A single-institution 25-year review of true parathyroid cysts

Characterisation of Kürsteiner canals of parathyroid: imparting relevance to a one-and-a-quarter-century-old concept

AIMS

Kürsteiner canals (KC) were described at least 125 years ago as pharyngeal pouch embryological remnants of parathyroid and thymic development. While considered precursors for a subset of parathyroid cysts and salivary heterotopias (SH), they remain enigmatic. We now define a comprehensive phenotype of KC remnants and investigate their role in a spectrum of parathyroid lesions.

METHODS AND RESULTS

`Sixty-two cystic and 22 non-cystic parathyroid lesions (73 patients) were retrieved from our institutional archive (2011-23) and evaluated for the presence of KC and prevalence of KC phenotype in parathyroid hormone (PTH)-positive and PTH-negative cysts. KC phenotype was defined as: cysts and tubules with surrounding sclerosis; bland, unilayered lining with frequent nuclear indentation of lumina; vesicular chromatin relative to chief cells; attenuated eosinophilic to 'hyper-cleared' cytoplasm; and staining pattern PTH-negative, SOX-10-positive, CK7-positive, GATA-3-positive and PAX-9 dim, a subset with oestrogen/progesterone receptor (ER/PR) positivity. Thirty PTH-negative cysts were identified in the neck/mediastinum; 14 of this group also showed SH. Thirty-two PTH-positive cysts included: 11 cystic parathyroid adenomas, 17 hyperplastic parathyroids, and four carcinomas. KC showed two distinct subtypes and were often found near PTH-negative cysts. PTH-negative cysts were associated with inferior parathyroids, SOX-10 positivity, fibrosclerosis, vesicular nuclei indenting cyst lumina and hyper-cleared or attenuated eosinophilic cytoplasm.

CONCLUSIONS

KC are common in parathyroids and show a distinct histological and immunohistochemical profile, with an inferior predilection favouring branchial cleft III distribution. Diagnostically, the high prevalence of this phenotype in PTH-negative cysts and salivary heterotopia supports derivation of non-functioning cysts from KC. Conversely, PTH-positive cysts are more compatible with cystic change within hyperfunctioning glands.

Cystic parathyroid lesion: case report of rare entity

Introduction and importance

Parathyroid cysts are rarely encountered in neck surgery and often misdiagnosed. We review the case incidence and treatment of parathyroid cystic lesions among all neck procedure in two single institutions operated on by a single surgeon.

Case presentation

We report two female patients presenting with neck swallowing, dysphagia, choking and occasional dysphonia. Ultrasound US (ultrasound) imaging revealed two neck masses of 66 × 44 mm and 44 × 25 × 23 mm; serum iPTH (intact Parathyroid Hormone) levels were 238 and 699 ng/mL respectively and sestamibi scintiscan results were negative for both masses. Intra-cystic fluid evaluation of PTH showed elevated value (>5000 ng/ml). Both patients underwent parathyroidectomy along with total thyroidectomy and thyroid lobectomy. Post-operatively I-PTH and serum calcium levels became normal. Final histology confirmed a benign parathyroid cystic adenoma with concomitant benign thyroid disease.

Clinical discussion

Parathyroid cyst is of rare entity and a diagnostic challenge.

Conclusions

This case report demonstrates that fine needle aspiration (FNA) fluid with intra-cystic parathyroid analysis shows to be fundamental and supports surgery for hyperparathyroidism resolution.

The Parathyroid Gland: An Overall Review of the Hidden Organ for Radiologists

Parathyroid glands are small endocrine glands that regulate calcium metabolism by producing parathyroid hormone (PTH). These are located at the back of the thyroid gland. Typically, four glands comprise the parathyroid glands, although their numbers may vary among individuals. Parathyroid diseases are related to parathyroid gland dysfunction and can be caused by problems with the parathyroid gland itself or abnormal serum calcium levels arising from renal disease. In recent years, as comprehensive health checkups have become more common, abnormal serum calcium levels are often found incidentally in blood tests, after which several additional tests, including a PTH test, ultrasonography (US), technetium-99m sestamibi parathyroid scan, single-photon-emission CT (SPECT)/CT, four-dimensional CT (4D-CT), and PET/CT, are performed for further evaluation. However, the parathyroid gland remains an organ less familiar to radiologists. Therefore, the normal anatomy, pathophysiology, imaging, and clinical findings of the parathyroid gland and its associated diseases are discussed here.

Overview of Thyroid and Parathyroid Disease-The Endocrinology Perspective

Thyroid and parathyroid disorders are quite common in the population and range from benign to malignant conditions that may be hormonally active or inactive. Select disorders of the thyroid and parathyroid can be managed medically, although there are a variety of circumstances that may require definitive management with surgery. Surgical intervention may be required for hormonal control, compressive symptoms, or for the removal and/or control of malignancy. The endocrinologist's perspective of the preoperative and postoperative management regarding thyroid and parathyroid surgeries will be discussed.

Some uncommon cystic lesions in the anterior head and neck region: Pitfalls to be avoided on cytology

Cystic lesions of the anterior head and neck region are a challenging and frequent finding on cytological smears. The scant amount of cellular material in cystic slides poses the greatest difficulty to interpretation, so that frequently they are diagnosed as inadequate or with minimal cellular component. Despite the majority of cystic lesions being benign, a minor portion consist of malignant cystic entities. In these latter cases, the evidence of very scant malignant cells can be misdiagnosed and/or underestimated, leading to a false negative diagnosis. Many papers have already described and detailed the range of possible benign and malignant cystic lesions in head and neck. In the current review we have focused on the less common entities that often lead to serious misinterpretation.

Simultaneous thyroglossal duct cyst with parathyroid cyst: A case report

BACKGROUND

Thyroglossal duct cysts (TDC) are common congenital deformities. Most of them are cysts formed by the thyroglossal ducts that do not disappear and degenerate in the early embryonic stage. TDC exists alone and is rarely complicated by other congenital embryonic malformations. Only a few reports of TDC with branchial cleft cysts, thyroid cancer, thyroid hematoma, and epidermoid cysts have been reported. Therefore, we report a patient with TDC and parathyroid cyst (PC), a rare disease that has never been reported.

CASE SUMMARY

A 47-year-old woman presented to clinic in April 2021 with a neck tumor which she had noticed 5 d earlier. We perfected the relevant examinations, such as ultrasound and computed tomography, and resected the tumor. After surgical treatment, the pathology revealed a cervical thyroglossal duct cyst and a left lobe parathyroid cyst. The patient was followed up for 1 year without significant recurrence.

CONCLUSION

We report a patient with a simultaneous TDC and a PC to explore the correlation between the two congenital anomalies.

Cystic Parathyroid Adenomas as a Risk Factor for Severe Hypercalcemia

(1) Background: Parathyroid cystic adenomas (PCA) are rare entities representing only 0.5-1% of parathyroid adenomas, accounting for 1-2% of cases of primary hyperparathyroidism (PHPT). The purpose of this study was to compare classical and functional/secreting cystic parathyroid lesions and identify risk factors for severe hypercalcemia; (2) Methods: A total of 17 patients with PHPT and parathyroid cysts (study group) were compared with the group of 100 patients with hyperparathyroidism caused by adenoma or hyperplasia (control group). In both groups the majority were women (88% vs. 12%, with gender ratio 7, 3:1). The patients were examined preoperatively and postoperatively: PTH, creatine, calcium and phosphate serum and urine concentrations and calcidiol serum levels were assessed; (3) Results: Patients with parathyroid cyst had statistically higher PTH and calcium serum concentration, higher calciuria and lower serum phosphate concentration. There were no statistically significant differences in the concentration of creatine in serum and urine and tubular reabsorption of phosphorus (TRP); (4) Conclusions: Due to higher PTH and calcium levels, cystic parathyroid adenomas could be one of the rare risk factors for severe hypercalcemia and hypercalcemic crisis which can be life threatening.

Surgical Aspects of Primary Hyperparathyroidism

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

Giant cystic parathyroid adenoma: two case reports and a literature review

An uncommon cause of primary hyperparathyroidism is a cystic parathyroid adenoma. This paper describes two patients with hypercalcemia and right knee disease. Their serum calcium concentration was high, phosphorus concentration was low, and parathyroid hormone (PTH) concentration was high. Ultrasound and computed tomography scans of the neck indicated a cystic mass near the thyroid. Parathyroid scintigraphy showed no focal uptake in one patient and low tracer concentration in the cystic mass in the other patient. Following resection of the cystic masses, both were pathologically confirmed to be a cystic parathyroid adenoma with predominantly cystic degeneration. The calcium and PTH concentrations gradually decreased to the reference range. Both patients were stable at their last follow-up. The diagnosis of a functional cystic parathyroid adenoma is highly challenging because of the different clinical manifestations and negative result on parathyroid tracer scintigraphy. For patients with high serum calcium and PTH concentrations and a cystic mass in the neck, resection of the mass and subsequent postoperative pathological diagnosis is necessary even if the clinical diagnosis of a parathyroid adenoma cannot be confirmed preoperatively. Decreases in the PTH and serum calcium concentrations indicate successful resection of a functional parathyroid adenoma.

Giant Nonfunctioning Parathyroid Cyst: A Case Report and Review of the Literature

Parathyroid cysts are a rare clinical entity that may arise in the neck or mediastinum. They are more common in women and generally present in the fourth and fifth decades of life. Diagnosis of parathyroid cysts is challenging, and despite thorough radiological and cytological investigation, they are often mistaken for thyroid pathology. Definitive diagnosis is often only confirmed following complete surgical resection and histopathological analysis. We present the case of a woman who was referred to our outpatient clinic with a left-sided neck mass and associated compressive symptoms. Initial examination and investigation appeared consistent with a large thyroid nodule. Following surgical resection, the lesion was found to be a parathyroid cyst. Subsequently, we review the available literature on parathyroid cysts with particular emphasis on the diagnostic challenge they pose to clinicians.

Incidentally discovered severe hypercalcaemia from a functioning parathyroid cyst: the limitations of intraoperative parathyroid hormone (IOPTH) monitoring

Parathyroid cysts (PCs) are rare pathologies and are typically non-functional (do not secrete parathyroid hormone (PTH)). The aetiology of PCs is highly debated, and management is complex. We present a unique case of a parathyroid adenoma contained within a functional PC and highlight the limitations of intraoperative PTH monitoring during the surgical resection of functional PCs.

Efficacy of ultrasonography and Tc-99m MIBI SPECT/CT in preoperative localization of parathyroid adenomas causing primary hyperthyroidism

Background

Primary hyperparathyroidism (PHPT) results from an excess of parathyroid hormone (PTH) produced from an overactive parathyroid gland. The study aimed to explore the sonographic features of parathyroid adenomas and assess the diagnostic performance of ultrasonography (US) and Tc-99m MIBI SPECT/CT for preoperative localization of parathyroid adenomas.

Methods

A total of 107 patients were enrolled in this retrospective study who had PHPT and underwent parathyroidectomy. Of the 107 patients, 97 performed US and Tc-99m MIBI SPECT/CT examinations for preoperative localization of parathyroid nodules. The sensitivity and accuracy of each modality were calculated.

Results

In this study, residual parathyroid sign and polar vascular sign were identified as characteristic US features of parathyroid adenomas. These manifestations were closely related to the size of the abnormal parathyroid lesions. Among the 108 parathyroid nodules from 97 patients with PHPT, the sensitivity and accuracy of US for locating the parathyroid nodules were significantly higher than those of Tc-99m MIBI SPECT/CT (93.0% vs. 63.0% and 88.0% vs. 63.0% respectively; ²=26.224, 18.227 respectively, P<0.001). The differences between US+Tc-99m MIBI SPECT/CT and Tc-99m MIBI SPECT/CT-alone were statistically significant (²=33.410, 21.587 respectively, P<0.001), yet there were no significant differences in the sensitivity or accuracy between US+Tc-99m MIBI SPECT/CT and US-alone (²=0.866, 0.187 respectively, P=0.352 and 0.665).

Conclusions

US shows significantly better sensitivity and accuracy for localization of parathyroid adenomas than Tc-99m MIBI SPECT/CT. However, US combined with Tc-99m MIBI SPECT/CT is of great clinical value in the preoperative localization of parathyroid nodules in patients with PHPT.

Parathyroid cyst eclipsed by parathyroid adenoma: Value of adjunct imaging

Parathyroid cyst is a rare clinical entity and often presents as a diagnostic challenge, especially when presents in conjunction with a coexistent parathyroid adenoma. Patient with primary hyperparathyroidism had presented with a localised left inferior parathyroid adenoma with a coexistent right inferior parathyroid cyst which was initially missed on routine ultrasound and sestamibi scan. Suspicion of right inferior thyroid cyst was raised on ultrasound done by a dedicated parathyroid ultrasonologist. Right inferior thyroid cyst was confirmed to be parathyroid cyst on histopathological examination. Parathyroid cysts are seldom picked on sestamibi due to compressed parathyroid tissue present only at the periphery of the cyst. Hence, use of adjunct anatomical imaging like ultrasound, CT scan or MRI is worthwhile to reduce chances of missing hyperfunctional parathyroid tissue, which can eventually lead to revision surgery for persistent primary hyperparathyroidism.

Cystic Parathyroid Adenomas: An Enigmatic Entity and Role of Tc-99 m Sestamibi Scintigraphy

OBJECTIVE

Functional cystic lesion of the parathyroid gland is a rare cause of primary hyperparathyroidism (PHPT). They have been postulated to arise from the hemorrhage and cystic degeneration in the parathyroid adenoma (PA). We intended to analyze their scintigraphic and histopathological findings since available literature is sparse.

METHODS

Dual-phase ^{99 m}Tc-sestamibi planar and SPECT/CT scans performed from January 2014 to January 2020 in patients presenting with PHPT were retrospectively analyzed. The clinical, biochemical, and ultrasound features were collected. Planar and SPECT/CT imaging parameters were analyzed. Detailed histopathological analysis, along with post-surgical clinical and biochemical features of the patients who underwent surgery, was reviewed with a mean follow-up of 21.8 ± 20.1 months.

RESULTS

Of the 979 scans analyzed, 10 showed cystic parathyroid lesions (M:F- 3:7, mean age 45.6 ± 15 years, range: 23-66). The predominant presenting features in patients were abdominal pain and renal stone disease, present in 60% of the patients. On planar scintigraphy, 90% of the patients had tracer avid distinct lesions, whereas tracer activity was seen in the solid part of the cystic lesions in all 10 patients on SPECT/CT, with cystic areas showing an attenuation of 23.1 ± 7.6 HU. Eight of these patients underwent surgery, with all showing PA with cystic changes on histopathology. Two of these patients also showed hemorrhage within the cystic spaces.

CONCLUSION

Hemorrhage within a PA may give rise to cystic parathyroid lesions with PHPT. ^{99 m}Tc-sestamibi scintigraphy with dual-phase imaging and SPECT/CT may help in detecting this rare entity.

Surgical treatment of a functional parathyroid cyst in a patient with primary hyperparathyroidism: A case report

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Parathyroid cysts are a rare endocrine pathology and a difficult diagnostic and therapeutic task.

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The cause of primary hyperparathyroidism in 1–2 % of cases is a functional parathyroid cyst.

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A comprehensive and thorough assessment of all methods of visualization of the parathyroid glands at the preoperative stage, including the use of MSCT angiography and fine-needle aspiration under ultrasound control, is required in order to establish a diagnosis.

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Functional parathyroid cysts require surgical treatment.

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Intraoperative monitoring of iPTH has low sensitivity in relation to the detection and assessment of the radicality of the operation for parathyroid cysts.

Introduction

The frequency of parathyroid cysts in patients with primary hyperparathyroidism is from 1 to 2 %. Nowadays, parathyroid cysts remain a difficult diagnostic and therapeutic task.

Presentation of case

A 57-year-old woman was referred to an endocrine surgeon to evaluate a presence of a mass in the left lateral region of the neck, the appearance of shortness of breath. In the biochemical analysis of the patient's blood, the serum ionized calcium level was increased - 1.53 mmol/l, parathyroid hormone − 149.6 pg/ml. Ultrasound and MSCT scan of the neck showed the presence of a fluid formation measuring 80 × 40 × 33 mm, which was displacing the trachea medially to the right. Fine-needle aspiration revealed the level of iPHT in cystic fluid >2500 pg/mL. The patient underwent cervicotomy, left lower parathyroidectomy with parathyroid cystectomy. According to a histological study, the cyst wall was presented by fibrous tissue, which was lined with epithelium from the dark main cells of the parathyroid gland. Remission of primary hyperparathyroidism was achieved.

Discussion

This clinical report confirms the literature on a decrease in the sensitivity of imaging methods in the diagnosis of parathyroid cysts. A decrease in the effectiveness of intraoperative monitoring of parathyroid hormone with parathyroid cysts was confirmed.

Conclusion

With parathyroid cysts, a comprehensive assessment of all imaging methods is required. Functional parathyroid cysts require surgical treatment. Intraoperative monitoring of iPTH has low sensitivity in relation to the detection and assessment of the radicality of the operation for parathyroid cysts.

Parathyroid cyst: differential diagnosis

Parathyroid cysts are rare lesions of the cervical region and less frequently of the mediastinum. They occur mostly in women and are usually asymptomatic. They generally occur in the fourth and fifth decades of life and mainly are non-functioning. They commonly present as a neck mass that is found incidentally during surgery or in imaging test. Its importance lies in the difficulty in diagnosis, often confusing itself with thyroid pathology. The diagnosis is usually made intraoperatively, confirmed by histopathological examination.The aim of this paper is to report a case of parathyroid cyst that mimics a thyroid nodule.

Parathyroid Cyst: A Case Report of an Uncommon Diagnosis of a Cervical Mass

Parathyroid cysts (PCs) are uncommon entities in clinical practice. The lack of pathognomonic clinical presentation and radiological features of PCs makes preoperative diagnosis unlikely, therefore, most cases are diagnosed intraoperatively or postoperatively at the pathological analysis of the surgical specimen. Treatment of nonfunctional PCs remains controversial and includes fine-needle aspiration, injection of sclerosant, or surgical excision. However, surgical resection still the optimal treatment for functional and larger nonfunctional PCs. We report a case of a 60-year-old female presenting with asymptomatic left-sided cervical swelling diagnosed postoperatively as a nonfunctional PC.

Minimally Invasive Treatment for Benign Parathyroid Lesions: Treatment Efficacy and Safety Based on Nodule Characteristics

OBJECTIVE

This study aimed to evaluate the efficacy and safety of ultrasound (US)-guided minimally invasive treatment in patients with parathyroid lesions.

MATERIALS AND METHODS

This study included 27 patients who had undergone US-guided radiofrequency ablation (RFA) or ethanol ablation (EA) for parathyroid lesions between January 2010 and 2018. RFA was performed in 19 patients with primary hyperparathyroidism (PHPT, n = 11) or secondary hyperparathyroidism (SHPT, n = 8), and EA was performed in eight patients with symptomatic nonfunctioning parathyroid cysts (SNPCs). Nodule size, volume, serum parathyroid hormone (PTH) and calcium levels were recorded before and after treatment. Complications were evaluated during and after treatment.

RESULTS

In patients with PHPT, significant reductions in size and volume were noted after RFA at 6- and 12-month follow-up (all, p < 0.05). Seven nodules nearly completely disappeared (residual volume < 0.1 mL); serum PTH and calcium levels were reduced to normal ranges (7/11, 63.6%). Four patients experienced partial reductions of serum PTH and calcium levels (4/11, 36.4%). In patients with SHPT, three experienced therapeutic response of serum PTH (3/8, 37.5%), while five showed persistent hyperparathyroidism (5/8, 62.5%) within 6 months after RFA. In patients with SNPCs, EA resulted in significant reductions in cyst size and volume (all, p < 0.05) at the last follow-up. A total of four complications (two transient hypocalcemia [RFA], one permanent [RFA], and one transient [EA] hoarseness) were observed.

CONCLUSION

Minimally invasive treatments, such as RFA and EA, may serve as therapeutic alternatives for patients with PHPT or SNPCs; they may have limited usefulness in patients with SHPT.

A Functional Parathyroid Cyst from the Hemorrhagic Degeneration of a Parathyroid Adenoma

A 77-year-old man with a history of hypertension, prostate hyperplasia, and urolithiasis was admitted for acute kidney injury caused by hypercalcemia. Neck ultrasonography showed a large cyst adjacent to the right lower thyroid lobe. Although a ^99mtechnetium sestamibi scan was negative, an extremely high intracystic intact parathyroid hormone level suggested that the cyst had a parathyroid origin and that a functional parathyroid cyst was present. Immunohistochemical staining for the calcium-sensing receptor (CaSR) after right lower parathyroidectomy revealed CaSR-positive cells lining the cyst, indicating that the functional parathyroid cyst had originated from the hemorrhagic degeneration of a parathyroid adenoma.

Early and late adverse renal effects after potentially nephrotoxic treatment for childhood cancer

BACKGROUND

Improvements in diagnostics and treatment for paediatric malignancies resulted in a major increase in survival. However, childhood cancer survivors (CCS) are at risk of developing adverse effects caused by multimodal treatment for their malignancy. Nephrotoxicity is a known side effect of several treatments, including cisplatin, carboplatin, ifosfamide, radiotherapy and nephrectomy, and can cause glomerular filtration rate (GFR) impairment, proteinuria, tubulopathy, and hypertension. Evidence about the long-term effects of these treatments on renal function remains inconclusive. It is important to know the risk of, and risk factors for, early and late adverse renal effects, so that ultimately treatment and screening protocols can be adjusted. This review is an update of a previously published Cochrane Review.

OBJECTIVES

To evaluate existing evidence on the effects of potentially nephrotoxic treatment modalities on the prevalence of renal dysfunction in survivors treated for childhood cancer with a median or mean survival of at least one year after cessation of treatment, where possible in comparison with the general population or CCS treated without potentially nephrotoxic treatment. In addition, to evaluate evidence on associated risk factors, such as follow-up duration, age at time of diagnosis and treatment combinations, as well as the effect of doses.

SEARCH METHODS

On 31 March 2017 we searched the following electronic databases: CENTRAL, MEDLINE and Embase. In addition, we screened reference lists of relevant studies and we searched the congress proceedings of the International Society of Pediatric Oncology (SIOP) and The American Society of Pediatric Hematology/Oncology (ASPHO) from 2010 to 2016/2017.

SELECTION CRITERIA

Except for case reports, case series and studies including fewer than 20 participants, we included studies with all study designs that reported on renal function (one year or longer after cessation of treatment), in CCS treated before the age of 21 years with cisplatin, carboplatin, ifosfamide, radiation involving the kidney region, a nephrectomy, or a combination of two or more of these treatments. When not all treatment modalities were described or the study group of interest was unclear, a study was not eligible for the evaluation of prevalence. We still included it for the assessment of risk factors if it had performed a multivariable analysis.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, 'Risk of bias' assessment and data extraction using standardised data collection forms. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

Apart from the remaining 37 studies included from the original review, the search resulted in the inclusion of 24 new studies. In total, we included 61 studies; 46 for prevalence, six for both prevalence and risk factors, and nine not meeting the inclusion criteria, but assessing risk factors. The 52 studies evaluating the prevalence of renal dysfunction included 13,327 participants of interest, of whom at least 4499 underwent renal function testing. The prevalence of adverse renal effects ranged from 0% to 84%. This variation may be due to diversity of included malignancies, received treatments, reported outcome measures, follow-up duration and the methodological quality of available evidence.Seven out of 52 studies, including 244 participants, reported the prevalence of chronic kidney disease, which ranged from 2.4% to 32%.Of these 52 studies, 36 studied a decreased (estimated) GFR, including at least 432 CCS, and found it was present in 0% to 73.7% of participants. One eligible study reported an increased risk of glomerular dysfunction after concomitant treatment with aminoglycosides and vancomycin in CCS receiving total body irradiation (TBI). Four non-eligible studies assessing a total cohort of CCS, found nephrectomy and (high-dose (HD)) ifosfamide as risk factors for decreased GFR. The majority also reported cisplatin as a risk factor. In addition, two non-eligible studies showed an association of a longer follow-up period with glomerular dysfunction.Twenty-two out of 52 studies, including 851 participants, studied proteinuria, which was present in 3.5% to 84% of participants. Risk factors, analysed by three non-eligible studies, included HD cisplatin, (HD) ifosfamide, TBI, and a combination of nephrectomy and abdominal radiotherapy. However, studies were contradictory and incomparable.Eleven out of 52 studies assessed hypophosphataemia or tubular phosphate reabsorption (TPR), or both. Prevalence ranged between 0% and 36.8% for hypophosphataemia in 287 participants, and from 0% to 62.5% for impaired TPR in 246 participants. One non-eligible study investigated risk factors for hypophosphataemia, but could not find any association.Four out of 52 studies, including 128 CCS, assessed the prevalence of hypomagnesaemia, which ranged between 13.2% and 28.6%. Both non-eligible studies investigating risk factors identified cisplatin as a risk factor. Carboplatin, nephrectomy and follow-up time were other reported risk factors.The prevalence of hypertension ranged from 0% to 50% in 2464 participants (30/52 studies). Risk factors reported by one eligible study were older age at screening and abdominal radiotherapy. A non-eligible study also found long follow-up time as risk factor. Three non-eligible studies showed that a higher body mass index increased the risk of hypertension. Treatment-related risk factors were abdominal radiotherapy and TBI, but studies were inconsistent.Because of the profound heterogeneity of the studies, it was not possible to perform meta-analyses. Risk of bias was present in all studies.

AUTHORS' CONCLUSIONS

The prevalence of adverse renal effects after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region, nephrectomy, or any combination of these, ranged from 0% to 84% depending on the study population, received treatment combination, reported outcome measure, follow-up duration and methodological quality. With currently available evidence, it was not possible to draw solid conclusions regarding the prevalence of, and treatment-related risk factors for, specific adverse renal effects. Future studies should focus on adequate study designs and reporting, including large prospective cohort studies with adequate control groups when possible. In addition, these studies should deploy multivariable risk factor analyses to correct for possible confounding. Next to research concerning known nephrotoxic therapies, exploring nephrotoxicity after new therapeutic agents is advised for future studies. Until more evidence becomes available, CCS should preferably be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

Coexistence of a large functioning parathyroid cyst with papillary thyroid carcinoma: A case report and review of the literature

Parathyroid cysts constitute a rare cause of primary hyperparathyroidism (PHPT). PHPT may also rarely coexist with non-medullary thyroid carcinoma (NMTC). We describe a case of a 70-year-old woman who was diagnosed with PHPT, on the occasion of nephrolithiasis (corrected calcium and PTH levels: 10.8 mg/dl and 187 pg/ml, respectively). Ultrasonographic and scintigraphic investigation confirmed the diagnosis of a large parathyroid cyst attached to the lower pole of the right thyroid lobe and, consequently, the patient underwent parathyroidectomy. Due to the coexistence of multinodular goitre, with some nodules characterized as suspicious of malignancy, a total thyroidectomy was also performed. A histological diagnosis of cystic parathyroid adenoma was made. A unifocal papillary thyroid carcinoma of follicular subtype, 6 mm in diameter, was also detected. The patient's post-surgical course was uneventful and she remained normocalcaemic two years later. PHPT may rarely coexist with papillary thyroid carcinoma (PTC). The pathogenetic mechanisms linking these two endocrine entities are currently unknown.

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Parathyroid cysts constitute a rare cause of primary hyperparathyroidism (PHPT).

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Primary hyperparathyroidism may also rarely coexist with non-medullary thyroid carcinoma.

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The pathogenetic mechanisms linking these two endocrine entities are currently unknown.

Parathyroid cysts: A review of 359 patients reported in the international literature

BACKGROUND

Parathyroid cysts are lesions that represent 1-5% of neck masses. They are subdivided into two categories: functioning and non-functioning.The aim of the present review is to give a detailed account of all reported cases of parathyroid cysts in the literature and to analyze statistically the available data.

METHODS

A bibliographic research was performed from 1905 until 2016. A database with the patients' characteristics was made and analyzed statistically.

RESULTS

A total of 218 articles were found, reporting 359 cases of cysts. Mean age of patients was 49.24 y/o and the male/female ratio was 1:1.85. The most common locations were left thyroid lobe (113/358 patients, 31.6%), and superior mediastinum (69/358 patients, 19.3%), while the most common symptoms were neck mass (148/355 patients, 41.7%), compressive symptoms (73/355 patients, 206%) and hyperparathyroidism (62/355 patients, 17.5%). Non-functioning cysts were more frequent (220/357 patients, 61.6%). Regarding dimensions, mean diameter was 4.88 cm. Ultrasound and FNA are used for their diagnosis, while cystic fluid analysis may help the differential diagnosis. Recurrences were mentioned in 27/97 patients (27.8%) with available data. No deaths due to parathyroid cysts were mentioned in the literature.

CONCLUSION

Parathyroid cysts should be taken into consideration in case of parathyroid dysfunction or asymptomatic neck mass. The surgeon's careful manipulations on the cyst are crucial for a definitive treatment.

18F-Fluorocholine-Positron Emission Tomography/Computerised Tomography is Useful in Localising 99mTc-Sesta-methoxyisobutylisonitrile-Negative Parathyroid Cyst Causing Normocalcemic Primary Hyperparathyroidism

Parathyroid cysts are extremely rare and are rarely associated with primary hyperparathyroidism (PHPT), which are difficult to localise, as they are ^99mTc-sesta-methoxyisobutylisonitrile (sestaMIBI) negative. We report for the first time the utility of ¹⁸F-fluorocholinepositron emission tomography/computerised tomography (PC-PET/CT) in localising parathyroid cyst causing normocalcemic PHPT. A 76-year-old lady with progressively worsening osteoporosis from 2014–2017 (in spite of annual zolendronic acid infusions, daily calcium and vitamin-D supplementation) with persistently normal serum calcium and vitamin D, but elevated parathyroid hormone, had normal sestaMIBI scans of the neck on multiple occasions. FC-PET/CT finally revealed soft tissue uptake, suggestive of right superior parathyroid adenoma/ hyperplasia. Surgical removal of the culprit lesion resulted in resolution of hyperparathyroidism, histopathologic evaluation of which revealed a cystic lesion lined by chief cell variant parathyroid cells without any nuclear atypia, capsular or vascular invasion. FC-PET/CT is useful in localising culprit parathyroid lesions, especially when they are sestaMIBI negative. PC-PET/CT is useful in localising parathyroid hyperplasia and ectopic parathyroids, which are frequently missed by sestaMIBI. There is an urgent need for comparative studies between sestaMIBI and FC-PET/CT in PHPT. We report for the first time the usefulness of FC-PET/CT in localising sestaMIBI-negative functional parathyroid cyst causing normocalcemic PHPT.

The Clinical Features of Cystic Parathyroid Adenoma in Chinese Population: A Single-Center Experience

OBJECTIVE

Cystic parathyroid adenoma is a rare cause of primary hyperparathyroidism, but its preoperative diagnosis and management remain inconclusive.

METHOD

We retrospectively identified patients with cystic parathyroid adenomas who underwent surgery at Peking Union Medical College Hospital.

RESULTS

Patients with cystic parathyroid adenomas had higher serum intact parathyroid hormone and calcium levels, larger maximum tumor diameter, and lower serum inorganic phosphorus level than did those with solid adenomas. Patients with cystic adenomas were predominantly male, and hypercalcemic crisis and atypical adenomas were common. The accuracy of preoperative localization methodologies was lower in patients with cystic adenomas than in patients with solid adenomas. US-guided fine-needle aspiration was performed in 11 patients. In all patients, the iPTH level in cystic fluid was much higher than that in serum. No sign of recurrence was observed after a median follow-up of 39 months.

CONCLUSIONS

Cystic parathyroid adenomas may not be as rare as previously reported. FNA may be a safe and feasible localization methodology for patients with inconclusive preoperative localization methodologies. Close follow-up is necessary for patients with cystic parathyroid adenomas, which account for a substantial proportion of atypical adenoma cases.

Non-functioning parathyroid cystic tumour: malignant or not? Report of a case

Parathyroid carcinoma (PC) is a very rare endocrine tumour, usually characterized by symptoms such as a neck mass, dysphonia, severe hypercalcemia exceeding 140 mg/L and elevated serum parathyroid hormone levels, even more than 5 times the upper limit of normal. Non-functioning parathyroid cancer is extremely rare and, in this case, its pre-operative diagnosis is often difficult. A 54-year old female patient, referring dysphagia and dysphonia, underwent neck ultrasound and neck CT. A left thyroid nodule, probably cystic, was found. It presented caudal extent on anterior mediastinum causing compression of the left lateral wall of the trachea. The preoperative calcemia was into the normal range. The patient underwent left thyroid lobectomy. Histological exam showed a cystic lesion, immunohistochemically originating from parathyroid that oriented for carcinoma. The 18 months follow-up did not show a residual-recurrent disease. The parathyroid origin of a neck lesion could not be suspected before surgery when specific laboratory tests are not available and clinical effects of hyperparathyroidism syndrome are not present. Histological features are not always sufficient for the differential diagnosis between the parathyroid adenoma and carcinoma. The immunohistochemistry is an useful tool that can aid to reach the definite diagnosis.

Intrathyroidal Parathyroid Cyst: An Unusual Neck Mass

Parathyroid cyst (PC) is a very rare condition. A case of intrathyroidal PC is being reported here in a 53-year-old woman who presented to the endocrine clinic with slowly progressive painless left anterior neck swelling for 1 year with no symptoms of thyroid or parathyroid dysfunction and no compressive symptoms. Ultrasound of the thyroid showed a well-defined cystic lesion measuring 4.7 × 3.6 cm in maximum diameter with internal echoes within the cyst located in the left lobe of the thyroid gland. Fine needle aspiration revealed colorless clear fluid with a high concentration of parathyroid hormone. The patient underwent left hemithyroidectomy at her request. Histopathology revealed parathyroid tissue with unilocular cyst and thyroid tissue with goitrous changes. She was in remission, and there was no evidence of thyroid or parathyroid dysfunction after surgery.

Small nonfunctional parathyroid cysts: single institution experience

Parathyroid cysts (PCs) account for less than 1% of all parathyroid lesions and are most commonly located along thyroid lobes, rarely at ectopic sites. PCs are important because they can pose a differential diagnostic challenge against other cystic formations of the neck. PCs can be functional (elevated serum parathyroid hormone level) and nonfunctional. Four cases of nonfunctional PCs are presented. All four female patients underwent physical examination and ultrasonography of the neck with ultrasound-guided fine-needle aspiration biopsy (UG-FNA). The material thus obtained was stained by the standard May-Grünwald-Giemsa method. Parathyroid hormone level was determined in aspirate and serum, along with serum levels of total calcium, inorganic phosphates. In two asymptomatic patients, remission occurred after initial aspiration biopsy; one patient had compression syndrome with vocal cord paresis that required surgical treatment; and one patient had cyst recurrence that was surgically removed. Cystic neck masses can pose a major differential diagnostic problem considering different approach, treatment method, and preoperative and postoperative follow up. Surgical treatment is necessary in case of functional and large nonfunctional PCs (due to compression syndrome), whereas individualized therapeutic approach is used in case of small nonfunctional PCs. Ultrasonography with UG-FNA, cytologic analysis of the material obtained, and determination of parathyroid hormone level in aspirate and serum are crucial for making an accurate diagnosis.

Parathyroid cysts: the Latin-American experience

BACKGROUND

Parathyroid cyst is an infrequent and unsuspected disease. There are more than 300 hundred cases reported in the world literature, a few of them are from Latin America. The experience of our centers and a review of the cases are presented.

METHODS

Case report of a series of patients with parathyroid cyst from our institutions according to the CARE guidelines (Case Reports). A search of Medline, Embase, BIREME (Biblioteca Regional de Medicina) LILACS (Literatura Latinoamericana y del Caribe en Ciencias de la Salud), Google Scholar and Scielo (Scientific Electronic Library on Line) databases and telephonic or email communications with other experts from Latin-America was performed .

RESULTS

Six patients with parathyroid cyst were found in our centers in Colombia. Most of them were managed with aspiration of the cyst. Two of them required surgery. Only one case was functional. Twelve reports from Latin America were found for a total of 18 cases in our region adding ours.

CONCLUSIONS

Parathyroid cysts are uncommonly reported in Latin America. Most of them are diagnosed postoperatively. Suspicion for parathyroid cyst should be raised when a crystal clear fluid is aspirated from a cyst. The confirmation of the diagnosis may be easily done if parathyroid hormone (PTH) level is measured in the cyst fluid.

Cystic parathyroid glands in MEN1: A rare entity?

Approximately 300 cases of sporadic parathyroid cyst (PCs) have been reported to date. Only two cases have been described in MEN1 so far. Detection by imaging could be challenging, especially in multiglandular primary hyperparathyroidism (HPT) and clinical outcome could be different. During the period 1990-2014, 71 MEN1 patients were operated for primary hyperparathyroidism in our centre. We report three cases of PCs in MEN1 patients affected by HPT, who underwent a total or subtotal parathyroidectomy with transcervical thymectomy. In our series, all three patients had an unsatisfactory postoperative course, at variance with the high percentage (over 90 %) of long-term success in MEN1 patients operated at our centre. One patient affected by cystic degeneration of all the four parathyroid glands reported persistent hypoparathyroidism, despite autografts of parathyroid tissue. For the other two cases, surgery failed to cure hyperparathyroidism, perhaps because of the presence of undetected ectopic parathyroid tissue. In the context of a multiglandular disease such as MEN1 syndrome, PCs seem rare but our experience shows about a 4 % incidence. Furthermore their presence, even in expert hands, could affect the preoperative identification of the parathyroid glands due to the difficult differential diagnosis between PC and other cystic lesions of the neck, and intraoperative detection of the glands as well as the postoperative outcome.

PRIMARY HYPERPARATHYROIDISM: COMPARING BETWEEN SOLID AND CYSTIC ADENOMAS AND THE EFFICACY OF ULTRASOUND AND SINGLE-PHOTON EMISSION COMPUTED TOMOGRAPHY IN THEIR DIAGNOSIS

OBJECTIVE

Primary hyperparathyroidism (PHPT) is a disorder that results from abnormal functioning of the parathyroid glands. The purpose of this study was to compare cystic and solid adenomas by analyzing different variables associated with PHPT and parathyroid adenomas (age, calcium, phosphorus, and parathyroid hormone [PTH] levels, adenoma volume) while comparing the efficacy of ultrasound and single-photon emission computed tomography in differentiating between both types of adenoma.

METHODS

From 152 patients diagnosed with PHPT between January 2013 and 2014, only 109 patients who had positive ultrasonographic findings for single parathyroid adenoma were included in the study.

RESULTS

A total of 26 patients had cystic adenomas and 83 patients had solid adenomas. Sestamibi (MIBI) was negative in 50% of the cystic adenoma group and 27.7% of the solid adenoma group, with an overall technetium-MIBI efficacy of 67%. Age, phosphorus level, and adenoma volume were significantly higher in patients with cystic adenomas (P = .001, P = .02, and P = .02, respectively), whereas calcium and PTH levels were significantly higher in patients with solid adenomas (P = .02, P = .038, respectively). MIBI had a significant correlation with PTH levels (P = .031) and adenoma volume (P = .05) only in patients with solid adenomas. No significant correlation was found between sex and type of parathyroid adenoma.

CONCLUSION

The current study is the first to compare age, PTH levels, and adenoma volume between cystic and solid adenoma patients, providing more information for the poorly understood pathology of cystic adenomas. Our findings showed that age and calcium and PTH levels are significantly higher in patients with solid adenomas, whereas adenoma volume and phosphorus levels are significantly higher in patients with cystic adenomas.

Parathyroid ultrasonography: the evolving role of the radiologist

Previously, radiologists played a limited role in the treatment of parathyroid disease, primary focusing on the preoperative localization of parathyroid lesions responsible for hyperparathyroidism. But, the widespread use of high-resolution ultrasound has lead to the increasing detection of parathyroid incidentalomas (PTIs). Consequently, radiologists may be required to differentiate PTIs from thyroid lesions, which is most reliably accomplished through the fine needle aspiration-parathyroid hormone analysis. Various nonsurgical treatment modalities for hyperfunctioning parathyroid lesions have been developed with some efficacy. Especially for symptomatic nonfunctioning parathyroid cysts, simple aspiration is a first-line procedure for diagnosis and treatment, while ethanol ablation is a subsequent treatment modality for recurrent cases.

An Unusual Neck Mass: A Case of a Parathyroid Cyst and Review of the Literature

Parathyroid cysts (PC) are an unusual cause of neck swellings. The majority are nonfunctioning and prove to be a diagnostic challenge given their nonspecific physical and radiological characteristics. This is compounded by their rare occurrence, leading them to be overlooked in the differential diagnosis of neck lumps. Imaging techniques fail to determine the origin of these lesions, but a preoperative diagnosis can be achieved by fine-needle aspiration and measurement of cystic fluid C-terminal parathyroid hormone levels. Treatment of nonfunctioning cysts remains controversial and includes needle aspiration, injection of sclerosant, or surgical excision. We present a case of a 44-year-old female presenting with an asymptomatic anterior neck swelling, diagnosed postoperatively as a parathyroid cyst.

Functional parathyroid cyst in a patient with systemic lupus erythematosus: a case report

Functional parathyroid cysts are a rare cause of primary hyperparathyroidism and are often mistaken for thyroid cysts. Systemic lupus erythematosus (SLE) is also a very rare cause of hypercalcemia. We report the case of a 62-year-old woman, who was diagnosed with SLE 30 years ago, presenting with clinical and biochemical features of primary hyperparathyroidism. Laboratory investigation revealed increased serum calcium and parathyroid hormone (PTH) levels; neck ultrasonography (USG) revealed 40×34×26 mm cystic mass in the left lobe of thyroid gland. PTH level in the cysts was >2500 pg/ml, determined by USG-guided fine-needle aspiration (FNA). In this case, no evidence for potential pathogenic association between parathyroid cyst and SLE was uncovered. However, the recognition of this association is very important because the therapeutical strategy is completely different. Operative management is usually straightforward and alleviates symptoms and any biochemical abnormalities caused by the cyst.

A Case of Primary Hyperparathyroidism due to Intrathyroidal Parathyroid Cyst

Parathyroid cysts constitute 0.08–3.41% of all parathyroid masses. Intrathyroidal parathyroid cysts, however, are rare conditions with only a few cases being reported. Most of the parathyroid cysts are found to be nonfunctional and functional cysts are generally thought to be due to cystic degeneration of parathyroid adenomas. A cystic, smooth contoured lesion of 24 × 19 × 16 mm was observed in left thyroid lobe of a 76-year-old woman during ultrasonography which was performed as routine workup for primary hyperparathyroidism. It was defined as a cystic thyroid nodule at first. Tc^99m sestamibi scintigraphy was performed to see any parathyroid lesions, but no radioactive uptake was observed. Intact parathormone (iPTH) level was found to be >600 pg/mL in cyst aspiration fluid. Left lobectomy was performed, with a diagnosis of primary hyperparathyroidism due to functional parathyroid cyst. Serum iPTH level was decreased >50% postoperatively and histopathological evaluation was consistent with an encapsulated parathyroid adenoma with a cystic center. Parathyroid cysts are among rare causes of primary hyperparathyroidism. Diagnosis is made by markedly increased iPTH level in cyst fluid and observation of parathyroid epithelium lining the cyst wall.

Parathyroid: The Pathology of Hyperparathyroidism

This review focuses on the pathologic entities associated with hyperparathyroidism in humans. A discussion of the lesions, their embryology, and pathologic features is included. Immunohistology, cytopathology, and a brief overview of molecular aspects of the lesion are included.

Early and late renal adverse effects after potentially nephrotoxic treatment for childhood cancer

BACKGROUND

Great improvements in diagnostics and treatment for malignant disease in childhood have led to a major increase in survival. However, childhood cancer survivors (CCS) are at great risk for developing adverse effects caused by multimodal treatment for their malignancy. Nephrotoxicity is one of these known (acute) side effects of several treatments, including cisplatin, carboplatin, ifosfamide, radiotherapy and nephrectomy, and can cause glomerular filtration rate impairment, proteinuria, tubulopathy and hypertension. However, evidence about the long-term effects of these treatments on renal function remains inconclusive. To reduce the number of (long-term) nephrotoxic events in CCS, it is important to know the risk of, and risk factors for, early and late renal adverse effects, so that ultimately treatment and screening protocols can be adjusted.

OBJECTIVES

To evaluate existing evidence on the effects of potentially nephrotoxic treatment modalities on the prevalence of and associated risk factors for renal dysfunction in survivors treated for childhood cancer with a median or mean survival of at least one year after cessation of treatment, where possible in comparison with healthy controls or CCS treated without potentially nephrotoxic treatment.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2011), MEDLINE/PubMed (from 1945 to December 2011) and EMBASE/Ovid (from 1980 to December 2011).

SELECTION CRITERIA

With the exception of case reports, case series and studies including fewer than 20 participants, we included studies with all study designs that reported on renal function (one year or longer after cessation of treatment) in children and adults who were treated for a paediatric malignancy (aged 18 years or younger at diagnosis) with cisplatin, carboplatin, ifosfamide, radiation including the kidney region and/or a nephrectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment and data extraction using standardised data collection forms. Analyses were performed according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

The search strategy identified 5504 studies, of which 5138 were excluded on the basis of title and/or abstract. The full-text screening of the remaining 366 articles resulted in the inclusion of 57 studies investigating the prevalence of and sometimes also risk factors for early and late renal adverse effects of treatment for childhood cancer. The 57 studies included at least 13,338 participants of interest for this study, of whom at least 6516 underwent renal function testing. The prevalence of renal adverse effects ranged from 0% to 84%. This variation may be due to diversity in included malignancies, prescribed treatments, reported outcome measurements and the methodological quality of available evidence.Chronic kidney disease/renal insufficiency (as defined by the authors of the original studies) was reported in 10 of 57 studies. The prevalence of chronic kidney disease ranged between 0.5% and 70.4% in the 10 studies and between 0.5% and 18.8% in the six studies that specifically investigated Wilms' tumour survivors treated with a unilateral nephrectomy.A decreased (estimated) glomerular filtration rate was present in 0% to 50% of all assessed survivors (32/57 studies). Total body irradiation; concomitant treatment with aminoglycosides, vancomycin, amphotericin B or cyclosporin A; older age at treatment and longer interval from therapy to follow-up were significant risk factors reported in multivariate analyses. Proteinuria was present in 0% to 84% of all survivors (17/57 studies). No study performed multivariate analysis to assess risk factors for proteinuria.Hypophosphataemia was assessed in seven studies. Reported prevalences ranged between 0% and 47.6%, but four of seven studies found a prevalence of 0%. No studies assessed risk factors for hypophosphataemia using multivariate analysis. The prevalence of impairment of tubular phosphate reabsorption was mostly higher (range 0% to 62.5%; 11/57 studies). Higher cumulative ifosfamide dose, concomitant cisplatin treatment, nephrectomy and longer follow-up duration were significant risk factors for impaired tubular phosphate reabsorption in multivariate analyses.Treatment with cisplatin and carboplatin was associated with a significantly lower serum magnesium level in multivariate analysis, and the prevalence of hypomagnesaemia ranged between 0% and 37.5% in the eight studies investigating serum magnesium.Hypertension was investigated in 24 of the 57 studies. Reported prevalences ranged from 0% to 18.2%. A higher body mass index was the only significant risk factor noted in more than one multivariate analysis. Other reported factors that significantly increased the risk of hypertension were use of total body irradiation, abdominal irradiation, acute kidney injury, unrelated or autologous stem cell donor type, growth hormone therapy and older age at screening. Previous infection with hepatitis C significantly decreased the risk of hypertension.Because of the profound heterogeneity of the studies, it was not possible to perform any meta-analysis.

AUTHORS' CONCLUSIONS

The prevalence of renal adverse events after treatment with cisplatin, carboplatin, ifosfamide, radiation therapy involving the kidney region and/or nephrectomy ranged from 0% to 84%. With currently available evidence, it was not possible to draw any conclusions with regard to prevalence of and risk factors for renal adverse effects. Future studies should focus on adequate study design and reporting and should deploy multivariate risk factor analysis to correct for possible confounding. Until more evidence becomes available, CCS should be enrolled into long-term follow-up programmes to monitor their renal function and blood pressure.

A case report: Giant cystic parathyroid adenoma presenting with parathyroid crisis after Vitamin D replacement

BACKGROUND

Parathyroid adenoma with cystic degeneration is a rare cause of primary hyperparathyroidism. The clinical and biochemical presentation may mimic parathyroid carcinoma.

CASE PRESENTATION

We report the case of a 55 year old lady, who had longstanding history of depression and acid peptic disease. Serum calcium eight months prior to presentation was slightly high, but she was never worked up. She was found to be Vitamin D deficient while being investigated for generalized body aches. A month after she was replaced with Vitamin D, she presented to us with parathyroid crisis. Her corrected serum calcium was 23.0 mg/dL. She had severe gastrointestinal symptoms and acute kidney injury. She had unexplained consistent hypokalemia until surgery. Neck ultrasound and CT scan revealed giant parathyroid cyst extending into the mediastinum. After initial medical management for parathyroid crisis, parathyroid cystic adenoma was surgically excised. Her serum calcium, intact parathyroid hormone, creatinine and potassium levels normalized after surgery.

CONCLUSION

This case of parathyroid crisis, with very high serum calcium and parathyroid hormone levels, is a rare presentation of parathyroid adenoma with cystic degeneration. This case also highlights that Vitamin D replacement may unmask subclinical hyperparathyroidism. Consistent hypokalemia until surgery merits research into its association with hypercalcemia.

Parathyroid cyst: the forgotten diagnosis of a neck mass

The differential diagnosis of cystic cervical masses includes cystic thyroid disease or some embryological diseases. Parathyroid cyst is one of the less common causes of the cervical masses. The Swedish anatomist Sandstrom reported the first description of parathyroid cyst in 1880. Up to date, only about 300 cases have been reported in the world literature. They may be functional or nonfunctional, depending on the presence or absence of the hyperparathyroidism and treatment options vary for both presentations. Particularly, nonfunctional cysts are often considered as thyroid cysts. Diagnosis is best made by monitoring serum calcium levels and sending cyst fluid for parathormone analysis. We herein report a patient diagnosed with a parathyroid cyst who had received the diagnosis of goitre at other institute; including a review of the literature.

Cystic parathyroid adenoma: sonographic features and correlation with 99mTc-sestamibi SPECT findings

OBJECTIVE

The purpose of this study was to describe the typical ultrasound features of cystic parathyroid adenoma.

MATERIALS AND METHODS

A review of a surgical database and electronic medical records from 2006 to 2009 identified the cases of 15 patients who underwent preoperative cervical sonography for primary hyperparathyroidism with subsequent resection of pathologically proven parathyroid adenoma with predominantly cystic components. Two radiologists retrospectively evaluated the preoperative ultrasound images and assessed for cyst complexity, size, location, and color Doppler vascularity. Technetium-99m-sestamibi SPECT findings, surgical and pathologic reports, and the results of parathyroid hormone assay of the cyst fluid also were reviewed.

RESULTS

Most of the cystic adenomas (14/15, 93%) were deep or inferolateral to the adjacent thyroid. The same percentage were elongated and had peripheral nodular components. An echogenic border separating the adenoma from the overlying thyroid was identified in 9 of 15 patients (60%). Color Doppler examination of 14 patients showed feeding vessels with internal color flow to the solid components in 10 patients (71%). Six of 14 patients underwent preoperative or intraoperative sampling of cyst fluid, and the assay showed the parathyroid hormone levels ranged from 1,198 to greater than 5,000 pg/mL. Fourteen of 15 patients underwent preoperative sestamibi SPECT, and the adenoma was definitively localized in four patients (29%). The accuracy of preoperative localization improved to 79% (11/14) when sestamibi SPECT scans were interpreted in correlation with cervical ultrasound images.

CONCLUSION

Awareness of typical sonographic features (location, color Doppler vascularity) may aid radiologists in preoperative localization of parathyroid adenomas, even when cystic degeneration occurs. In cases in which imaging or clinical features are equivocal, the results of cyst fluid sampling and parathyroid hormone assay are confirmatory.

Nonfunctional parathyroid cyst: case report

CONTEXT

Parathyroid cysts are rare clinical and pathological entities, with less than 300 cases reported. The inferior parathyroid glands are most commonly involved, with left-side predominance. Parathyroid cysts may be functional or nonfunctional, depending on their association with hypercalcemia.

CASE REPORT

A 25-year-old man presented a palpable asymptomatic left-side neck mass. Ultrasound revealed a cystic structure contiguous with the left thyroid lobe. Serum ionic calcium was normal. The patient underwent left thyroid lobectomy plus isthmectomy with excision of the cyst. The histological findings revealed a parathyroid cyst. Parathyroid cysts typically present as asymptomatic neck masses, and surgical excision appears to be the treatment of choice.