An Unusual Case of Recurrent Hyperparathyroidism and Papillary Thyroid Cancer

ObjectiveTo report an unusual occurrence of recurrent hyperparathyroidism due to papillary thyroid carcinoma.MethodsWe describe the clinical history, physical examination findings, laboratory values, imaging findings, and pathologic findings of a woman who developed recurrent hyperparathyroidism 13 years after successful parathyroidectomy.ResultsA 59-year-old woman presented to our clinic with recurrent primary hyperparathyroidism. In 1994, she presented with nephrolithiasis and underwent resection of a right superior parathyroid adenoma that resulted in clinical and biochemical cure. Her clinical course had been followed at periodic intervals, and she had been symptom-free and normocalcemic. In 2007, she again developed nephrolithiasis and was documented to have recurrent hyperparathyroidism. Imaging studies suggested a parathyroid adenoma near the right inferior pole of the thyroid. The patient had reoperative neck exploration. No obvious parathyroid adenoma was found and a right thyroid lobectomy was performed, which resulted in normalization of intraoperative intact parathyroid hormone levels, and the incision was closed. Final pathology demonstrated no parathyroid adenoma, but instead, a 1-cm papillary thyroid carcinoma that stained positive for parathyroid hormone. More than 6 months after surgery, she remains clinically and biochemically cured.ConclusionsRecurrent hyperparathyroidism occurs secondary to multiple causes. This case demonstrates the challenge a surgeon faces in managing recurrent disease and highlights a rare phenomenon of papillary thyroid cancer causing recurrent hyperparathyroidism. (Endocr Pract. 2009;15:349-352)     

Utility of Ultrasound-Guided Fine-Needle Aspiration of Parathyroid Adenomas for Localization Before Minimally Invasive Parathyroidectomy

ObjectiveTo determine the sensitivity and specificity of ultrasound (US)-guided fine-needle aspiration (FNA) and measurement of parathyroid hormone (PTH) in the aspirate (FNA/PTH) as a preoperative localization procedure.MethodsThe study group consisted of 34 consecutive patients with primary hyperparathyroidism. The FNA/PTH estimations in these patients were compared with those from 13 proven thyroid nodules. All patients underwent US study of the neck, which suggested the presence of a solitary adenoma in 30 patients and of hyperplasia in 2; no adenoma or hyperplasia could be visualized in 2 patients. Thirty-two patients underwent FNA/PTH, which yielded a mean PTH level of 22,060.0 ± 6,653.0 pg/mL. This result was significantly different (P < 0.001) from the mean PTH level in 13 thyroid nodules (9.0 ± 1.0 pg/mL).ResultsOn the basis of the FNA/PTH results, 28 patients with suspected adenomas underwent minimally invasive parathyroidectomy (MIP), and 2 patients are awaiting a surgical procedure. Of these 28 patients, 27 had more than a 50% decline in intraoperative PTH level after removal of the suspected adenoma, confirming surgical success. In 1 patient, multigland hyperplasia was discovered during the operation. The 2 study subjects with US findings of suspected hyperplasia underwent 4-gland surgical procedures. All patients treated surgically continued to have normal serum calcium levels 6 to 18 months post-operatively.ConclusionPrimary hyperparathyroidism is caused most commonly by a solitary adenoma and less commonly by multigland hyperplasia of the parathyroid glands. Surgical resection is the only curative therapy. MIP has become a frequently used strategy, but there are limitations to current preoperative localization techniques. We conclude that US-guided FNA is a useful technique that facilitates MIP, with a high degree of specificity (95%) and sensitivity (91%). (Endocr Pract. 2007;13:333-337)     

Synchronous Parathyroid Carcinoma,Parathyroid Adenoma,and Papillary Thyroid Carcinoma in a Patient with Severe and Long-Standing Hyperparathyroidism

ObjectiveTo describe a patient presenting with the rare constellation of synchronous parathyroid carcinoma, parathyroid adenoma, and papillary thyroid carcinoma.MethodsWe summarize the clinical presentation, diagnostic work-up, surgical management, and pathologic features of our patient and review the pertinent literature.ResultsThe 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.ConclusionSynchronous 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. (Endocr Pract. 2009;15:463-468)     

Unusual Case of Calciphylaxis Associated with Primary Hyperparathyroidism Without Coexistent Renal Failure

ObjectiveTo report a case of calciphylaxis in a patient with primary hyperparathyroidism without coexistent renal failure.MethodsThe clinical, laboratory, and radiographic details of this case are reviewed, and the pathogenesis of calciphylaxis and the associated prognosis are discussed.ResultsA 52-year-old woman had progressive fatigue, cachexia, severe osteoporosis, and necrotizing skin lesions. Her serum calcium level was 16 mg/dL, serum phosphorus level was 2.13 mg/dL, and parathyroid hormone level was 2,257 pg/mL (reference range, 15 to 65). On physical examination, gangrenous skin lesions with black crusts were noted on her legs, abdomen, and gluteal region. A mass lesion was detected in the parathyroid region by both ultrasonography and a parathyroid scan. The patient underwent a bilateral neck exploration, and a parathyroid adenoma measuring 3.5 by 1.5 by 1.2 cm was found on pathologic examination. After the operation, biochemical findings normalized, and the skin lesions progressively improved.ConclusionSevere primary hyperparathyroidism may be a factor leading to calciphylaxis, even in the absence of renal failure and a high calcium-phosphate product. This potentially life-threatening condition should not be left untreated if the levels of serum calcium and parathyroid hormone are severely elevated. (Endocr Pract. 2008;14:368-372)     

Intérêt de l’imagerie hybride TEMP/TDM pour la détection de l’ectopie parathyroïdienne. Expérience du service de médecine nucléaire – CHU Mohammed VI,Marrakech

IntroductionHyperparathyroidism due to a parathyroid ectopia is a rare disease; it is the most common cause of persistent or recurrent hyperparathyroidism. Its treatment is exclusively surgical and the results of the surgery benefit from the contribution of preoperative imaging techniques. The aim of this work is to illustrate the interest of the single photon emission computed tomography/computed tomography (SPECT/CT) in the detection and treatment of ectopic parathyroid orientation.Case reportClinical case 1: a 41-year-old patient was followed for persistent primary hyperparathyroidism revealed by brown tumors at the level of the lower extremity of the right femur and tibia. The rate of parathormone was 1987.4 pg/mL. The cervical echography and the scanning were not decisive. The SPECT/CT, performed during a ^99mTc-MIBI scintigraphy and the same for the 2nd clinical case, has showed an area of high uptake projecting behind the left sternoclavicular joint. The diagnosis of ectopic parathyroid localization was retained. Resection and pathologic examination of the surgical specimen revealed parathyroid adenoma tissue. The evolution was marked by a normalization of the rate of parathormone. Clinical case 2: a 71-year-old patient who presents a clinico-biological board of primitive persistent hyperparathyroidism. A first scintigraphy (^99mTc-MIBI) realized in 2010 was negative. The rate of parathormone was 969 ng/L, the rate of calcium was 2.90 mmol/L. Two cervical ultrasound were normal. The SPECT/CT has objectified an area of high uptake in projection at the upper floor of the middle mediastinum. The diagnosis of ectopic parathyroid localization was retained. Surgical resection and histological study revealed a parathyroid adenoma tissue. The evolution was marked by a normalization of the rate of parathormone.DiscussionThe SPECT/CT has an important role in the management of patients with persistent or recurrent hyperparathyroidism. It can usually visualize ectopic parathyroid injury, specify its size and anatomic relationships to optimize surgical management.     

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 &lsqb;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.Abbreviations: BMD = bone mineral density GFR = glomerular filtration rate iPTH = intact parathyroid hormone MIBI = sestamibi PHPT = primary hyperparathyroidism PTH = parathyroid hormone SPECT = single-photon emission computed tomography Tc = technetium US = ultrasound     

Diagnostic d’une ectopie parathyroïdienne par scintigraphie double traceur

IntroductionA common cause of hyperparathyroidism is the presence of an ectopic parathyroid adenoma. Its diagnostic management remains a challenge and multiple imaging tests exist.Case reportA 39-year-old patient with hyperparathyroidism. At diagnosis, ultrasound and CT were not conclusive. MIBI scintigraphy has objectified a typical parathyroid ectopia in mediastinal position. Surgical resection confirmed parathyroid adenoma allowing standardization of laboratory patient.DiscussionMIBI scintigraphy is the most efficient technique for the diagnosis of hyperparathyroidism, especially in the case of an ectopic parathyroid.     

Three large, functioning cystic parathyroid adenomas

ObjectiveTo report a very rare case of 3 large, functioning cystic parathyroid adenomas causing primary hyperparathyroidism.MethodsWe present the history, clinical findings, laboratory test results, radiologic findings, endocrine workup results, intraoperative surgical challenges, and surgical pathology report of the study patient. We review the literature and discuss the importance of intraoperative parathyroid hormone (PTH) measurement in such cases.ResultsA 79-year-old woman presented with primary hyperparathyroidism and elevated levels of calcium and PTH. Localization studies confirmed the presence of a large right upper parathyroid adenoma. On exploration, a very large cystic parathyroid gland was identified at that location. Because intraoperative PTH levels remained elevated, further exploration was pursued, which revealed 2 more large cystic glands on the left side that were resected. This resulted in an adequate but slow PTH drop. The right lower gland appeared normal. On follow-up 4 days and 6 weeks after surgery, the calcium and PTH levels had normalized.ConclusionThis case highlights the aspects of intraoperative PTH use and underscores the need to exclude multigland disease even in the setting of a very large parathyroid cyst with concordant localization studies. (Endocr Pract. 2012;18:e14-e16)     

Beneficial Effect of Endocrinologist-Performed Ultrasonography on Preoperative Parathyroid Adenoma Localization

ObjectiveTo evaluate whether endocrinologist-performed ultrasonography improves the localization of parathyroid adenomas in patients with primary hyperparathyroidism.MethodsWe performed a retrospective analysis of consecutive patients with primary hyperparathyroidism due to a single adenoma who underwent surgery at the Dokuz Eylul University Hospital in Izmir, Turkey, between January 2000 and January 2008. Data regarding the localization of adenomas were obtained from surgical reports. Neck ultrasonography was performed in all patients as first-line imaging. Parathyroid ultrasonography was performed by a staff radiologist between January 2000 and December 2004. Beginning January 2005, parathyroid ultrasonography was performed blindly by an endocrinologist in addition to the staff radiologist. In the case of discordant preoperative localization between the endocrinologist- and radiologist-performed ultrasonography, surgery was performed according to the technetium Tc 99m sestamibi (MIBI) scan and endocrinologist-performed ultrasonography localization results.ResultsA total of 156 patients with primary hyperparathyroidism due to a single adenoma were included. Of the 156 patients, 139 also underwent MIBI scan. Ultrasonography localized 102 parathyroid adenomas (65%). The accuracy of the ultrasonography was improved in patients who underwent endocrinologist-performed ultrasonography. Endocrinologist-performed ultrasonography localized the adenoma correctly in 19 patients for whom the staff radiologist had reported a negative or unsuccessful localization. When ultrasonography results were combined with the MIBI scan findings, parathyroid adenomas were again more likely to be localized in patients who underwent operation after January 2005 and thus had endocrinologist-performed ultrasonography.ConclusionOur results suggest that endocrinologist-performed ultrasonography improves the preoperative localization of parathyroid adenoma. (Endocr Pract. 2009;15: 17-23)     

Unusual Recurrence of Hypercalcemia Due to Concurrent Parathyroid Adenoma and Parathyroid Sarcoidosis with Lymph Node Involvement

ObjectiveTo describe a patient presenting with the rare findings of synchronous parathyroid adenoma and parathyroid sarcoidosis.MethodsWe describe the clinical history, physical examination findings, laboratory values, imaging findings, and pathologic data of a man who developed recurrent se- vere hypercalcemia after successful parathyroidectomy.ResultsA 67-year-old man had the following initial blood test results: calcium, 11.1 mg/dL (reference range, 8.5-10.6 mg/dL); albumin 4.0 g/dL (reference range, 3.2-5.2 g/dL); intact parathyroid hormone, 166 pg/mL (refer- ence range, 10-69 pg/mL); creatinine, 1.9 mg/dL; 25-hy- droxyvitamin D, 15 ng/mL (reference range, 30-80 ng/ mL); and 1, 25-dihydroxyvitamin D, 44 pg/mL (reference range, 16-72 pg/mL). Chest x-ray was normal, and delayed images from a technetium Tc 99m sestamibi scan showed increased activity in the right lower pole of the thyroid. Two months after successful parathyroidectomy, the pa- tient was admitted to the hospital with a serum calcium concentration of 17 mg/dL. Pathologic examination of the resected gland confirmed the diagnosis of parathyroid ad- enoma, and subsequent review disclosed the presence of noncaseating granulomas within the adenoma.ConclusionsSarcoidosis with parathyroid involve- ment causing severe hypercalcemia is unique to this case.Recurrent hypercalcemia after successful resection of a parathyroid adenoma may require consideration of poten- tial causes other than the initial diagnosis. (Endocr Pract. 2010;16:463-467)     

Pre-Operative Localization of Parathyroid Adenoma: Performance of 4D Mri Parathyroid Protocol

Objective: Accurate pre-operative image localization is critical in the selection of minimally invasive parathyroidectomy as a surgical treatment approach in patients with primary hyperparathyroidism (PHPT). Sestamibi scan, ultrasound, computed tomography, and conventional magnetic resonance imaging (MRI) has varying accuracy in localizing parathyroid adenoma (PTA). Our group has previously shown that four-dimensional (4D) MRI is more accurate than conventional imaging in identifying single adenomas. In this study, we set out to determine if it is possible to accurately localize the quadrant of the adenoma using 4D MRI.Methods: We analyzed and matched the quadrants of PTA identified by pre-operative 4D-MRI with the operative findings during parathyroidectomy for PHPT at our institution during the study period. All resections were confirmed to be successful with an adequate decrease in intraoperative parathyroid hormone as defined by the Miami criterion.Results: A total of 26 patients with PHPT underwent pre-operative localization with the 4D MRI parathyroid protocol. Fourteen patients had true single-gland adenoma (SGA) and 12 patients had multi-gland disease (MGD). 4D MRI accurately identified all the SGA. Using this method, we were also able to localize the adenoma in the correct quadrant in 14 of the 18 patients with SGA. All 3 double adenomas were accurately identified using 4D MRI; however, MGD was only accurately identified 67% of the time. The 4D MRI had an overall 85% accuracy in distinguishing SGA from MGD.Conclusion: 4D MRI accurately identified single and double adenomas in their respective quadrants. However, accuracy was lower with MGD.Abbreviations: BNE = bilateral neck exploration; CT = computed tomography; IOPTH = intra-operative parathyroid hormone; MGD = multi-gland disease; MIBI = sestamibi; MIP = minimally invasive parathyroidectomy; MRI = magnetic resonance imaging; PHPT = primary hyperparathyroidism; PTA = parathyroid adenoma; PTH = parathyroid hormone; SGA = single-gland adenoma; SPECT = single photon emission computed tomography; 4D = four-dimensional     

Intraoperative Diagnostic Strategy to Distinguish Parathyroid Adenomas from Metastatic Thyroid Cancer

ObjectiveTo report the limitations of frozen section examination and the value of intraoperative tissue aspiration for parathyroid hormone assay to distinguish parathyroid adenomas from metastatic thyroid carcinoma.MethodsWe describe 2 patients with a biochemical diagnosis of primary hyperparathyroidism who underwent intraoperative frozen section analysis of suspected parathyroid tumors. Parathyroid gland aspiration for parathyroid hormone was also performed for confirmation.ResultsThe intraoperative frozen section examination of the suspected parathyroid tumors inaccurately identified the tumors as follicular carcinomas. The parathyroid gland aspirate, however, accurately substantiated the presence of parathyroid adenomas, rather than follicular cancers.ConclusionAspiration of a suspected parathyroid tumor for parathyroid hormone assay accurately determines whether a nodule is a parathyroid gland and facilitates intraoperative decision making, especially when frozen section diagnosis is misleading. (Endocr Pract. 2009; 15:454-457)     

Parathyroid carcinoma arising from four-gland hyperplasia

ObjectiveTo report the use of immunohistochemical staining for parafibromin, APC, and galectin-3 to evaluate the malignant potential of a resected parathyroid specimen in a patient initially presenting with primary hyperparathyroidism attributable to 4-gland hyperplasia, who subsequently developed metastatic parathyroid carcinoma.MethodsWe describe a patient with primary hyperparathyroidism who underwent a 3-gland resection of hypercellular parathyroid glands, with postoperative normalization of her serum calcium and parathyroid hormone levels. She returned 4 years later with recurrent hypercalcemia and underwent partial resection of her remaining hypercellular parathyroid gland, without improvement of her hypercalcemia. Selective venous sampling localized the source as draining into her azygos vein, and metastatic parathyroid carcinoma was ultimately diagnosed.ResultsImmunohistochemical staining for parafibromin, APC, and galectin-3 suggested the malignant potential of the atypical adenoma removed during the patient’s original operation, which is believed to be the source of her metastatic disease. Access to this information by the treating surgeon may have prompted a more extensive en bloc resection or more vigilant follow-up that could have altered the patient’s clinical course.ConclusionImmunohistochemical staining for parafibromin, APC, and galectin-3 can be used to help distinguish the source of metastatic disease in patients with parathyroid carcinoma. Selective venous sampling may help localize metastatic parathyroid carcinoma when the source is otherwise not apparent. (Endocr Pract. 2011;17:e37-e42)     

The Detection of Preoperative Parathyroid Lesions: The Success of Ultrasonography,Technetium-99m Methoxyisobutylisonitrile Parathyroid Scintigraphy,and Single-Photon Emission Computed Tomography–Computed Tomography

ObjectiveWe aimed to find and compare the efficacy of ultrasonography (US), technetium-99m methoxyisobutylisonitrile parathyroid scintigraphy (MIBI-S), and single-photon emission computed tomography–computed tomography (SPECT-CT) in detecting the localization of parathyroid adenomas in patients with primary hyperparathyroidism.MethodsIn total, 348 patients were included in this study. Preoperative parathyroid imaging with US, MIBI-S, and SPECT-CT was evaluated and compared with operative findings. The results of the imaging methods were compared with pathology and operation reports.ResultsIn 318 patients (91.3%), one of the imaging methods was able to localize the lesion correctly. US detected the localization of the parathyroid lesions correctly in 268 patients (77%), whereas SPECT-CT and MIBI-S were correct in 254 (73%) and 209 (60%) patients, respectively. There was a statistically significant relationship between the parathyroid hormone (PTH) level and 3 imaging methods’ success rates (P < .05). The PTH cut-off value, which best determined the correct localization, was 152.5 pg/mL for US, 143 pg/mL for MIBI-S, and 143 pg/mL for SPECT-CT. It was observed that the correct localization rate for parathyroid lesions increased with higher PTH levels.ConclusionIn our study population, US was more successful, in most cases, than other imaging methods in localizing parathyroid lesions but SPECT-CT was more accurate in localizing mediastinal lesions. In addition, it was found that preoperative PTH levels affect the accuracy of imaging methods.     

Unusual Manifestation of Parathyroid Carcinoma in the Setting of Papillary Thyroid Cancer

ObjectiveTo describe a rare manifestation of parathyroid carcinoma in association with papillary thyroid carcinoma.MethodsWe describe the clinical history, findings on physical examination, results of laboratory studies, imaging findings, and histopathologic features of a woman with 2 previously palpable thyroid nodules and mild hypercalcemia.ResultsA 79-year-old woman presented to our endocrinology clinic for reevaluation of 2 thyroid nodules and long-standing hyperparathyroidism. She initially had undergone assessment 6 years previously, at which time an intact parathyroid hormone level was 89 pg/mL (reference range, 10 to 69) and the serum calcium concentration was 10.4 mg/dL (reference range, 8.2 to 10.2) in conjunction with normal alkaline phosphatase, creatinine, and 25-hydroxyvitamin D levels. Subsequently, she was found to have multifocal papillary thyroid cancer in the right thyroid lobe and a 5-cm parathyroid carcinoma in the left side.ConclusionSynchronous parathyroid and thyroid carcinomas are extremely rare. To our knowledge, our current case is the first documented patient with parathyroid carcinoma who had a clinical presentation consistent with longstanding mild adenoma in addition to synchronous papillary thyroid carcinoma. (Endocr Pract. 2010;16:664-668)     

Thyroid-Related Factors that Influence Preoperative Localization of Parathyroid Adenomas

ObjectiveTo evaluate the effect that thyroid-related factors have on the preoperative localization of parathyroid adenomas.MethodsThis retrospective study included adult patients who were referred for further evaluation of primary hyperparathyroidism between December 2005 and October 2009 at a teaching and research hospital in Turkey. High-frequency ultrasonography and sestamibi scintigraphy (MIBI) were performed in all patients. Surgical procedure involved focal or bilateral exploration on the basis of concordant or discordant imaging studies. Selection of patients for minimally invasive parathyroidectomy was made based on the presence or absence of a single parathyroid adenoma detected by both ultrasonography and MIBI scan. Patients with negative or discordant imaging studies and a concomitant thyroid nodule underwent bilateral neck exploration.ResultsTwo hundred and forty-eight patients with primary hyperparathyroidism who underwent parathyroidectomy were included in the study. Parathyroid gland abnormalities were successfully detected preoperatively by ultrasonography in 231 patients and by MIBI scan in 152 patients. When used together, ultrasonography and MIBI scan were unsuccessful in detecting an abnormality in 11 cases. MIBI scan visualized a lesion in 6 cases that remained undiagnosed by ultrasonography. Fifty-six of 85 patients with lesions detected by ultrasonography, but not by MIBI scan, had thyroid nodules. The frequency of thyroid nodules was higher in the 96 patients in whom a MIBI scan could visualize a parathyroid lesion than in the 152 patients in whom MIBI scan was successful (P = .004). No difference was observed regarding ipsilateral thyroid lobe involvement or nodule volume. Parathyroid adenomas were significantly smaller in patients with negative MIBI scans (P < .001).ConclusionOur results suggest that ultrasonography is more sensitive than MIBI scan in the detection of parathyroid adenomas, particularly in the presence of small parathyroid adenomas or other thyroid related-factors. (Endocr Pract. 2012;18:26-33)     

Mediastinal parathyroidectomy with the da Vinci robot

Mediastinal parathyroid glands are often located in a position which is inaccessible through a cervical approach. Because of the significant morbidity of open surgery, the need for minimal invasive approaches is high. More recently, robotic systems have been introduced to refine the dissection and optimize the view in the mediastinal region. We present two cases. The first case is a 34-year-old woman who was diagnosed with primary hyperparathyroidism. Because a bilateral neck dissection disclosed no parathyroid adenoma, we performed a parathyroid sestamibi scan and computed tomographic scan of neck and mediastinum to look for aberrant parathyroid glands. Both showed a parathyroid adenoma in the mediastinum on the left side. The second case is a 66-year-old man. A sestamibi scan showed a parathyroid adenoma of 3 cm in the superior mediastinum which was confirmed by and computed tomographic scan. In both cases, we performed a parathyroidectomy with the da Vinci robotic system through a left-sided approach. Three thoracoports were inserted around the mammary gland for the robot and a fourth auxiliary port was positioned in between. Single-lung ventilation was installed, and the mediastinum was entered by opening the parietal pleura along the left phrenic nerve. The upper margin for dissection was the left brachiocephalic vein that was followed until the right pleura. All the tissue in front of the pericardium was dissected en bloc. The sinking test of the nodule and a preoperative frozen section analysis confirmed the diagnosis of parathyroid adenoma, which was also proven by rapid parathyroid hormone analysis. The resection of a parathyroid adenoma from the aortopulmonary window represents an ideal case for robotic surgery.     

Suppressibility of Parathyroid Hormone in Primary Hyperparathyroidism

ObjectiveTo describe an unusual case of pathologically confirmed primary hyperparathyroidism in a patient presenting with severe hypercalcemia and an undetectable parathyroid hormone (PTH) level.MethodsWe present a detailed case report and outline the serial laboratory findings. In addition, the possible causes of low serum PTH levels in the setting of primary hyperparathyroidism are discussed.ResultsA 16-year-old female patient presented with severe epigastric pain, found to be attributable to acute pancreatitis. At hospital admission, her serum calcium concentration was high (14.0 mg/dL); the patient also had a normal serum phosphorus level of 3.6 mg/dL and an undetectable PTH level (< 0.2 pmol/L). An evaluation for non-PTH-mediated causes of hypercalcemia revealed a partially suppressed thyroid-stimulating hormone concentration and a below normal 1,25-dihydroxyvitamin D level, consistent with her suppressed PTH. One week after the patient was dismissed from the hospital, repeated laboratory studies showed a serum calcium value of 11.1 mg/dL, a serum phosphorus level of 2.8 mg/dL, and an elevated PTH concentration of 11.0 pmol/L, consistent with primary hyperparathyroidism. A repeated 1,25-dihy-droxyvitamin D measurement was elevated. A parathyroid scan showed a parathyroid adenoma in the left lower neck area, and she subsequently underwent successful surgical resection of a pathologically confirmed parathyroid adenoma.ConclusionThis case demonstrates that the serum PTH level can be suppressed in patients with primary hyperparathyroidism. Moreover, it emphasizes the need for careful evaluation of the clinical context in which the PTH measurement is determined. Consideration should be given to repeating measurement of PTH and serum calcium levels when the initial laboratory evaluation of hypercalcemia is unclear because dynamic changes in calcium metabolism may occur in the presence of secondary contributing factors. (Endocr Pract. 2007;13:785-789)     

Significance of Elevated Parathyroid Hormone After Parathyroidectomy

ObjectiveTo review the prevalence of parathyroid hormone elevation after parathyroidectomy for primary hyperparathyroidism and to discuss possible mechanisms.MethodsA Medline search of the English-language literature published between 1990 and 2009 was performed using the search terms “elevated PTH after parathyroidectomy.” All of the identified articles reported either prospective or retrospective studies without control groups. Studies that included patients with secondary or tertiary hyperparathyroidism were not reviewed.ResultsWithin 1 week to 5 years after parathyroidectomy, 9% to 62% of patients with a normal serum calcium concentration are reported to have an elevated parathyroid hormone concentration. No evidence suggests that postoperative normocalcemic parathyroid hormone elevation is an indication of surgical failure and recurrent hypercalcemia. Preoperative findings in patients with postoperative parathyroid hormone elevation include lower vitamin D concentration, higher concentrations of bone turnover markers, and higher parathyroid hormone concentration. Potential mechanisms for parathyroid hormone elevation in the setting of normocalcemia include vitamin D deficiency, hungry bone syndrome, and parathyroid hormone resistance. Study findings suggest a possible benefit of postoperative calcium and vitamin D supplementation, but no randomized trials have been done.ConclusionElevation of parathyroid hormone commonly occurs after parathyroidectomy for primary hyperparathyroidism, although the underlying mechanism remains unclear. (Endocr Pract. 2010;16:112-117)     

Serum Monocyte Chemokine Protein-1 Levels Before and After Parathyroidectomy in Patients with Primary Hyperparathyroidism

ObjectiveTo investigate the effects of parathyroidectomy on serum monocyte chemokine protein-1 (MCP- 1) levels in patients with primary hyperparathyroidism (PHPT).MethodsForty-three PHPT patients, age 56 ± 12 years, underwent minimally invasive parathyroidectomy. Serum samples were collected at 0 and 15 to 20 minutes after parathyroid adenoma removal. Serum samples were stored at -70°C until time of assay.ResultsIn 40 PHPT patients with a single adenoma, MCP-1 levels decreased from 342 ± 103 to 250 ± 77 pg/ mL (P < .001) 15 to 20 minutes after parathyroid adenoma removal. MCP-1 levels were positively correlated with intact parathyroid hormone (PTH) levels (R = 0.47; P < .01). In 3 PHPT patients with double parathyroid adenoma, MCP-1 levels did not decrease after removal of the first adenoma but decreased 15 to 20 minutes after second adenoma removal.ConclusionOur results provide evidence that the decrease in serum intact PTH due to minimally invasive parathyroidectomy results in an immediate decrease in serum MCP-1 levels. (Endocr Pract. 2014;20:1165-1169)