Parathyroid carcinoma arising from parathyroid hyperplasia: autoinfarction following intravenous treatment with pamidronate

Values and other decisional factors regarding treatment of hypercalcaemia of malignancy: a systematic review protocol

INTRODUCTION

Hypercalcaemia of malignancy (HCM) is the second most common cause of hypercalcaemia and is associated with significant morbidity and mortality. Several treatment options are available including pharmacological therapy with bisphosphonates, denosumab, glucocorticoids and calcimimetics, as well as conventional therapy with hydration and possibly calcitonin. While guidelines have previously considered treatment effects, no guideline has yet considered a range of contextual factors impacting recommendations for the management. The aim of this study was to summarise the available evidence on important decisional factors for the development of guidelines for the treatment of HCM. These include patient's values and preferences, cost, acceptability, feasibility and equity.

METHODS AND ANALYSIS

This protocol is registered in PROSPERO (registration number: CRD42021264371). This is a systematic review of observational studies, case series, trials, reviews and qualitative studies involving treatment of adult patients with HCM. We will develop and execute two independent search strategies using five databases: PubMed, Medline (OVID), Embase.com, CINAHL (EBSCO) and Cochrane, and review their combined output. Two reviewers will screen titles and abstracts and full texts and will implement data abstraction from relevant studies independently and in duplicate. The outcomes of interest are the decisional factors that influence drug selection, with possible subgroup summaries by drug class or aetiology of HCM. We will present the data collected in a narrative and thematic approach.

ETHICS AND DISSEMINATION

Ethical approval is not applicable for our study, since we will only collect data from available literature. This systematic review will be submitted to a peer-reviewed journal when completed.

Two cases of spontaneous remission of primary hyperparathyroidism due to auto-infarction: different management and their outcomes

Spontaneous remission of primary hyperparathyroidism (PHPT) due to necrosis and haemorrhage of parathyroid adenoma, the so-called 'parathyroid auto-infarction' is a very rare, but previously described phenomenon. Patients usually undergo parathyroidectomy or remain under close clinical and biochemical surveillance. We report two cases of parathyroid auto-infarction diagnosed in the same tertiary centre; one managed surgically and the other conservatively up to the present time. Case #1 was a 51-year old man with PHPT (adjusted (adj.) calcium: 3.11 mmol/L (reference range (RR): 2.20-2.60 mmol/L), parathyroid hormone (PTH) 26.9 pmol/L (RR: 1.6-6.9 pmol/L) and urine calcium excretion consistent with PHPT) referred for parathyroidectomy. Repeat biochemistry 4 weeks later at the surgical clinic showed normal adj. calcium (2.43 mmol/L) and reduced PTH. Serial ultrasound imaging demonstrated reduction in size of the parathyroid lesion from 33 to 17 mm. Twenty months later, following recurrence of hypercalcaemia, he underwent neck exploration and resection of an enlarged right inferior parathyroid gland. Histology revealed increased fibrosis and haemosiderin deposits in the parathyroid lesion in keeping with auto-infarction. Case #2 was a 54-year-old lady admitted with severe hypercalcaemia (adj. calcium: 4.58 mmol/L, PTH 51.6 pmol/L (RR: 1.6-6.9 pmol/L)) and severe vitamin D deficiency. She was treated with intravenous fluids and pamidronate and 8 days later developed symptomatic hypocalcaemia (1.88 mmol/L) with dramatic decrease of PTH (17.6 pmol/L). MRI of the neck showed a 44 mm large cystic parathyroid lesion. To date, (18 months later), she has remained normocalcaemic. Learning points: Primary hyperparathyroidism (PHPT) is characterised by excess parathyroid hormone (PTH) secretion arising mostly from one or more autonomously functioning parathyroid adenomas (up to 85%), diffuse parathyroid hyperplasia (<15%) and in 1-2% of cases from parathyroid carcinoma. PHPT and hypercalcaemia of malignancy, account for the majority of clinical presentations of hypercalcaemia. Spontaneous remission of PHPT due to necrosis, haemorrhage and infarction of parathyroid adenoma, the so-called 'parathyroid auto-infarction', 'auto-parathyroidectomy' or 'parathyroid apoplexy' is a very rare in clinical practice but has been previously reported in the literature. In most cases, patients with parathyroid auto-infarction undergo parathyroidectomy. Those who are managed conservatively need to remain under close clinical and biochemical surveillance long-term as in most cases PHPT recurs, sometimes several years after auto-infarction.

Synchronous Sporadic Carcinoma and Primary Hyperplasia of the Parathyroid Glands: A Case Report and Review of the Literature

Parathyroid carcinoma is the least common endocrine malignancy. Although it has been noted to be associated with certain clinical factors, such as familial hyper-parathyroidism, its etiology remains unknown. In rare instances, particularly in patients with chronic renal failure, it has been proposed that parathyroid carcinoma can arise from malignant transformation of benign lesions. We present a case of synchronous malignant and primary hyperplastic parathyroid disease in a patient with normal renal function. A 46-year-old woman was seen with symptomatic refractory hypercalcemia. Investigations suggested a hyperactive parathyroid gland. Operative findings were of a low-grade parathyroid carcinoma in concurrence with diffuse hyperplasia of the remaining glands. To our knowledge this represents the fifth reported case. The possibility of malignant change in hyperplastic parathyroid tissue has implications for patient management and follow-up, particularly if tissue is left in situ to maintain hormonal function.

Management and surgical treatment of parathyroid crisis secondary to parathyroid tumors: report of four cases

Parathyroid crisis, also known as a parathyroid storm, is a rare and serious complication of primary hyperparathyroidism. Four cases are reported here in which patients presented to hospital with general complaints due to hypercalcemia secondary to hyperparathyroidism. Blood test results upon admission showed high levels of serum calcium and parathyroid hormone, and medical treatment initiated to lower the calcium level was ineffective. After relevant investigations, each patient underwent surgical exploration of the parathyroid glands, followed by excision of a pathological parathyroid tumor. There was a prompt decrease in parathyroid hormone level immediately after surgery. Histology reports revealed that patients had parathyroid adenoma. All patients recovered after surgery, with serum calcium levels restored back to normal and with resolution of all symptoms of hypercalcemia. This report illustrates how often this disease is initially misdiagnosed, and how prompt appropriate surgical treatment provides the best outcome for the patient.

Lymph node involvement and surgical approach in parathyroid cancer

BACKGROUND

The best surgical approach to parathyroid cancer is disputed. Recommendations vary and are built on incoherent evidence. High rates of recurrence and death require an in-depth review of underlying findings.

METHODS

This retrospective study includes 11 patients with parathyroid cancer who underwent surgery with central and/or lateral neck dissection by a single surgeon between 2005 and 2010. The diagnosis was based on histopathological criteria in all patients. Patterns of lymph node and soft tissue involvement of these and formerly reported patients were analysed based on full-text review of all published cases of parathyroid cancer.

RESULTS

In this series only 1 of 11 patients (9.1%) manifested lymph node metastasis. In the literature, lymph node metastases have been reported in only 6.5% of 972 published patients, or in 32.1% of the 196 in whom lymph node involvement was assessed by the authors. They were, with few exceptions, localised in the central compartment. Recurrence in soft tissue is more frequent than in locoregional lymph nodes.

CONCLUSION

Oncological en bloc clearance of the central compartment with meticulous removal of all possibly involved soft tissues, including a systematic central lymph node resection, may improve outcomes and should be included in the routine approach to the suspicious parathyroid lesion. There is no need for a prophylactic lateral neck dissection.

Clinical presentation, staging and long-term evolution of parathyroid cancer

BACKGROUND

Parathyroid cancer is rare and often fatal. This review provides an in-depth analysis of 330 clinical cases reported in detail. These data are used to inform a proposal for a hitherto lacking TNM staging system.

MATERIALS AND METHODS

All case reports or series with sufficient case details of parathyroid cancer were identified from PubMed, and data were analyzed using SPSS.

RESULTS

Of 330 patients, 117 (35%) died of disease and 207 (63%) experienced recurrence in a total of 2007 follow-up years and a mean length of follow-up of 6.1 years. Histopathology findings rather than biochemical or clinical features predict outcome. In univariate analysis, survival and recurrence rates are significantly influenced by gender (male relative risk [RR] 1.7, 95% confidence interval [95% CI] 1.0-2.7, P < .01), and presence of vascular invasion (RR 4.3, 95% CI 1.1-17.7, P < .01), or lymph node metastases (RR 6.2, 95 %CI 0.9-42.9, P < .001). Failure to perform oncological surgery carries a high risk for recurrence and death (local versus en bloc resection RR 2.0, CI 1.2-3.2, P < .01) as for redo surgery. Staging by a novel anatomy-based TNM system identifies significant outcome variation as to recurrence and death. Separation of patients into low and high risk identifies a 3.5-7.0 fold higher risk of recurrence and death (P < .01) for the high-risk group. Distant metastases predominantly target mediastinum and lung.

CONCLUSION

Understaging and undertreatment are shown to contribute to high recurrence rates and death toll. To improve outcome, en bloc resection including central lymph node dissection should be the minimal surgical approach in any patient with suspected parathyroid cancer.

Surveillance for early detection of aggressive parathyroid disease: carcinoma and atypical adenoma in familial isolated hyperparathyroidism associated with a germline HRPT2 mutation

Familial hyperparathyroid syndromes involving mutations of HRPT2 (also CDC73), a tumor suppressor, are important to identify because the relatively high incidence of parathyroid malignancy associated with such mutations warrants a specific surveillance strategy. However, there is a dearth of reports describing experience with surveillance and early detection informed by genetic insight into this disorder.

INTRODUCTION

Familial isolated hyperparathyroidism (FIHP) is a rare cause of parathyroid (PT) tumors without other neoplasms or endocrinopathies. Germline mutations in CASR, MEN1, and rarely, HRPT2 have been identified in kindreds with FIHP. HRPT2 mutations may be enriched in FIHP families with PT carcinoma, underscoring the importance of identifying causative mutations.

MATERIALS AND METHODS

A 13-year-old boy, whose father had died of PT carcinoma, developed primary hyperparathyroidism. A left superior PT mass was identified by ultrasonography and removed surgically. Aggressive histological features of the boy's tumor included fibrous trabeculae, mitoses, and microscopic capsular infiltration. Two years later, under close biochemical surveillance, primary hyperparathyroidism recurred 5 months after documentation of normocalcemia and normal parathyroid status. Ultrasound and MRI identified a newly enlarged right superior PT gland but indicated no recurrent disease in the left neck. Histologic features typical of a benign adenoma were evident after surgical extirpation of the gland.

RESULTS

Leukocyte DNA analysis revealed a frameshift mutation in exon 2 of HRPT2. The initial tumor manifested the expected germline HRPT2 mutation, plus a distinct somatic frameshift mutation, consistent with the Knudson "two hit" concept of biallelic inactivation of a classic tumor suppressor gene. Genetic screening of the patient's 7 asymptomatic and previously normocalcemic siblings revealed three with the same germline HRPT2 mutation. One of the siblings newly identified as mutation-positive was noted to be hypercalcemic at the time of the genetic screening. He was found to have a PT adenoma with aggressive features. Two of the five children of another mutation-positive sibling also carry the same HRPT2 mutation.

CONCLUSIONS

Despite the reported rarity of HRPT2 mutations in FIHP, a personal or family history of PT carcinoma in FIHP mandates serious consideration of germline HRPT2 mutation status. This information can be used in diagnostic and management considerations, leading to early detection and removal of potentially malignant parathyroid tumors.

Concurrent nonfunctioning parathyroid carcinoma and parathyroid adenoma

Parathyroid carcinoma is a rare etiology of primary hyperparathyroidism characterized by severe clinical symptoms of hypercalcemia and markedly elevated serum parathormone levels. Nonfunctioning parathyroid carcinoma is an inactive form of the disease. There are less than 30 reports of nonfunctioning parathyroid carcinoma in the English literature and the association with parathyroid adenoma has not been described. This report describes a patient with concurrent nonfunctioning parathyroid carcinoma and a functioning parathyroid adenoma.

Parathyroid carcinoma

Parathyroid carcinoma is an uncommon malignancy. It accounts for less than 1% of cases of primary hyperparathyroidism (HPT). It is manifested by severe hypercalcemia and up to 50% of patients will have concomitant kidney or bone disease. The etiology of parathyroid carcinoma is unknown, however, the recently discovered HRPT2 gene, a tumor suppressor gene encoding for the protein parafibromin, has been implicated in the pathogenesis. Identification of inactivating germ-line mutations in HRPT2 has significant implications for diagnosis and management. This article summarizes the genetic aspects of parathyroid carcinoma, reviews its clinical manifestations, and outlines the principles of surgical therapy, the indications for adjuvant therapy, and the use of bisphosphonate and calcimimetic agents for management of hypercalcemia.

Acute extracapsular parathyroid hemorrhage: case report and review of the literature

OBJECTIVE

To describe a patient with extracapsular parathyroid hemorrhage and review the signs and symptoms of this condition.

METHODS

We report a case of extracapsular parathyroid hemorrhage in a patient with primary hyperparathyroidism and present an overview of previously reported cases.

RESULTS

A 48-year-old woman with documented primary hyperparathyroidism, who was awaiting surgical intervention, had acute onset of a neck mass, neck pain, and dysphagia. She was found to have sustained a spontaneous extracapsular hemorrhage of a parathyroid adenoma. Hypercalcemia persisted, and she subsequently underwent curative parathyroidectomy for the primary hyperparathyroidism. We also identified 15 previously reported cases of extracapsular parathyroid hemorrhage and summarized the most common manifestations-most notably, a neck mass or swelling, ecchymoses of the neck and chest, dysphagia, neck pain, hoarseness, and dyspnea.

CONCLUSION

Clinicians should be aware of the potential for occurrence of extracapsular parathyroid hemorrhage in patients with primary hyperparathyroidism. When this condition occurs, severe hypercalcemia or acute hypocalcemia may be present. Hypercalcemia is often persistent; however, autoinfarction of the parathyroid adenoma is possible.

Parathyroid cancer: biology and management

A review of all reports in the literature of parathyroid carcinoma (PTC) was undertaken to define an optimal management strategy for this rare condition. PTC is uncommon and its etiology of PTC is largely unknown although patients with familial hyperparathyroidism, multiple endocrine neoplasia type 1 and irradiation to the head and neck are at increased risk for developing the disease. PTC occurs with equal frequency in both sexes and is usually diagnosed in the fifth decade. En bloc resection of the carcinoma and the adjacent structures in the neck is the surgical treatment and is associated with an 8% local recurrence rate and a long term overall survival rate of 89% (mean follow up 69 months). In contrast simple parathyroidectomy results in a 51% local recurrence rate and 53% long-term survival rate (mean follow up 62 months). Adverse prognostic factors for survival were initial management with simple parathyroidectomy alone, the presence of nodal or distant metastatic disease at presentation and non-functioning PTC.