Hyperparathyroidism after neck irradiation

Risk of Malignant Neoplasm in Patients with Primary Hyperparathyroidism: A Systematic Review and Meta-analysis

This study aimed to evaluate the prevalence and risk of malignant neoplasm in primary hyperparathyroidism (PHPT) patients. Potentially eligible studies were retrieved from PubMed and Embase databases from inception to November 2023 using search strategy consisting of terms for "Primary hyperparathyroidism" and "Malignant neoplasm". Eligible study must report prevalence of malignant neoplasm among patients with PHPT or compare the risk of malignant neoplasm between patients with PHPT and comparators. Point estimates with standard errors were extracted from each study and combined using the generic inverse variance method.A total of 11,926 articles were identified. After two rounds of systematic review, 50 studies were included. The meta-analysis revealed that pooled prevalence rates of overall cancer was 0.19 (95%CI: 0.13-0.25; I2 94%). The two most prevalent types of malignancy among patients with PHPT ware papillary thyroid cancer (pooled prevalence: 0.07; 95%CI: 0.06-0.08; I2 85%) and breast cancer (pooled prevalence: 0.05; 95%CI: 0.03-0.07; I2 87%). Subgroup analysis of studies focusing on patients undergoing parathyroidectomy reported a fourfold higher prevalence of papillary thyroid cancer than the remaining studies (0.08 versus 0.02). The meta-analysis of cohort studies found a significant association between PHPT and overall cancer with the pooled risk ratio of 1.28 (95%CI: 1.23-1.33; I2 66.9%).We found that the pooled prevalence of malignant neoplasm in PHPT was 19%, with papillary thyroid cancer and breast cancer being the most prevalent types. The meta-analysis of cohort studies showed that patient with PHPT carried an approximately 28% increased risk of malignancy.

Diagnostic dilemma in a rare case of nonfunctional parathyroid carcinoma at a referral facility in Northern Tanzania

Key Clinical Message

Rare cancer originating from parathyroid parenchymal cells. Preoperative diagnosis is often difficult. Presents with normal serum levels of calcium and parathyroid hormone. Treated by en bloc resection. Benefits of adjuvant therapy are unclear.

Abstract

Parathyroid carcinoma is an uncommon endocrine tumor. Its typical presentation is that of primary hyperparathyroidism with elevated serum calcium and parathormone levels. Nonfunctioning carcinoma of the parathyroid gland with normal serum calcium levels is extremely rare. This paper describes a case of nonfunctioning parathyroid carcinoma and brief literature review thereof.

Synchronous parathyroid carcinoma and papillary thyroid carcinoma

The simultaneous occurrence of parathyroid carcinoma and nonmedullary thyroid carcinoma is unusual. We report the case of 60‐year‐old woman who was found to have concurrent parathyroid carcinoma with severe clinical manifestations of primary hyperparthyroidism in addition to an incidental papillary thyroid carcinoma. Parathyroid hormone level was 569 pg/ml (normal range 10–65), and the serum calcium concentration was 13.83 mg/dl (normal range, 8.8–10.4). Preoperative investigation found a large 3 cm anterior cervical nodule suggestive of parathyroid adenoma. Total thyroidectomy and left parathyroidectomy were performed, and the final anatomopathological examination of the operative specimen concluded the coexistence of papillary microcarcinoma and parathyroid carcinoma. Although parathyroid carcinoma is an uncommon cause of hypercalcemia, it should be considered when severe hypercalcemia is observed, and in case of coexistence of thyroid nodules. The possibility of both malignancies must also be considered since parathyroid and nonmedullary thyroid carcinoma rare cases have previously been reported.

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.

Hyperparathyroidism subsequent to radioactive iodine therapy for Graves' disease

BACKGROUND

The development of primary hyperparathyroidism (PHPT) after radioactive iodine (RAI) treatment for thyroid disease is poorly characterized. The current study is the largest reported cohort and assesses the disease characteristics of patients treated for PHPT with a history of RAI exposure.

METHODS

A retrospective analysis comparing patients, with and without a history of RAI treatment, who underwent surgery for PHPT.

RESULTS

Twenty-eight of the 469 patients had a history of RAI treatment, all for Graves' disease. Patients with a history of RAI exposure had similar disease characteristics compared to control; however, patients with a history of RAI treatment had a higher rate of recurrence (7.4% vs 1.2%, p = 0.012).

CONCLUSION

PHPT in patients with a history of RAI treatment can be approached in the same manner as RAI naive PHPT patients; however, the risk of recurrence of PHPT in RAI exposed patients may be higher.

Parathyroid Disease in Pregnancy and Lactation: A Narrative Review of the Literature

Pregnancy and lactation are characterized by sophisticated adaptations of calcium homeostasis, aiming to meet fetal, neonatal, and maternal calcium requirements. Pregnancy is primarily characterized by an enhancement of intestinal calcium absorption, whereas during lactation additional calcium is obtained through resorption from the maternal skeleton, a process which leads to bone loss but is reversible following weaning. These maternal adaptations during pregnancy and lactation may influence or confound the presentation, diagnosis, and management of parathyroid disorders such as primary hyperparathyroidism or hypoparathyroidism. Parathyroid diseases are uncommon in these settings but can be severe when they occur and may affect both maternal and fetal health. This review aims to delineate the changes in calcium physiology that occur with pregnancy and lactation, describe the disorders of calcium and parathyroid physiology that can occur, and outline treatment strategies for these diseases in the above settings.

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.

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.

Pediatric Parathyroid Carcinoma: A Case Report and Review of the Literature

Primary hyperparathyroidism (PHPT) is a rare endocrine disease in the pediatric population. Sporadic parathyroid adenomas remain the most common cause of pediatric PHPT. Parathyroid carcinoma (PC) is an extremely rare cause of pediatric PHPT. We report a 16-year-old boy presenting with a nonhealing fragility fracture of the right leg along with florid features of rickets. Examination revealed a neck mass, mimicking a goiter. Biochemical findings were consistent with PHPT. Imaging was suggestive of a right inferior parathyroid mass infiltrating the right lobe of thyroid. The patient underwent en bloc surgical excision of the parathyroid mass along with the right lobe of thyroid. Histopathology was suggestive of a PC. He achieved biochemical remission with normalization of serum calcium and parathyroid hormone levels. At follow-up, there was no biochemical or imaging evidence of recurrence or metastasis. Genetic analysis revealed heterozygous germline deletion of CDC73. An extensive literature search on PC was conducted, with an emphasis on the pediatric population. Thirteen cases of pediatric PC were identified. The median age of presentation was 13 years; there was no sex predilection. All cases were symptomatic; 31% had a visible neck mass. The median serum calcium and intact parathyroid hormone levels were 14.3 mg/dL and 2000 pg/mL, respectively. All patients underwent surgical excision, with 27% showing metastatic relapse. Our findings indicate that the preoperative features that could point toward a diagnosis of PC in a child with PHPT are a tumor size of >3 cm, thyroid infiltration on imaging, and severe hypercalcemia at presentation.

MANAGEMENT OF ENDOCRINE DISEASE: Unmet therapeutic, educational and scientific needs in parathyroid disorders

PARAT, a new European Society of Endocrinology program, aims to identify unmet scientific and educational needs of parathyroid disorders, such as primary hyperparathyroidism (PHPT), including parathyroid cancer (PC), and hypoparathyroidism (HypoPT). The discussions and consensus statements from the first PARAT workshop (September 2018) are reviewed. PHPT has a high prevalence in Western communities, PHPT has a high prevalence in Western communities, yet evidence is sparse concerning the natural history and whether morbidity and long-term outcomes are related to hypercalcemia or plasma PTH concentrations, or both. Cardiovascular mortality and prevalence of low energy fractures are increased, whereas Quality of Life is decreased, although their reversibility by treatment of PHPT has not been convincingly demonstrated. PC is a rare cause of PHPT, with an increasing incidence, and international collaborative studies are required to advance knowledge of the genetic mechanisms, biomarkers for disease activity, and optimal treatments. For example, ~20% of PCs demonstrate high mutational burden, and identifying targetable DNA variations, gene amplifications and gene fusions may facilitate personalized care, such as different forms of immunotherapy or targeted therapy. HypoPT, a designated orphan disease, is associated with a high risk of symptoms and complications. Most cases are secondary to neck surgery. However, there is a need to better understand the relation between disease biomarkers and intellectual function, and to establish the role of PTH in target tissues, as these may facilitate the appropriate use of PTH substitution therapy. Management of parathyroid disorders is challenging, and PARAT has highlighted the need for international transdisciplinary scientific and educational studies in advancing in this field.

Long-Term Endocrine and Metabolic Consequences of Cancer Treatment: A Systematic Review

The number of patients surviving ≥5 years after initial cancer diagnosis has significantly increased during the last decades due to considerable improvements in the treatment of many cancer entities. A negative consequence of this is that the emergence of long-term sequelae and endocrine disorders account for a high proportion of these. These late effects can occur decades after cancer treatment and affect up to 50% of childhood cancer survivors. Multiple predisposing factors for endocrine late effects have been identified, including radiation, sex, and age at the time of diagnosis. A systematic literature search has been conducted using the PubMed database to offer a detailed overview of the spectrum of late endocrine disorders following oncological treatment. Most data are based on late effects of treatment in former childhood cancer patients for whom specific guidelines and recommendations already exist, whereas current knowledge concerning late effects in adult-onset cancer survivors is much less clear. Endocrine sequelae of cancer therapy include functional alterations in hypothalamic-pituitary, thyroid, parathyroid, adrenal, and gonadal regulation as well as bone and metabolic complications. Surgery, radiotherapy, chemotherapy, and immunotherapy all contribute to these sequelae. Following irradiation, endocrine organs such as the thyroid are also at risk for subsequent malignancies. Although diagnosis and management of functional and neoplastic long-term consequences of cancer therapy are comparable to other causes of endocrine disorders, cancer survivors need individually structured follow-up care in specialized surveillance centers to improve care for this rapidly growing group of patients.

Parathyroid Carcinoma in Patients that Have Undergone Surgery for Primary Hyperparathyroidism

BACKGROUND/AIM

Parathyroid carcinoma is a rare clinical entity, which represents one of the main reasons, why surgery should be performed in specialized centres. Preoperatively, it is very difficult to distinguish between benign and malignant hyperparathyroidism.

PATIENTS AND METHODS

During the years 1996-2016, we performed 2,220 operations in 2,075 patients with a diagnosis of primary hyperparathyroidism.

RESULTS

Among these 2,220 operations, there were 16 operations for parathyroid carcinoma. These 16 operations, including reoperations, were performed in four patients. Two patients had no reoperation, but another 2 patients required 14 reoperations in total. Parathyroid carcinoma was described in 0.2% of all patients with a diagnosis of primary hyperparathyroidism. The number of operations was 0.73% of all operations of primary hyperparathyroidism in years 1996-2016.

CONCLUSION

Prognosis of parathyroid carcinoma is quite favourable, patients evidence a long-term survival rate after the primary operation. However, every reoperation increases the number of possible complications, including recurrent laryngeal nerve injury.

Parathyroid cancer and the CDC73 tumor suppressor gene

Parathyroid carcinoma (PC) is a rare endocrine neoplasm, usually causing severe primary hyperparathyroidism, that frequently causes death from unmanageable hypercalcemia. PC is frequently associated with somatic inactivating mutations of the CDC73 gene (previously called HRPT2), a gene discovered in association with the familial hyperparathyroidism-jaw tumor syndrome. DNA analysis for CDC73 mutation should be performed on all patients with seemingly sporadic PC since some 25% will carry a germline mutation. It is often difficult to make a firm diagnosis of PC by histopathology alone. That diagnosis often depends on the presence of local tissue invasion or distant metastases. If PC is suspected, en bloc resection at initial surgery is recommended. Medical therapy with cinacalcet, bisphosphonates or denosumab may temporarily ameliorate the hypercalcemia of inoperable PC.

Parathyroid carcinoma in pregnancy

A 24-year-old female patient with parathyroid carcinoma, the rarest endocrine malignancy, had two pregnancies. In the first pregnancy, she had severe nausea and fatigue. Hypercalcemia and hyperparathyroidism were diagnosed in the postpartum period. Hyperemesis gravidarum masked a diagnosis of hypercalcemia. Neck ultrasound and Tc-99m sestamibi found an enlarged lower right parathyroid gland. The gland was surgically removed, and an initial pathology report described atypical adenoma. Shortly afterward, she became pregnant again. During the second pregnancy, her calcium level was frequently controlled but was always in the normal range. Normocalcemia is explained by the specific physiology of pregnancy accompanied by hemodilution, hypoalbuminemia and maternal hypercalciuria (mediated by increased glomerular filtration). During lactation, calcium levels rose, and a new neck ultrasound showed a solitary mass in the area of prior surgery and an enlarged pretracheal lymph node. Fine needle aspiration of the solitary mass and node showed parathyroid carcinoma cells. The tumor mass was resected en bloc with the contiguous tissues and surrounding lymph nodes (pathology report; parathyroid carcinoma with metastases). Over the next five years, four consecutive surgeries were performed to remove malignant parathyroid tissue, lymph nodes and local metastases. Following the surgical procedures, no hypocalcemia was observed. More serious hypercalcemia recurred; the calcium level was difficult to control with a combination of pamidronate, cinacalcet and loop diuretic. No elements of multiple endocrine neoplasia were present.

Parathyroid carcinoma

Parathyroid carcinoma is a rare form of endocrine malignancy accounting for only a small minority of cancer cases. Due to the rarity of this cancer, there are no generalized guidelines for its management; however, surgery remains to be the mainstay therapy. The purpose of this article is to review and summarize the available literature on parathyroid carcinoma, while discussing proposed staging systems and the role of available adjuvant therapies.

Two Cases of Metastatic Parathyroid Carcinoma in Male C3H Mice Following Irradiation

White nodules were observed in the thyroid in two male C3H mice (at 99 and 122 weeks of age) exposed to fast neutrons at the age of 8 weeks. Histopathologically, in both cases, tumors were developed in the region corresponding to the parathyroid gland, and the tumor cells were arranged in a solid sheet or nest-like structures. Necrosis, cell debris and/or hemorrhage were sometimes seen in the center of the tumor structures. Tumor cells were small and uniform with scanty cytoplasm, cell margins were indistinct, and basally located tumor cells were aligned along the vascular stroma. Mitotic figures were frequently observed. Metastasis to the renal cortex was observed in both cases. These cases were diagnosed as parathyroid carcinoma. A parathyroid tumor is an extremely rare endocrine tumor in mice, regardless of whether the tumor is spontaneous or experimentally induced. These cases may have been induced by neutron-exposure; however, how radiation induces parathyroid carcinoma in mice is not clear.

Parathyroid cancer

Parathyroid cancer is an uncommon malignancy and rare cause of primary hyperparathyroidism (HPT) with a high morbidity and patient death in advanced cases usually resulting from intractable hypercalcemia. Inactivation of the HRPT2/CDC73 gene, encoding the putative tumor-suppressor protein parafibromin and discovered in the context of the hyperparathyroidism-jaw tumor (HPT-JT) syndrome, is a common, somatic event in most parathyroid cancers. Approximately 25% of patients with apparently sporadic parathyroid cancer carry germline HRPT2/CDC73 mutation. Germline DNA analysis for HRPT2/CDC73 mutation is recommended in all patients with parathyroid cancer because of the potential benefit for first-degree relatives, who should nevertheless undergo serum calcium screening. The histopathologic diagnosis of parathyroid cancer is nonspecific unless vascular, lymphatic, capsular, or soft tissue invasion is seen, or metastases are clinically evident. Immunohistochemical analysis of parathyroid tumors for loss of parafibromin expression offers promise as a diagnostic tool. En bloc tumor resection offers the highest chance of cure in patients with suspected parathyroid carcinoma. No adjuvant chemotherapy regimen has yet proven effective, and the role of local adjuvant radiotherapy is being evaluated. Metastatic disease can be palliated with surgical debulking. Medical therapy with the calcimimetic cinacalcet and bisphosphonates can ameliorate hypercalcemia in patients with inoperable disease.

Challenges and pitfalls in the management of parathyroid carcinoma: 17-year follow-up of a case and review of the literature

A 29-year-old man presented to his primary care physician with nausea, severe weight loss and muscle weakness. He had a hard, fixed neck swelling. He was severely hypercalcaemic with 10-fold increased parathyroid hormone (PTH) concentrations. A diagnosis of primary hyperparathyroidism was established and the patient was referred for parathyroidectomy. At neck exploration, an enlarged parathyroid gland with invasive growth into the thyroid gland was found and removed, lymph nodes were cleared and hemithyroidectomy was performed. A suspected diagnosis of parathyroid carcinoma was confirmed histologically. Serum calcium and PTH levels normalised post-operatively, but hyperparathyroidism recurred within 3 years of surgery. Over the following 17 years, control of hypercalcaemia represented the most difficult challenge despite variable success achieved with repeated surgical interventions, embolisations, radiofrequency ablation of metastases and treatment with calcimimetics, bisphosphonates and haemodialysis using low-dialysate calcium. In this paper, we report the challenges and pitfalls we encountered in the management of our patient over nearly two decades of follow-up and review recent literature on the topic.

Parathyroid adenoma and chondrosarcoma after treatment of pediatric Hodgkin disease

Treatment of Hodgkin disease (HD) with chemoradiotherapy in children is associated with increased risk for developing secondary neoplasms. Parathyroid adenoma (PTA) and chondrosarcoma (CS) are quite rare types of secondary neoplasms after HD. We describe a 5-year-old boy with stage IV HD, successfully treated with MOPP (mechlorethamine, vincristine, procarbazine, and prednisone)/ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapy followed by 35 Gy mantle radiotherapy who developed primary hyperparathyroidism because of benign PTA at the age of 20 years, and died of CS in thoracic vertebrae at the age of 22 years. Consecutive occurrence of PTA and CS after treatment of pediatric HD, to the best of our knowledge, has not been reported earlier.

Focus on parathyroid carcinoma

Parathyroid carcinoma is a malignant neoplasm affecting 05-2 per cent of all patients with primary hyperparathyroidism that was first described by de Quevain in 1904. To day it continues to defy diagnosis and treatment. It is difficult to diagnose in part because of its rarity, lack of definitive diagnostic markers and overlapping clinical features of benign primary hyperparathyroidism. As a result initial surgical treatment is inadequate essentially leading to disease recurrence where complete cure is unlikely. En bloc surgical resection remains the only curative treatment, and high priorities are improving diagnostic methods, and clinical staging for resection once the disease is suspected. Margin status at resection is related to prognosis. Thus, a trend towards aggressive surgical management has improved outcomes. The recurrence rate of parathyroid carcinoma is as high as 80% with survival rates <50% at 10 years. Results of chemotherapy are disappointing. However, recent trials using radiation therapy are promising, but require further study.

Parathyroid carcinoma

Parathyroid carcinoma is a rare endocrine malignancy. The reported incidence is from 0.5 to 5% of primary hyperparathyroidism cases in various series. The cause is unknown, but clinical correlations with different genetic syndromes exist. Mutations in the HPRT2 gene seem to play a significant role in the pathogenesis of this disease. Men and women are equally affected, usually in the fourth or fifth decade of life. Most patients will present with signs and symptoms of hypercalcaemia. Cases of non-functioning carcinoma are exceedingly rare. Surgical resection is the most effective method of treatment and palliation. A significant proportion of patients will experience recurrence, and will need further surgical and, eventually, medical management of hypercalcaemia. The disease is progressive but slow growing. Most patients will require multiple operations to resect recurrent disease. The main cause of morbidity and mortality is the sequela of uncontrolled chronic hypercalcaemia rather than tumour burden. The current paper will review the epidemiology, pathogenesis, clinical presentation and diagnostic work-up of this disease. Surgical management in different scenarios is reviewed in detail, followed by other types of treatment and management of incurable disease.

Synchronous parathyroid carcinoma, parathyroid adenoma, and papillary thyroid carcinoma in a patient with severe and long-standing hyperparathyroidism

OBJECTIVE

To describe a patient presenting with the rare constellation of synchronous parathyroid carcinoma, parathyroid adenoma, and papillary thyroid carcinoma.

METHODS

We summarize the clinical presentation, diagnostic work-up, surgical management, and pathologic features of our patient and review the pertinent literature.

RESULTS

The patient was a 59-year-old man who presented with severe clinical manifestations of long-standing primary hyperparathyroidism, a serum calcium concentration of 14.4 mg/dL, and a parathyroid hormone level of 2,023 pg/mL. He was found to have a 3.4-cm parathyroid carcinoma on the left side and a 3.2-cm papillary carcinoma in the right thyroid lobe. In addition, a 917-mg parathyroid adenoma was found on the right side.

CONCLUSION

Synchronous parathyroid and thyroid carcinomas are extremely rare. To our knowledge, our patient is the first documented case with a parathyroid adenoma in addition to synchronous parathyroid and thyroid carcinomas. The presence of concurrent parathyroid carcinoma and parathyroid adenoma can cause diagnostic confusion and should be considered in patients presenting with severe hyperparathyroidism. Any concomitant thyroid nodules must be investigated to rule out thyroid carcinoma.

Risk of parathyroid adenomas in patients with thyrotoxicosis exposed to radioactive iodine

External ionizing radiation is a risk factor for primary hyperparathyroidism. Whether exposure to radioactive iodine contributes to the risk of primary hyperparathyroidism is unknown. Patients with thyrotoxicosis are often treated with radioactive iodine and its accumulation in the thyroid gland exposes the adjacent parathyroid glands to radioactivity. Six thousand and eighty two patients with thyrotoxicosis (ICD-9 = 242) were identified from medical records. In a randomly selected subcohort we assessed the frequency of treatment with radioactive iodine to be 86%. The number of patient-years at risk was 77,118. Patients with parathyroid adenomas (ICD-9 = 195.1) were recruited from the Swedish Cancer Registry. Eleven patients with parathyroid adenomas following the diagnosis of thyrotoxicosis were identified. The standard incidence ratio (SIR) compared to the reference population of approximately 900,000 was 1.14 (95% CI 0.57-2.03). The median age at exposure was 59 years and the latency period between diagnosis of thyrotoxicosis and parathyroid adenoma was 7.4 years (range <1-19 years). This study does not indicate that patients with thyrotoxicosis treated with radioactive iodine in adult age have increased risk of developing parathyroid adenoma.

Skeletal sequelae of cancer and cancer treatment

INTRODUCTION

Survivors of cancer may experience lingering adverse skeletal effects such as osteoporosis and osteomalacia. Skeletal disorders are often associated with advancing age, but these effects can be exacerbated by exposure to cancer and its treatment. This review will explore the cancer and cancer treatment-related causes of skeletal disorders.

METHODS

We performed a comprehensive search, using various Internet-based medical search engines such as PubMed, Medline Plus, Scopus, and Google Scholar, for published articles on the skeletal effects of cancer and cancer therapies.

RESULTS

One-hundred-forty-two publications, including journal articles, books, and book chapters, met the inclusion criteria. They included case reports, literature reviews, systematic analyses, and cohort reports. Skeletal effects resulting from cancer and cancer therapies, including hypogonadism, androgen deprivation therapy, estrogen suppression, glucocorticoids/corticosteroids, methotrexate, megestrol acetate, platinum compounds, cyclophosphamide, doxorubicin, interferon-alpha, valproic acid, cyclosporine, vitamin A, NSAIDS, estramustine, ifosfamide, radiotherapy, and combined chemotherapeutic regimens, were identified and described. Skeletal effects of hyperparathyroidism, vitamin D deficiency, gastrectomy, hypophosphatemia, and hyperprolactinemia resulting from cancer therapies were also described.

DISCUSSION/CONCLUSIONS

The publications researched during this review both highlight and emphasize the association between cancer therapies, including chemotherapy and radiotherapy, and skeletal dysfunction.

IMPLICATIONS FOR CANCER SURVIVORS

These studies confirm that cancer survivors experience a more rapid acceleration of bone loss than their age-matched peers who were never diagnosed with cancer. Further studies are needed to better address the skeletal needs of cancer survivors.

[Primary hyperparathyroidism in special situations: multiple endocrine neoplasia syndromes and parathyroid cancer]

Primary hyperparathyroidism (PHP) is a known endocrine disorder. Many years ago, the most frequent forms of clinical presentation were symptomatic renal or skeletal disease with moderate or severe hypercalcemia; however, currently, most patients have few symptoms and mild hypercalcemia. The last NIH Workshop on Asymptomatic PHP developed criteria for the management of this disease. Multiple endocrine neoplasia (MEN) types 1 and 2 are two genetic syndromes caused by different types of molecular abnormalities. PHP is the most common manifestation of MEN-1 and is the last feature to appear in MEN 2A. Parathyroid carcinoma (PC) is a rare neoplasm and an uncommon cause of parathyroid hormone (PTH)-dependent hypercalcemia. In this report, the treatment of PHP in MEN syndrome and PC are reviewed. Special attention is paid to a new class of drugs called "calcimimetics", which are powerful compounds that may be highly useful in the treatment of both conditions.

[Parathyroid carcinoma: multicenter study of 17 patients]

PURPOSE OF THE STUDY

To evaluate clinical characteristics and survival of patients treated for parathyroid carcinoma.

STUDY DESIGN

A retrospective multicenter chart review of patients treated for parathyroid carcinoma between January 1979 and January 2005.

RESULTS

17 patients (10 women, 7 men) presenting with parathyroid carcinoma underwent surgical resection. Symptoms were largely related to hypercalcemia. Mean postoperative follow-up was seven years. Local recurrence was noted in four patients (24%) and three patients had late distant metastasis (18%). At the end of the study, nine patients were alive without evidence of recurrence (53%) and one patient was alive with recurrence at 5 years. Seven patients had died, four of whom died as a result of their parathyroid disease.

CONCLUSION

Even when symptoms and findings are suggestive, the diagnosis of parathyroid carcinoma is oftentimes difficult. An adequate resection at the first intervention (complete tumor resection including a homolateral thyroid lobectomy and parathyroidectomy with resection of central lymph nodes) is recommended.

[Hyperparathyroidism, goiter and well-differentiated thyroid carcinoma. A common association with diagnostic implications]

OBJECTIVE

To analyze thyroid gland disease incidentally found in patients undergoing surgery for hyperparathyroidism and to compare the frequency of nonmedullary thyroid carcinoma among different hyperparathyroidism varieties.

PATIENTS AND METHOD

We retrospectively reviewed 124 clinical records of patients who underwent surgery for hyperparathyroidism by a single surgeon from January 1998 to June 2006.

RESULTS

There were 105 women (84.7%) and 19 men (15.3%). The mean age was 59.7 +/- 15.66 years old. Of these, 115 (92.7%) were diagnosed with primary hyperparathyroidism and 9 (7.3%) with renal hyperparathyroidism. In the primary hyperparathyroidism group, 3 patients (2.6%) had received neck irradiation compared with none in the renal hyperparathyroidism group. Thyroid gland surgery was performed simultaneously in 43 patients (34.7%), 40 (34.8%) of them belonging to the first group and three (33.3%) to the second group (p = 1.00). Among the 115 patients operated on for primary hyperparathyroidism, 6 papillary thyroid carcinomas (5.2%) were found and 2 (22.2%) were found among the 9 patients with renal hyperparathyroidism, but this difference was not statistically significant (p = 0.105).

CONCLUSIONS

An incidental finding of thyroid disease in patients undergoing surgery for hyperparathyroidism is fairly frequent but no more so than that found in autopsy series. No statistically significant differences were found between primary and renal hyperparathyroidism in the prevalence of papillary thyroid carcinoma. Currently, neck irradiation does not seem to be a clinically significant factor in this issue. The high prevalence of thyroid disease in the general population warrants systematic neck ultrasound before hyperparathyroidism surgery.

Hyperparathyroidism after radioactive iodine therapy

BACKGROUND

Radioactive iodine (RAI) treatment has been suggested to cause primary hyperparathyroidism (HPT). We describe a series of patients with HPT and a history of RAI exposure.

METHODS

Patient demographic and clinical information was evaluated, including the latency time to the development of HPT after RAI exposure.

RESULTS

We treated 11 patients with HPT and a history of RAI exposure. RAI treatment was administered for benign thyroid disease in 9 (82%) cases. Thirty-six cases of HPT after RAI exposure in the English literature were compiled for further analysis. In this collective experience, the average latency time to the development of HPT after RAI treatment was 13.5 +/- 9.1 years and was found to be inversely correlated with age at RAI exposure.

CONCLUSIONS

Patients who undergo RAI treatment are at risk of developing HPT, and this risk appears to increase in elderly patients. Serum calcium surveillance is recommended for patients who have undergone RAI treatment.

Intraoperative diagnosis and treatment of parathyroid cancer and atypical parathyroid adenoma

Background

Distinction of parathyroid cancer from atypical parathyroid adenoma (APA) at operation is difficult. The aim of this study was to determine whether parathyroid cancer and APA have different operative findings and long-term outcomes.

Methods

A retrospective review was undertaken of patients with suspicious or malignant parathyroid tumours treated between 1974 and 2005. Parathyroid cancer was defined as a lesion with vascular or tissue invasion, and APA as a neoplasm with broad fibrous bands, trabecular growth, mitosis and nuclear atypia.

Results

Twenty-seven patients with suspicious or malignant parathyroid tumours were identified. After histological review, parathyroid cancer was confirmed in 11 patients (group 1) and 16 tumours were classified as APA (group 2). The clinical presentation and operative findings of the two types of tumour were indistinguishable. At initial surgery, seven patients in group 1 underwent en bloc resection, and four had parathyroidectomy. Four of the seven patients who had en bloc resection had recurrences. No recurrences were observed in the other seven patients in group 1 at a median follow-up of 65 months. In group 2, eight patients had en bloc resection and eight had parathyroidectomy; no patient had recurrence at a median follow-up of 91 months.

Conclusion

Operative findings cannot distinguish APA from parathyroid cancer reliably. Without evidence of macroscopic local invasion, the value of en bloc resection at initial surgery remains debatable.

Use of pre-operative Tc99m-Sestamibi scintigraphy and intraoperative parathyroid hormone monitoring to eliminate neck exploration in mediastinal parathyroid adenocarcinoma

A 66-year-old white woman was found to have an elevated serum calcium and parathyroid hormone (PTH) on routine health evaluation. Physical examination was unremarkable as was ultrasonography of the neck. A sestamibi parathyroid scan revealed abnormal uptake in the anterior mediastinum. Computed tomography of the chest demonstrated an anterior mediastinal mass compatible with a parathyroid adenoma but no neck masses. The patient underwent mediastinoscopy that was converted to a median sternotomy to fully access the mass. The mass was completely resected with surrounding thymus gland. Frozen section confirmed that excised tissue was parathyroid gland in origin. An intraoperative PTH obtained 20 minutes after specimen removal showed a decrease of more than 50% from preoperative levels. The strategy for initial surgery for hyperparathyroidism when a sestamibi scan is "positive" in the mediastinum (only) is a point of some controversy. Traditional recommendations have been to "clear the neck" of abnormal parathyroid tissue before undertaking a more morbid sternotomy. Mediastinoscopy was attempted to remove the mediastinal lesion and to avoid a sternotomy. Preoperative Tc99m sestamibi scintigraphy, frozen section histology, and intraoperative PTH monitoring permitted the authors to conclude that neck exploration was unnecessary.

Parathyroid Cancer

Parathyroid cancer is a rare endocrine tumor and an uncommon cause of HPT. Advances have been made to identify a promising molecular diagnostic marker for the disease. The use of accurate preoperative imaging modalities would undoubtedly facilitate its management by making an accurate preoperative diagnosis by assessing its invasiveness, and by searching for nodal or distant metastases. The effectiveness of the application of intraoperative PTH assay in the management of this rare condition remains to be seen. Radical surgical treatment offers the best chance of cure, but for patients who have refractory unresectable disease or metastases, the availability of more effective targeted medical therapy may palliate the debilitating symptoms of hypercalcemia, reduce its metabolic complications, and potentially improve survival.

One stage treatment of parathyroid cancer

AIM

To review the methods of treating parathyroid cancer in our series and report successful use of intraoperative frozen section to enable one stage surgical management.

METHOD

Seven cases of parathyroid cancer presented from 1991-2002. The presenting features, diagnosis and treatment are presented. They are separated into two groups based on method of referral and treatment.

RESULTS

Patients presented with symptoms of hypercalcaemia. Median corrected calcium was 3.49 mmol/l. Parathyroid hormone levels were raised in seven of eight cases, range 14.5-495 pmol/l. A high index of pre-operative suspicion and use of frozen section enabled a one step surgical procedure. Recurrence was impossible to treat successfully. Radiotherapy appeared successful for residual disease.

CONCLUSION

A high pre-operative index of suspicion for parathyroid carcinoma with use of frozen section at time of operation permits an optimal one step surgical procedure by en bloc resection followed by central lymph node excision. In cases where diagnosis has been made post-operatively radiotherapy may be beneficial.

Parathyroid carcinoma: a 22-year experience

PURPOSE

Because parathyroid carcinoma is rare, clear consensus is not available regarding the optimal management of patients with this condition. Treatment strategies generally derive from clinical and anecdotal experiences. We report our experience with this entity.

METHODS

We included all patients with parathyroid carcinoma seen at The University of Texas M. D. Anderson Cancer Center since January 1, 1980. The medical records and pathology specimens were reviewed and verified in all cases.

RESULTS

Since 1980, 27 patients (16 men and 11 women) registered at M. D. Anderson Cancer Center with parathyroid carcinoma and a minimum follow-up of 2 years. The age at initial diagnosis (mean +/- SD) was 46.7 +/- 15.3 years. All patients were seen with hypercalcemia (mean calcium, 13.4 +/- 1.5 mg/dL). Eighteen patients had locally invasive disease, eight had localized disease, and one had distant metastasis. Parathyroid cancer was treated with complete surgical excision with curative intent in 18 patients. In the other nine patients, who had clinical and/or radiographic evidence of soft tissue extension, the tumor was treated by comprehensive "en bloc" soft tissue resection. Of six patients who received adjuvant radiotherapy after initial surgery, only one had a local relapse. In contrast, of 20 patients who did not receive adjuvant radiotherapy, 10 had a local relapse, excluding the one patient who had distant metastases. The 5-year survival was 85%, and the 10-year survival was 77%. Five patients died of parathyroid carcinoma; all deaths were hypercalcemia related.

CONCLUSIONS

Parathyroid carcinoma can be an indolent disease with morbidity and mortality related to hypercalcemia. Adjuvant radiotherapy may improve local control and limit the occurrence of local relapse. A comprehensive multidisciplinary approach with surgery, radiation therapy, and medical treatment for hypercalcemia is needed to optimize patient outcome.

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.

Up-to-date on parathyroid carcinoma: analysis of an experience of 19 cases

BACKGROUND AND OBJECTIVES

Parathyroid carcinoma (PC) is a rare disease; experience with its management is limited. The aim of this retrospective study was to evaluate a relatively large series of patients suffering from PC.

METHODS

Since 1980, PC was diagnosed in the 4.7% of cases of primary hyperparathyroidism (HPT) (19 patients). Clinical and biochemical features, and surgical outcome were analyzed.

RESULTS

In patients with PC, the mean serum calcium was 3.34 mmol/L; the tumor size 30.5 mm. Malignancy was never diagnosed preoperatively. Thirty-two operations were performed; six patients underwent repeated surgery. Recurrence of HPT was observed in 100% of patients. The median disease-free interval was 15 months (range 2-74 months). Fifteen patients died because of the disease; median survival was 29 months (range 20-146 months). A significant correlation was found between late recurrences and prolonged survival; less advanced age and higher preoperative calcium levels predicted early recurrences.

CONCLUSIONS

Preoperative diagnosis of PC is difficult. Preoperative severe hypercalcemia should alert the surgeon. En bloc resection of the PC and the adjacent structures is the treatment of choice. Unfortunately, recurrences are common and long-term survival rate is low.

Parathyroid Carcinoma: A Multicenter Review of Clinicopathologic Features and Treatment Outcomes

We conducted a retrospective study of 13 patients with parathyroid carcinoma to assess their clinical characteristics and surgical outcomes. Study parameters included patient demographics, survival, treatment response, and recurrence. We found that all patients who had undergone local tumor excision developed a recurrence, compared with only 33% of those available for follow-up after en bloc tumor resection. Based on these findings, we recommend en bloc tumor resection as the initial treatment of choice for patients diagnosed with parathyroid carcinoma.

Parathyroid Cancer, a Continued Diagnostic and Therapeutic Dilemma: Report of Four Cases and Review of the Literature

Parathyroid cancer presents a diagnostic challenge as a rare endocrine malignancy usually not recognized preoperatively and often not conclusively identified intraoperatively. We examined a cluster of parathyroid cancers treated at University of Louisville-affiliated hospitals during a 5-year interval. Clinical and histologic data from patient records at University Surgical Associates, the University of Louisville Hospital, Norton Hospital, and the Louisville Veterans Administration Medical Center in Louisville, KY were retrospectively reviewed. During the study interval surgical exploration of the neck was undertaken on 175 patients with primary hyperparathyroidism; four parathyroid malignancies (2%) were identified. Three of the four patients exhibited symptomatic hyperparathyroidism with very high diagnostic calcium and parathormone levels. All patients had multiple coexisting diseases and two had undergone previous parathyroid surgery. Sestamibi scan localized the lesion in two patients, ultrasound was used in one patient, and a positron emission tomography scan was needed to identify the lesion in the fourth. Intraoperative findings varied from multiple nodules involving the thyroid and paratracheal nodules to otherwise normal-appearing enlarged parathyroid gland. External pathologic review was needed to conclusively establish the diagnosis in all cases, even though initial histologic analysis was suggestive of malignancy. All patients are alive, well, and free of disease. This rarely occurring malignancy may be suggested by very high preoperative calcium parathormone levels. Intraoperative and histologic findings are often inconclusive resulting in therapeutic decisions made by the operating surgeon on the basis of limited or incomplete information.

Mutational analyses of RB and BRCA2 as candidate tumour suppressor genes in parathyroid carcinoma

OBJECTIVE

Strong evidence indicates that at least one key tumour suppressor gene important for the development of malignant parathyroid tumours is located on chromosome 13, but the critical target gene remains unknown. Importantly, the region of acquired DNA loss includes two established tumour suppressor genes, the retinoblastoma gene, RB (RB1) and BRCA2. Resolution of whether RB or BRCA2 is the critical 13q tumour suppressor gene in parathyroid cancer requires analysis of these genes' sequences for intragenic inactivating mutations. Therefore, RB and BRCA2 were analysed in a group of parathyroid carcinomas in which mutations of these genes should be most readily detectable.

PATIENTS AND DESIGN

Six parathyroid carcinomas from four patients which showed loss of heterozygosity (LOH) at the RB locus and/or 13q loss by comparative genomic hybridazation (CGH) were selected from a CGH/LOH-screened panel of 16 carcinoma specimens from 10 patients. These tumours were examined for mutations by direct sequencing of the complete 27-exon coding region, intron-exon boundaries and promoter of RB. The 26 coding exons and intron-exon boundaries of BRCA2 were also directly sequenced in seven parathyroid carcinomas with loss in the BRCA2 region.

RESULTS

No microdeletions, insertions, or point mutations were detected in either RB or BRCA2 in any of the carcinomas.

CONCLUSION

The absence of tumour-specific somatic mutations in RB and BRCA2 suggests that they are unlikely to act as classic tumour suppressor genes in the pathogenesis of parathyroid carcinomas. While decreased expression of these genes might contribute to parathyroid carcinomatosis in a secondary fashion and 13q loss warrants further study as a diagnostic marker for parathyroid carcinoma, the putative 13q tumour suppressor awaits identification.

Prolactinoma and other head and neck tumors after scalp irradiation

Tumors of the thyroid and parathyroid glands may develop together or separately in patients who previously have been exposed to head and neck irradiation. Whether cranial irradiation confers an increased risk for pituitary adenoma remains unknown. We report the case of a 52-year-old woman who was treated during childhood for tinea capitis with scalp irradiation and later in life developed a prolactin-secreting tumor, a parathyroid adenoma, a benign thyroid lesion, and a basal cell carcinoma of the skin. She was treated successfully with bromocriptine and surgical removal of the parathyroid adenoma. Molecular analysis of the parathyroid tissue failed to demonstrate any abnormality of the multiple endocrine neoplasia Type 1 gene. This case report is the first to describe a prolactin-secreting tumor that developed in association with other endocrine neoplasia after head and neck irradiation. Our case suggests that multiple endocrine neoplasia may develop in a sporadic pattern after scalp irradiation.

Increased incidence of parathyroid adenomas following X-ray treatment of benign diseases in the cervical spine in adult patients

OBJECTIVE

To determine whether or not exposure to ionizing radiation as an adult increases the risk of developing parathyroid adenomas.

DESIGN AND PATIENTS

A cohort of 27 415 patients had received X-ray treatment to palliate pain originating from arthrosis and spondylosis from 1950 to 1964. In a subcohort of 8144 patients the cervical spine was the target, or one of the targets for the treatment. With the technique used it could be assumed that, as a rule, the parathyroid glands had been included in the treated volume. Patients with parathyroid adenomas were obtained from the Swedish Cancer Register from 1958 to 1995. The standardized incidence ratio (SIR) was calculated.

RESULTS

The number of person-years at risk was 180 492 in the cohort exposed at the cervical spine, and 412 994 in the control cohort irradiated only at other sites. The calculated dose in the parathyroid region in the study cohort was about 1 Gy. The observed number of parathyroid adenomas in the study cohort was 22, and 24 in the control cohort. Expected numbers based on population data were 12.0 and 24.7, respectively, giving an SIR of 1.83 (95% CI 1.14-2.76) and 0.97 (CI 0.62-1.45), respectively. Mean age at exposure was 48.9 years (SD 10.2) and at diagnosis 71.5 years (SD 8.3). The time from exposure to diagnosis varied from 2 to 34 years (median 26 years). The excess relative risk was about 0.8 per Gy.

CONCLUSION

Exposure to ionizing radiation to the cervical spine in adult age seems to be associated with an increased risk of developing parathyroid adenomas.

Dose-response relationship for parathyroid adenoma after exposure to ionizing radiation in infancy

Several authors have suggested that there is an excess risk of hyperparathyroidism, adenomas or hyperplasia after exposure to ionizing radiation. There is still, however, some uncertainty about this association, because these diseases are often asymptomatic and escape clinical detection if not specially searched for. This study is based on a pooled Swedish cohort of 27,925 persons with skin hemangiomas. The majority received radiation treatment in infancy between 1920 and 1965 in Stockholm and Gothenburg. The mean age at treatment was 6 months and the median thyroid dose was 0.20 Gy (range 0-28.5 Gy). Record linkage with the Swedish Cancer Register for the period 1958-1997 gave 43 cases of parathyroid adenoma in the cohort. Analyses of excess relative risk (ERR) models were performed using Poisson regression methods. Clinical records were scrutinized to determine if the childhood radiation exposure was known (biased cases) at the time of diagnosis. Seven of the cases of parathyroid adenoma were classified as biased cases. The standardized incidence ratio (SIR) was 2.10 (95% confidence interval 1.52-2.82) when all cases were included and 1.76 (95% CI 1.23-2.43) with the biased cases excluded. A linear dose-response model with stratification for sex fitted the data best. The ERR per gray was 3.84 (95% CI 1.56-8.99) with all cases and 1.56 (95% CI 0.36-4.45) with the biased cases excluded. There was a significant difference in the ERR per gray between the two subcohorts, probably because of different diagnostic activity in the regions. Our findings confirm that there is a dose-response relationship for radiation-induced parathyroid adenomas.

Parathyroid adenoma after radioactive iodine therapy for multinodular goiter

The development of hyperparathyroidism after radioactive iodine (RAI) therapy has been reported in 38 cases in the literature. However, the development of a parathyroid adenoma after RAI therapy for a hyperfunctioning multinodular goiter has not been reported. This report describes the pathologic and operative finding on a patient with both hyperthyroidism and hyperparathyroidism, which was diagnosed after previous RAI therapy for a toxic, multinodular goiter.

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.