathyroid tissue posterior of the left thyroid upper lobe. During surgery, a 15 mm nodule in the usual location of the left superior parathyroid was resected. Intraoperative frozen section revealed normal parathyroid tissue and intraoperative PTH levels did not decrease. Left thyroidectomy was performed due to the large solid-cystic nodule. Intraoperative PTH levels normalized 10 min later. Pathologic examination revealed a 28 mm nodule in the lower thyroid pole compatible with a parathyroid carcinoma (PC). Due to positive margins, a completion thyroidectomy was performed. 5-year follow-up showed no recurrence.

CONCLUSIONS

PC is a rare entity comprising 0.5-2% of patients with primary hyperparathyroidism. Even more unusual is an intrathyroidal parathyroid gland (0.2%). Only a dozen cases of intrathyroidal PC have been reported. Our case is the second patient reported to be asymptomatic.

Severe symptomatic hyperparathyroidism-Is it carcinoma?-Case report and literature review

Parathyroid carcinoma is a rare disease, difficult to diagnose and associated with a poor prognosis. It must be suspected preoperatively, based on clinical and imaging grounds, in order to perform the best surgical option and avoid compromising patient's prognosis.

An Unusual Simultaneous Existence of Parathyroid Carcinoma and Papillary Thyroid Carcinoma: Case Report and Review of Literature

Synchronous parathyroid and papillary thyroid carcinoma are extremely rare. To our knowledge, only 15 cases have been reported in the last four decades. We describe a 50-year-old female without significant past medical or family history and no previous trauma presented with left heel pain that prompted her to seek medical attention. Physical examination was notable for a painless nodule at the left thyroid lobe. Laboratory evaluation showed a serum calcium level of 14.3 mg/dL (8.6–10.3 mg/dL) and intact parathyroid hormone level of 1160 pg/mL (12–88 pg/mL). 99Tc-sestamibi dual-phase with single-photon emission computed tomography fused images showed increased uptake at the left-sided inferior parathyroid gland. Neck ultrasound showed a 1.4 cm heterogeneous nodule in the middle-third of the left thyroid gland and a solitary 1.9 cm vascularized and hypoechoic oval nodule that was considered likely to represent a parathyroid adenoma. Due to its clinical context (severe hypercalcemia and very high levels of PTH), parathyroid carcinoma (PC) was suspected although imaging studies were not characteristic. The patient underwent en bloc resection of the parathyroid mass and left thyroid lobe and central neck compartment dissection. Pathology analysis revealed classical papillary thyroid carcinoma of classical subtype and parathyroid carcinoma. Immunohistochemical staining was positive for cyclidin D1 and negative for parafibromin. High clinical suspicion is required for parathyroid carcinoma diagnosis in the presence of very high level of parathyroid hormone, marked hypercalcemia, and the existence of any thyroid nodule should be approached and the coexistence of other carcinomas should be considered.

Contemporary Evaluation and Management of Parathyroid Carcinoma

Parathyroid carcinoma is a rare malignancy, representing 0.005% of all cancers and 0.5%-1% of all parathyroid disorders. Parathyroid carcinoma occurs equally in males and females, as opposed to primary hyperparathyroidism, which has a female predominance. Patients with parathyroid carcinoma present with symptoms of hypercalcemia, similar to those with benign primary hyperparathyroidism. Parathyroid carcinoma should be suspected when calcium or parathyroid hormone levels are high. Because of the difficulty of discerning parathyroid carcinoma from adenoma preoperatively, the diagnosis of carcinoma is often made only after parathyroidectomy. The goals of surgery are resection with negative margins because surgery represents the only opportunity for cure. Adjuvant therapy with chemotherapy or external beam radiation has not been proven to affect disease-free or overall survival for these patients. Recurrence is common, with reoperation recommended for resectable recurrent disease. Palliation with calcimimetic pharmacotherapy can aid with management of symptomatic hypercalcemia in recurrent or persistent disease after parathyroidectomy. Ultimately, patients succumb to sequelae of hypercalcemia rather than tumor burden.

Severe Primary Hyperparathyroidism Caused by Parathyroid Carcinoma in a 13-Year-Old Child; Novel Findings From HRpQCT

Primary hyperparathyroidism is a condition that occurs infrequently in children. Parathyroid carcinoma, as the underlying cause of hyperparathyroidism in this age group, is extraordinarily rare, with only a few cases reported in the literature. We present a 13-year-old boy with musculoskeletal pain who was found to have brown tumors from primary hyperparathyroidism caused by parafibromin-immunodeficient parathyroid carcinoma. Our patient had no clinical, biochemical, or radiographic evidence of pituitary adenomas, pancreatic tumors, thyroid tumors, pheochromocytoma, jaw tumors, renal abnormalities, or testicular lesions. Germline testing for AP2S1, CASR, CDC73/HRPT2, CDKN1B, GNA11, MEN1, PTH1R, RET, and the GCM2 gene showed no pathological variants, and a microarray of CDC73/HRPT2 did not reveal deletion or duplication. He was managed with i.v. fluids, calcitonin, pamidronate, and denosumab prior to surgery to stabilize hypercalcemia. After removal of a single parathyroid tumor, he developed severe hungry bone syndrome and required 3 weeks of continuous i.v. calcium infusion, in addition to oral calcium and activated vitamin D. Histopathological examination identified an angioinvasive parathyroid carcinoma with global loss of parafibromin (protein encoded by CDC73/HRPT2).HRpQCT and DXA studies were obtained prior to surgery and 18-months postsurgery. HRpQCT showed a resolution of osteolytic lesions combined with structural improvement of cortical porosity and an increase in both cortical thickness and density compared with levels prior to treatment. These findings highlight the added value of HRpQCT in primary hyperparathyroidism. In addition to our case, we have provided a review of the published cases of parathyroid cancer in children. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

[Ectopic tissue of the thyroid gland and the parathyroid glands]

Ectopic thyroid tissue results from developmental defects of the early stages of thyroid embryogenesis, in which the median thyroid anlage descends from the floor of the mouth to its final pre-tracheal position. The most common sites of ectopic thyroid tissue are accordingly in the area of the floor of the mouth and in the course of the thyroglossal duct. Rare localizations are intrathoracic (mediastinal, cardiac, pulmonary) and sub-diaphragmatic (including the adrenals, liver, gall bladder, and gastrointestinal tract). The most important differential diagnosis of ectopic thyroid is metastasis of differentiated thyroid carcinoma.By contrast, the term parathyroidectopy is not uniformly defined. Usually, the cervical-central localizations are referred to as "positional variants" (with the exception of the maxillary sinus and high parapharyngeal), whereas the cervical-lateral localizations (carotid sheath, vagus nerve) and those below the brachiocephalic and mediastinal positions (extraligamentary, aortopulmonary window, paravagal) and other rare localizations are classified as "ectopic parathyroid tissue". Parathyroidectomy is very common (in autopsy studies in 28 to 42.8% of all humans). In the context of primary hyperparathyroidism (pHPT), there is a prevalence of 6.3 to 16% of ectopic hyperfunctional parathyroid tissue (predominantly adenomas), which play an important role in the surgical treatment of pHPT.

Current concepts in parathyroid carcinoma: a single Centre experience

BACKGROUND

Parathyroid carcinoma is a rare neoplasm that may present sporadically or in the context of a genetic syndrome. Diagnosis and management are challenging due to the lack of clinical and pathological features that may reliably distinguish malignant from benign disease.

METHODS

From January 2013 to December 2017, from 358 consecutive patients affected by parathyroid diseases, 3 patients with parathyroid carcinoma were treated at our academic Department of General Surgery. We present our experience as illustrative of the different features of clinical presentation of parathyroid carcinoma and review its management considering the recent relevant literature.

RESULTS

Case 1: A 62-year-old man was hospitalized for left-sided palpable neck mass, hypercalcemia and elevated PTH. US-guided FNA was suspect for parathyroid carcinoma. A large cystic mass was excised in bloc with total thyroidectomy and central neck dissection. Genetic studies framed a pathologically confirmed parathyroid carcinoma within MEN1 syndrome. Case 2: A 48-year-old woman with hypothyroidism had total thyroidectomy performed for a suspect for right follicular thyroid lesion. Pathology revealed parathyroid carcinoma. Case 3: A 47 year-old man was admitted for hypercalcaemic crisis and renal failure in the context of PHPT. A lesion suggestive on US and MIBI scan for parathyroid adenoma in the right lower position was removed by mini-invasive approach. Pathology revealed parathyroid cancer and patient had completion hemythyroidectomy and central neck dissection.

CONCLUSION

Parathyroid cancer is a particularly rare endocrine malignancy, however it should be suspected in patients with primary hyperparathyroidism when severe hypercalcemia is associated to cervical mass, renal and skeletal disease. Parathyroid surgery remains the mainstay of treatment. Radical tumour resection and expedited treatment in a dedicated endocrine Center represent crucial prognostic factors.

Parathyroid Carcinoma: Analysis of Patient Characteristics and Outcomes in a Retrospective Review of Eight Cases seen in a Single Center

Eight cases of parathyroid carcinoma were identified (8 females; median age 45 years, range 28-72). Half of whom were diagnosed preoperatively. Hypercalcemic symptoms were seen in 87.5% of the patients and the main complication was nephrolithiasis. At presentation, the median calcium was 3.675 mmol/L, median phosphate of 0.68 mmol/L, median intact parathyroid hormone (iPTH) was 211 pmol/L. Five patients had regional nodes metastasis and 1 had distant metastasis to the lungs. Parathyroid gland invasion to adjacent structures was seen in 62.5% of cases while another 62.5% showed capsular or vascular infiltration on histology with median tumour size of 3.2 cm. Recurrent hypercalcemia occurred in 50% of the patients with median time of recurrence of 21 months. In this case series, we found that patients with severe hypercalcemia and high iPTH also exhibited a high index suspicion of PC.

Parathyroid carcinoma

Parathyroid carcinoma (PC) is a rare disease with an indolent behavior due to the low malignant potential. The etiology is unknown. Somatic mutations of CDC73 gene, the same gene involved in the hyperparathyroidism-jaw tumor syndrome, can be identified in up to 70% of patients with PC and in one-third of cases the mutations are germline. Therefore, in patients who carry germline CDC73 gene mutations, its finding permits to identify the carriers among relatives and sometimes to early detect a parathyroid lesion in such subjects. The diagnosis of PC is commonly made after surgery, however there are some clinical/biochemical features that should raise the suspicion of PC, namely markedly elevated serum calcium and PTH levels, a large parathyroid lesion with suspected ultrasonographic features of malignancy, the damages of kidney and bones. The best chance of cure is the complete surgical resection with the en-bloc excision at the first operation, however several recurrences are often observed during the follow-up. Since PC is an indolent tumor with long-lasting survival and the death is due to complications of untreatable hypercalcemia, multiple surgical interventions with debulking of tumoral tissues along with medical treatment for reducing hypercalcemia are often needed. Patients with PC should be followed up along their lifetime.

Previously unreported deletion of CDC73 involving exons 1-13 was detected in a patient with recurrent parathyroid carcinoma

Parathyroid carcinoma (PC) is a rare malignancy, presenting sporadically or as part of a genetic syndrome. Diagnosis of PC includes the histopathological diagnosis based on capsular, perineural, or vascular invasion or metastasis. High suspicion for malignancy includes hypercalcaemia greater than 14 mg/dL, extremely high serum parathyroid hormone (PTH) levels, as well as large masses. Given the rarity of PC, it is challenging to design clinical trials for newer therapy. Currently, complete initial surgical excision of the tumour in high-risk patients offers the best chance of cure and prolonged disease-free survival in PC. In the absence of definite data, non-surgical therapies such as radiation and chemotherapy are not routinely recommended. For early detection of recurrence; long-term clinical follow-up with interval measurements of serum calcium and PTH is recommended. Localising studies of PC are helpful. Early screening for CDC73 mutation and multidisciplinary treatment by an endocrine/ENT/surgical oncology team is recommended.

A rare case of symptomatic hyperparathyroidism in an elderly patient with dual pathology

Primary hyperparathyroidism secondary to true sporadic synchronous parathyroid cancer (PTCa) and adenoma (PTa) is rare. This is a case of an 80-year-old female admitted with symptomatic hypercalcaemia, raised serum calcium (Ca) of 3.39 mmol/L and raised parathyroid hormone (PTH) of 44.3 pmol/L. Ultrasonic evaluation of the neck revealed a mass posterior to the right thyroid lobe. Imaging of the left neck was unremarkable. Subsequent sesta-MIBI and single-photon emission computed tomography-computed tomography (SPECT-CT) scanning highlighted conspicuous activity over the right lower neck consistent with the neck ultrasound scan findings. Pre-operatively, PTa was suspected. Intra-operatively, malignancy was suspected due to infiltration of the parathyroid tumour into the thyroid. The right inferior parathyroid and right thyroid gland were resected. Histology confirmed PTCa. Despite surgical treatment, she was found to have persistently high Ca and PTH levels. Further investigation with a repeat sesta-MIBI and SPECT-CT suggested a left inferior parathyroid tumour. Excision of this mass revealed a PTa. Recovery was unremarkable and serum biochemistry returned to normal ranges.

Large deletion at the CDC73 gene locus and search for predictive markers of the presence of a CDC73 genetic lesion

The Hyperparathyroidism with Jaw-Tumours syndrome is caused by mutations of the CDC73 gene: it has been suggested that early onset of the disease and high Ca²⁺ levels may predict the presence of a CDC73 mutation. We searched for large deletions at the CDC73 locus in patients with: HPT-JT (nr 2), atypical adenoma (nr 7) or sporadic parathyroid carcinoma (nr 11) with a specific MLPA and qRT-PCR assays applied on DNA extracted from whole blood. A Medline search in database for all the papers reporting a CDC73 gene mutation, clinical/histological diagnosis, age at onset, Ca²⁺, PTH levels for familial/sporadic cases was conducted with the aim to possibly identify biochemical/clinical markers predictive, in first diagnosis, of the presence of a CDC73 gene mutation. A novel genomic deletion of the first 10 exons of the CDC73 gene was found in a 3-generation HPT-JT family, confirmed by SNP array analysis. A classification tree built on the published data, showed the highest probability of having a CDC73 mutation in subjects with age at the onset < 41.5 years (44/47 subjects, 93.6%, had the mutation). Whereas the lowest probability was found in subjects with age at the onset ≥ 41.5 years and Ca²⁺ levels <13.96 mg/dL (7/20 subjects, 35.0%, had the mutation, odds ratio = 27.1, p < 0.001). We report a novel large genomic CDC73 gene deletion identified in an Italian HPT-JT family. Age at onset < 41.5 ys and Ca²⁺ > 13.96 mg/dL are predictive for the presence of a CDC73 genetic lesion.

Parathyroid carcinoma: From a case report to a review of the literature

INTRODUCTION

Parathyroid carcinoma is a rare endocrine malignancy. The reported incidence is from 0.5 to 5% of primary hyperparathyroidism cases in various series. Consideration of parathyroid carcinoma in the differential diagnosis of hypercalcaemic disorders is important because the morbidity and mortality are substantial and the best prognosis is associated with early recognition and surgical resection.

PRESENTATION OF CASE

We report a case of parathyroid carcinoma occurring in a 60-year-old woman who presented to our institution with persistent hyperparathyroidism and hypercalcemia 3 years after being submitted to one gland parathyroidectomy in another hospital.

DISCUSSION AND CONCLUSION

A review of the related literature follows.

Clinical characteristics and treatment outcomes of parathyroid carcinoma: A retrospective review of 234 cases

Parathyroid carcinoma (PC) is one of the rarest known types of cancer and has a moderate prognosis, with estimated 5- and 10-year overall survival rates between 78–85% and between 49–70%, respectively. To raise awareness of this disease, and to optimize its diagnosis, clinical management and prognosis, the present study retrospectively reviewed 234 cases of PC. A total of 226 cases of PC, which were archived between 1984 and 2015 in the three major databases of the Chinese population, were retrieved and pooled with the 8 cases diagnosed and treated at the Department of Thyroid Surgery of The First Hospital of Jilin University (Changchun, China) between June 2008 and December 2015. The clinicopathological features, diagnosis, surgical procedures and outcomes of these cases of PC were investigated. The review revealed that misdiagnosis has been a considerable issue, with >80% of the patients misdiagnosed prior to surgery, and the accuracy of intraoperative diagnosis based on frozen sections was only 15.04%. The use of radical resection as first-line therapy significantly improved the disease-free survival by ~8 years (log-rank, 20.956; P<0.001); and, at relapse, reoperation prolonged patient survival by ~7 years (log-rank, 35.322; P<0.001). Consistently, a Cox proportional hazards analysis indicated that radical resection as a first-line therapy reduced the risk of postoperative recurrence (P=0.030), and that reoperation following recurrence significantly improved patient survival (P=0.030). The 5- and 10-year cumulative disease-specific survival rates of the cases of PC were 83 and 67%, respectively. Notably, an increased mortality rate was observed among males with PC compared with female patients with PC. In summary, in the past 32 years (1984–2015), the majority of patients with PC have been misdiagnosed. Performing radical resection as the first-line therapy significantly reduces recurrence and improves patient survival time; and, following relapse, subsequent surgery has also been demonstrated to be an effective approach.

Differentiation of parathyroid carcinoma and adenoma by preoperative ultrasonography

Background Parathyroid carcinomas (PTC) are very rare. There have been a few studies on the contribution of ultrasound (US) in the diagnosis of PTC compared with parathyroid adenomas (PTA). Purpose To identify the differences between US findings of PTC and PTA in patients with primary hyperparathyroidism (PHPT). Material and Methods We enrolled seven patients with PTC and 32 consecutive patients with PTA whose diagnoses were confirmed by surgery at our institution between March 1994 and June 2015. We retrospectively compared the US features of the two groups, as well as the demographic, clinical, and biochemical characteristics (age, gender, palpability, and serum ionized calcium and parathyroid hormone [PTH] levels). Results The patients with PTC and PTA did not exhibit significant differences in terms of mean age (59.0 years versus 51.1 years; P = 0.2063), sex distribution (male:female, 4:3 versus 1:3; P = 0.1716), mean PTH levels (2855.0 pg/mL versus 1821.5 pg/mL; P = 0.2067), and mean ionized calcium levels (1.7 mMol/L versus 1.5 mMol/L; P = 0.1585) except palpability ( P < 0.0001). On US images, the PTCs were significantly larger (3.5 cm versus 1.9 cm; P = 0.0133) and exhibited higher incidences of heterogeneous echotexture ( P = 0.0002), irregular shape ( P < 0.0001), non-circumscribed margin ( P < 0.0001), intra-nodular calcifications ( P = 0.014), and local invasion ( P = 0.0004) compared to the PTAs. Conclusion In preoperative patients with PHPT, PTCs are differentiated from PTAs by their palpability and significant US features: large size, heterogeneous echotexture, irregular shape, non-circumscribed margin, intra-nodular calcifications, and local invasion.

Hypercalcaemic encephalopathy due to metastatic parathyroid carcinoma

A 49-year-old man presented in the emergency department with altered sensorium and renal failure and was placed on a ventilator. Evaluation with MRI of the brain showed enhancing lesion in the occipital lobe. Biochemical tests revealed elevated calcium and parathyroid hormone (PTH) levels. Further evaluation revealed multiple lesions at both lobes of the lungs and nodular lesion in the right inferior pole of the thyroid. Diagnosis of metastatic parathyroid carcinoma was suspected. Patient was stabilised with bisphosphonates and haemodialysis and planned for surgery. Intraoperatively a hard lesion was found in the right inferior parathyroid infiltrating the surrounding structures. En bloc resection was done. General condition of the patient improved and he was weaned from the ventilator. Histopathology confirmed the diagnosis of parathyroid carcinoma. Postoperatively, there was persistent elevation of PTH in spite of a fall in calcium levels indicating functioning brain and pulmonary metastases. Due to extensive metastases, the patient was given palliative cinacalcet and was kept under follow-up.

A germline mutation of HRPT2/CDC73 (70 G>T) in an adolescent female with parathyroid carcinoma: first case report and a review of the literature

Parathyroid carcinoma is a rare cause of primary hyperparathyroidism amongst children, with only nine previously reported cases. The objective of the study was to present the first pediatric case with a germline CDC73 (formerly known as HRPT2) mutation, and to review the literature. A 14-year-old girl presented with pathologic slipped capital femoral epiphysis (SCFE). The patient was noted to have an elevated calcium level of 3.4 mmol/L (13.4 mg/dL), a parathyroid hormone (PTH) level of 1013 ng/L (1013 pg/mL), and a 3-cm palpable neck mass. Ultrasound and 99mTc-Sestamibi confirmed the suspicion of a parathyroid mass. Intraoperative findings and pathology confirmed the diagnosis of parathyroid carcinoma. Post-operative PTH decreased to 14 ng/L (14 pg/mL). Genetic testing showed a germline 70 G>T HRPT2/CDC73 mutation. This is the first case documenting a germline 70 G>T HRPT2/CDC73 gene mutation in a pediatric parathyroid carcinoma. Patients with sporadic parathyroid carcinoma may benefit from HRPT2/CDC73 gene mutation screening.

An unusual mediastinal parathyroid carcinoma coproducing PTH and PTHrP: A case report

Parathyroid carcinoma (PTCA) is a rare disease, and ectopic PTCA is particularly rare. Parathyroid hormone-related protein (PTHrP) expression in PTCA has not been previously described in the relevant literature to the best of our knowledge. The present study reports a unique case with a mediastinal parathyroid carcinoma producing parathyroid hormone (PTH) and PTHrP. A 53-year-old man presented with hyperparathyroidism symptoms, including fatigue, chest pain, dizziness, muscular soreness, polyuria, night sweats and renal stones. However, neck ultrasound revealed no significantly abnormal thyroid or parathyroid nodules. Tc99m methoxyisobutylisonitrile (Tc99m-MIBI) scintigraphy scanning indicated an ectopic mediastinal parathyroid adenoma. Histopathological examination revealed PTCA, and the tumor tissue was coproducing PTH and PTHrP. The patient underwent successful surgical operation. Serum calcium and PTH levels remained within normal ranges, and there was no tumor recurrence observed at a 3-year follow-up appointment. Although rare, ectopic parathyroid glands may lead to malignant disease. Clinical symptoms, biochemical tests, ultrasound and Tc99m-MIBI scintigraphy scanning may assist with the diagnosis of this disease. Hypersecretion of PTHrP and PTH contributed collaboratively to the pathogenesis of hypercalcemia due to PTCA. Complete surgical resection with microscopically negative margins is the recommended treatment for PTCA and offers the best chance of a cure.

Resection of a large ectopic parathyroid adenoma: A case report

INTRODUCTION

Parathyroid adenomas are the most common cause of primary hyperparathyroidism. However, cases of parathyroid adenomas greater than 4cm with osteitis fibrosa cystica are extremely rare. Herein, we report a case of resection of a large ectopic mediastinal parathyroid adenoma.

CASE PRESENTATIONS

A 46-year-old female with chief complaints of bone pain and gait disturbance was referred to our hospital. Physical examination revealed many mobile teeth in her oral cavity, distortion of the vertebral body, and bowlegs. Laboratory tests showed hypercalcemia, hypophosphatemia, and elevated serum levels of intact parathyroid hormone. Chest CT revealed a 42-mm well-defined, enhancing mass in front of the left-sided tracheal bifurcation. Her findings were diagnosed as primary hyperparathyroidism due to an ectopic mediastinal parathyroid tumor. We performed a median sternotomy and resected the tumor. The tumor was a solid, yellowish-brown mass measuring 42×42 mm. Pathologically, the tumor consisted mainly of chief cells with some oxyphil cells; there were no necrotic areas or nuclear atypia, and few mitotic figures. We diagnosed the tumor as an ectopic mediastinal parathyroid adenoma. Eight months after the resection, her serum calcium, phosphorus, and intact PTH levels were normal.

DISCUSSION AND CONCLUSIONS

Parathyroid adenomas and parathyroid carcinomas have disparate natural histories, but they can be difficult to differentiate on the basis of preoperative clinical characteristics. We believe that long-term follow-up of these cases is required because there have been few reports on the postoperative natural history of large parathyroid adenomas.

Prevalence of parathyroid carcinoma in 348 patients with multiple endocrine neoplasia type 1 - case report and review of the literature

OBJECTIVE

To report the prevalence of parathyroid carcinoma (PC) in patients with multiple endocrine neoplasia type 1 (MEN1) and review of the literature.

BACKGROUND

Primary hyperparathyroidism (PHP) is the most common manifestation of MEN1. The occurrence of PC in patients with MEN1 is rare and the literature regarding the clinical manifestations - including the prevalence of the disease - is scarce.

CONTEXT

Single tertiary care centre experience from 1977 to 2013.

DESIGN

Electronic search of the medical records to identify a cohort of patients with MEN1. Literature review based on current case reports.

PATIENTS

Single case of PC in a cohort of 348 patients with MEN1. Ten cases of PC in patients with MEN1 reported in the literature.

MEASUREMENT

Clinical features of PC in patients with MEN1.

RESULTS

The prevalence of PC in 348 patients with MEN1 was found to be 0·28% (95% CI, 0-1·4%). Based on the current published cases of PC in patients with MEN1, 54·5% were women, mean age at diagnosis was 48·3 years, and the serum PTH concentrations at least four times the upper limit of the reference range in 73% of the cases.

CONCLUSION

PC in patients with MEN 1 is rare with a prevalence of 0·28%, and the clinical features are similar to PC in patients without MEN1.

Parathyroid Cancer in the Pediatric Patient

CONTEXT

Parathyroid carcinoma is exceedingly rare in children. We describe a case of parathyroid cancer in a young female who was originally classified as benign and managed surgically. Upon her diagnosis with malignancy, concurrent with metastatic lung involvement, she was referred for medical and surgical palliation to control her symptomatic hypercalcemia. We briefly review published childhood cases, consider the challenges in differentiating malignant from benign hyperparathyroidism in this age group, and discuss the association of CDC73 mutations with parathyroid carcinoma.

CASE PRESENTATION

A 13-year-old African American girl with a history of parathyroid adenoma, diagnosed at 8 years of age with multiple recurrences, presented with hypercalcemia and elevated parathyroid hormone when her disease had been reclassified as malignant. Germline gene analysis revealed a heterozygous partial deletion of CDC73. The patient underwent palliative surgery for disease metastatic to her lungs. She continues with medical management of her hypercalcemia.

CONCLUSIONS

A case of pediatric parathyroid carcinoma associated with haploinsufficiency of CDC73 is discussed. We review all published cases of pediatric parathyroid carcinoma and offer diagnostic considerations for a parathyroid mass in a child.

Evaluation of malignant parathyroid tumours in two European cohorts of patients with sporadic primary hyperparathyroidism

Purpose

Parathyroid carcinoma (PC) is remarkable for its rare occurrence and challenging diagnostics. PC accounts for 0.1–5 % cases of primary hyperparathyroidism (PHPT). The differentiation from benign tumours is difficult even by morphological criteria. To address these issues, we assessed the PC frequency in two separate European PHPT cohorts and evaluated the demographic, clinical, morphological and molecular background.

Methods

A retrospective study was carried out, using continuously maintained database (2005–2014) of PHPT patients from two tertiary referral university hospitals in Europe. The demographic, clinical data and frequency of PC among surgically treated PHPT was detected. Immunohistochemistry (IHC) was performed to detect parafibromin, representing protein product of HRPT2 gene and proliferation marker Ki-67.

Results

Both PHPT cohorts were characterised by close mean age values (58.6 and 58.0 years) and female predominance. The frequency of PC differed significantly between the cohorts: 2.1 vs. 0.3 %; p = 0.004. PC was characterised by invariable complete loss of parafibromin contrasting with parathyroid adenomas. The proliferation fraction was similar in both PC cohorts (10.6 and 11.0 %). PC showed significantly higher proliferation fraction than typical parathyroid adenomas (1.6 %), atypical adenomas (1.6 %) or adenomas featuring focal loss of parafibromin (2.2 %).

Conclusions

PC frequency can range significantly between the two European cohorts. The differences can be attributable to selection bias of patients referred for surgery and are not caused by discordant definition of malignant parathyroid histology. Diffuse loss of parafibromin and increased proliferation fraction by Ki-67 are valuable adjuncts in PC diagnostics due to significant differences with various clinical and morphological subtypes of adenoma.

Non-functional parathyroid carcinoma: a case report and review of the literature

Non-functional parathyroid carcinoma is an exceedingly rare disease with 31 reported cases since 1909. Because of the scarce number of cases of non-functional parathyroid carcinoma, there are no evidence-based recommendations for its optimal treatment. Surgery, including en bloc resection of the carcinoma, ipsilateral thyroid lobe and isthmus together with a neck dissection only in case of lymph node involvement, is the main treatment for non-functioning parathyroid carcinoma. The patient usually has a poorer prognosis because of detection at advanced stages, the relative ineffectiveness of adjuvant treatment modalities and the lack of adequate parameters for clinical follow-up. In this report, we present a case of non-functional parathyroid carcinoma at our institution, and we review the previous literature to discuss the latest advances in the diagnosis and treatment of this rare disease.

Replication and Meta-Analysis of Common Gene Mutations in TTF1 and TTF2 with Papillary Thyroid Cancer

Papillary thyroid cancer (PTC), one of the most common malignant thyroid tumors, exits widely in the thyroid of adolescents. Thyroid transcription factor 1 (TTF1) and 2 (TTF2) were thyroid-specific transcription factors, and regulated expression of the thyroid-specific genes. Hence, the aim of the present study was to evaluate the correlation between gene variants of TTF1 and TTF2 and the risk of PTC in Chinese population.Two tagging single-nucleotide polymorphisms (tSNPs) on TTF1 and TTF2 were selected and genotyped by matrix-assisted laser desorption/ionization time-of-flight (MALDITOF) mass spectrometry in a hospital-based case-control study of 297 PTC patients and 594 healthy controls. Furthermore, a meta-analysis of the association between TTF1 and TTF2 and PTC risk was also performed.We found that the rs944289 on the TTF1 was significantly associated with increased PTC risk (TT vs CC, OR = 1.53, 95% CI = 1.05-2.24; CT + TT vs TT, OR = 1.34, 95% CI = 1.00-1.79; T vs C, OR = 1.27, 95% CI = 1.04-1.55). Similarly, the rs965513 on the TTF2 can also elevate the risk of PTC significantly (GA vs GG, OR = 1.67, 95% CI = 1.07-2.59; AA+GA vs AA, OR = 1.37, 95% CI = 1.09-1.82; A vs G, OR = 1.29, 95% CI = 1.05-1.59). Furthermore, results of stratified analysis revealed that the risk effects of rs944289 and rs965513 were more overpowering in the subgroups of patients with MNG, as well as subjects without metastasis. Results of meta-analysis from the previous study and our new data indicated that variants of rs944289 and rs965513 might be the genetic susceptible factors both in Asians and Caucasians.We get the conclusion that mutations of TTF1 and TTF2 are significantly associated with an increasing risk of PTC in Chinese. However, more detailed investigations and further large-scale studies on genetic functions to provide more conclusive and accurate evidence are required in the future.