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Introduction Surgical treatment of hyperparathyroidism related to chronic kidney disease is a real challenge for Brazilian public health care. High cost medications and long waiting lines to perform preoperative exams, especially technetium Tc 99m Sestamibi (MIBI) are some of the reasons. Despite the reality that the aid of localization exams are questionable in this scenario, doctors are too apprehensive in performing surgery without it. Objective The study aimed at evaluating the efficacy of surgery for renal hyperparathyroidism without preoperative MIBI. Methods A total of 114 patients were surgically treated. Total parathyroidectomy with autotransplantation and subtotal parathyroidectomy were carried out without preoperative MIBI. Results and conclusion Among the 114 patients undergoing surgery, 37 had secondary hyperparathyroidism in dialysis replacement, and 77 patients had post-renal transplant persistent disease. We were successful in 107 cases with only 7 failures (93.8% of success rate). Among these failures, only one parathyroid gland was not found in 4 cases, 2 parathyroid glands were not found in 2 cases and in 1 patient the 4 glands were found but this patient remained hypercalcemic and a postoperative diagnosis of supernumerary parathyroid gland was made. Surgery for treatment of renal hyperparathyroidism proved to be an effective (93.8%) and reproductible procedure, even without MIBI.

Neck ultrasound (US) and Technetium-99 m Sestamibi (MIBI) scan are the most commonly used imaging studies for preoperative localization of parathyroid adenomas. The aim of this study was to determine the added value of MIBI scan and its effect on the operative plan via a hypothetical model where a stepwise approach is conducted and MIBI is considered only after the ultrasound is evaluated. Patients who underwent parathyroidectomy for primary hyperparathyroidism (PHPT) between 2012 and 2019 at two tertiary centers were included. Data collected included demographic data, preoperative workup, operative findings and follow-up. The added value of MIBI scans was determined for patients with positive ultrasound. A total of 513 patients with positive US result and a MIBI scan were included. If a stepwise approach was conducted then MIBI scan would not change the operative plan in 492 (95.9%). Among the remaining 21 patients, MIBI scan would correctly change the ultrasound-based operative plan in only 12 (2.3%) patients, while incorrectly change the plan in 9 (1.8%), resulting in unnecessary exploration of the contralateral side. In patients with sonographic appearance of a parathyroid gland larger than 1.2 cm, MIBI scan would correctly change the operative plan in only 1 of the 287 (0.35%) patients. Our study suggests that the routine use of MIBI scans may have limited added value in patients with PHPT and a positive neck ultrasound, especially in those with adenoma size larger than 1.2 cm. Positive ultrasound alone may be sufficient for the preoperative localization of parathyroid disease.

Summary Brown tumors are osteoclastic, benign lesions characterized by fibrotic stroma, intense vascularization and multinucleated giant cells. They are the terminal expression of the bone remodelling process occurring in advanced hyperparathyroidism. Nowadays, due to earlier diagnosis, primary hyperparathyroidism keeps few of the classical manifestations and brown tumors are definitely unexpected. Thus, it may happen that they are misdiagnosed as primary or metastatic bone cancer. Besides bone imaging, endocrine evaluation including measurement of serum parathyroid hormone and calcium (Ca) levels supports the pathologist to address the diagnosis. Herein, a case of multiple large brown tumors misdiagnosed as a non-treatable osteosarcoma is described, with special regards to diagnostic work-up. After selective parathyroidectomy, treatment with denosumab was initiated and a regular follow-up was established. The central role of multidisciplinary approach involving pathologist, endocrinologist and oncologist in the diagnostic and therapeutic work-up is reported. In our opinion, the discussion of this case would be functional especially for clinicians and pathologists not used to the differential diagnosis in uncommon bone disorders. Learning points: Brown tumors develop during the remodelling process of bone in advanced and long-lasting primary or secondary hyperparathyroidism. Although rare, they should be considered during the challenging diagnostic work-up of giant cell lesions. Coexistence of high parathyroid hormone levels and hypercalcemia in primary hyperparathyroidism is crucial for the diagnosis. A detailed imaging study includes bone X-ray, bone scintiscan and total body CT; to rule out bone malignancy, evaluation of bone lesion biopsy should include immunostaining for neoplastic markers as H3G34W and Ki67 index. If primary hyperparathyroidism is confirmed, selective parathyroidectomy is the first-line treatment. In advanced bone disease, treatment with denosumab should be considered, ensuring a strict control of Ca levels.

Summary Brown tumors (BTs) are expansile osteolytic lesions complicating severe primary hyperparathyroidism (PHPT). Clinical, radiological and histological features of BTs share many similarities with other giant cell-containing lesions of the bone, which can make their diagnosis challenging. We report the case of a 32-year-old man in whom an aggressive osteolytic lesion of the iliac crest was initially diagnosed as a giant cell tumor by biopsy. The patient was scheduled for surgical curettage, with a course of neoadjuvant denosumab. Routine biochemical workup prior to denosumab administration incidentally revealed high serum calcium levels. The patient was diagnosed with PHPT and a parathyroid adenoma was identified. In light of these findings, histological slices of the iliac lesion were reviewed and diagnosis of a BT was confirmed. Follow-up CT-scans performed 2 and 7 months after parathyroidectomy showed regression and re-ossification of the bone lesion. The aim of this case report is to underline the importance of distinguishing BTs from other giant cell-containing lesions of the bone and to highlight the relevance of measuring serum calcium as part of the initial evaluation of osteolytic bone lesions. This can have a major impact on patients’ management and can prevent unnecessary invasive surgical interventions. Learning points: Although rare, brown tumors should always be considered in the differential diagnosis of osteolytic giant cell-containing bone lesions. Among giant cell-containing lesions of the bone, the main differential diagnoses of brown tumors are giant cell tumors and aneurysmal bone cysts. Clinical, radiological and histological characteristics can be non-discriminating between brown tumors and giant cell tumors. One of the best ways to distinguish these two diagnoses appears to be through biochemical workup. Differentiating brown tumors from giant cell tumors and aneurysmal bone cysts is crucial in order to ensure better patient care and prevent unnecessary morbid surgical interventions.

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.

Primary hyperparathyroidism (PHPT) is the most common cause of hypercalcemia; patients are usually asymptomatic and the cause in 80-85% of cases is a single parathyroid adenoma (PA). Parathyroid adenomas arise from clonal expansion of tumor cells and may be located either posteriorly to the thyroid lobes or in ectopic sites. The incidence of intrathyroidal PAs varies from 1% to 6% and although uncommon, they pose certain diagnostic difficulties which may complicate treatment. The identification of the adenoma requires a combination of clinical evidence, imaging information and cytological findings due to the challenging distinction between thyroid and parathyroid lesions. We present the case of a patient with a large, partially cystic intrathyroidal parathyroid adenoma which was initially identified as a malignant thyroid nodule. We discuss the caveats that present in these rare cases and the important clinical and histological features that aid in the final diagnosis. In the case of our patient the cytological similarities between thyroid malignant cells and parathyroid cells, in combination with the negative sestamibi scan, resulted in a more invasive surgery than that a single parathyroid adenoma would require. Clinicians need to be vigilant in terms of the similarities between parathyroid and thyroid cytology in order to provide optimal patient care in these rare cases.

Highlights • Neonatal severe primary hyperparathyroidism is an exceedingly rare condition that has high mortality and morbidity if left untreated. • Medical therapy must be initiated as soon as the condition is diagnosed, and early surgery must be performed in patients who are refractory to the medical therapy. • Scintigraphic studies might sometimes fail to detect ectopic parathyroid glands. Intraoperative parathormone monitoring is particularly important to ensure complete removal of the parathyroid glands., Introduction Neonatal severe primary hyperthyroidism is an extremely rare disorder that occurs in the first six months of life. Early recognition and prompt surgical intervention are of vital importance for survival and to avoid neurological sequel. Hypotonia, lethargy, respiratory distress, and growth and developmental delay occur in association with elevated serum parathormone levels and hypercalcemia (Gannon et al., 2014). Definitive therapy involves total parathyroidectomy. Case presentation We are presenting a patient with Neonatal severe primary hyperparathyroidism, who successfully underwent total parathyroidectomy. The patient had been followed up with medical therapy until he was seven months old, with no adequate clinical response to medical therapy. Parathormone levels rapidly declined following total parathyroidectomy, and the parathormone level fell to zero after removal of the ectopic tissue with a second surgery, and the patient was discharged with full recovery. Discussion Sestamibi scintigraphy might not always show an ectopic parathyroid gland. In such conditions, confirmation of parathyroid glands excised with total parathyroidectomy by frozen biopsy is not sufficient to terminate surgery. Intraoperative parathormone monitoring is particularly important at this point. Persistently elevated parathormone levels should suggest a remnant parathyroid tissue at the surgical site or an ectopic parathyroid gland that needs to be excised. Conclusion Neonatal severe primary hyperparathyroidism is a life-threatening condition. Early surgery is life-saving in cases in whom medical therapy fails to control the disease.

Background Intra-operative identification of parathyroid glands is often a challenge for surgeons performing parathyroid or thyroid surgery. Parathyroid glands stimulated by near-infrared light emit autofluorescence, which allows their discrimination from all other tissues in the region, and this may be of value during thyroid and parathyroid surgery. In this study, we present the results of the utilization of a low-cost device developed for the identification of parathyroid glands in surgery for primary hyperparathyroidism. Case presentation In 5 patients operated in our hospital with the diagnosis of primary hyperparathyroidism and non-concordant ultrasonography and Sestamibi scan, we used a 780 nm Light Emitting Diode (LED) to stimulate the cervical area. The resulting autofluorescence was visualized with night vision goggles with a 832 nm filter assembled. In all the five patients, an easily distinguishable nodule was identified and excised, and confirmed as parathyroid adenoma by histological exam. Intra-operative PTH assay showed significant decrease compared with basal values, fulfilling the Miami Criteria for surgical success in use in our institution. Conclusion The utilization of autofluorescence for intra-operative identification of parathyroid glands may have a clinical application in surgery for primary hyperparathyroidism, being of special utility when ultrasonography and Sestamibi Scan are non concordant.

The most common cause of primary hyperparathyroidism (PHPT) is a solid parathyroid adenoma. Less than 2% of cases of PHPT are caused by cystic parathyroid adenomas formed from degeneration of pre-existing solid parathyroid adenomas. Cystic parathyroid adenomas are non-functional in over 90% of cases. In this case we describe management of a 56-year-old man with acute-onset polydipsia, polyuria, xerostomia, nausea, and constipation. Serum chemistry upon admission revealed hypercalcemia, hyperparathyroidism, and reduced serum phosphorus. Neck sonogram revealed a predominantly anechoic lesion later confirmed by pathology to be a cystic parathyroid adenoma in the right thyroid lobe. Sestamibi scan did not show uptake in parathyroid gland, and parathyroid hormone (PTH) was elevated in fine-needle aspiration sample. Otolaryngology removed the cystic lesion via surgical excision, which led to normalization of PTH level. This case demonstrates the importance of evaluation of cystic components for PTH levels and if confirmed should be treated as a parathyroid adenoma.

Introduction: Primary hyperparathyroidism (PHPT) is a rare condition in the pediatric population. Parathyroid carcinoma (PC) is a very uncommon cause of PHPT, accounting for < 1% of pediatric PHPT cases. It is challenging to distinguish between parathyroid adenoma (PA), the most common cause of PHPT, and PC. In this report, we described a young female who presented with a history of progressive limping and was finally diagnosed with PC. Case Presentation: A 15-year-old girl presented with progressive limping and bone pain for 8 years. She was referred by an orthopedic surgeon because of elevated intact parathyroid hormone (iPTH) for further evaluation. Physical examination revealed a large, firm, and non-tender neck mass, left hip tenderness, and limited range of motion. The initial biochemistry tests showed a borderline high calcium level of 10.8 mg/dl, an elevated iPTH level of 2876 pg/mL, and a decreased phosphorus level of 2.4 mg/dL. The 99mTechnetium (Tc) sestamibi scan displayed early intense activity in the right thyroid lobe persisting in the three-hour repeat scan, compatible with a parathyroid lesion. The patient underwent right-sided neck exploration and parathyroidectomy. Intraoperative and pathology findings confirmed the diagnosis of PC. Immunohistochemistry (IHC) staining revealed creatine kinase (CK) and CD31 in endothelial cells of the tumor. Ki67 staining was also positive in 2% - 3% of tumor cells. The whole exome sequencing (WES) study was negative for cell division cycle 73 (CDC73) and multiple endocrine neoplasia 1 (MEN1) genes. Conclusions: PC should be considered as a differential diagnosis of PHPT in the pediatric population, even in the presence of mild hypercalcemia.

Multiple endocrine neoplasia 1 (MEN1) is a rare genetic syndrome characterized by the manifestation of tumors in endocrine glands most often in the parathyroid gland (PG). Treatment may involve several parathyroidectomies (PTX), especially in young patients, which increases the risk of postoperative complications. We present a 16-year-old patient with a family history of MEN1 syndrome. The patient started to show biochemical signs of hyperparathyroidism (HPT) and hypercalcemia at the age of 10. One and a half years later a PTX was successfully performed with removal of the two left PGs. However, a rise in plasma parathyroid hormone and ionized calcium was observed 4 years later. Preoperative noninvasive imaging with 99mTc-sestamibi scintigraphy showed no definitive parathyroid adenoma. A 11C-methionine position emission tomography combined with MRI (MET-PET/MRI) was then performed and detected a focus posterior to the lower part of the right thyroid lobe. Intraoperative angiography with fluorescence and indocyanine green dye was used to assess the vascularization of the remaining PGs. The lower right PG was removed. The patient was discharged with normalized biochemical values and without postoperative complications. Recurrence of primary HPT is frequent in MEN1 patients which often necessitates repeated operations. Our case report showed that the use of advanced noninvasive preoperative imaging techniques and intraoperative fluorescent imaging are valuable tools and should be taken into consideration in selected cases to avoid postoperative complications. To our knowledge, this is the first case where MET-PET/MRI has been used to detect parathyroid pathology. Learning points: MEN1 patients will develop parathyroid disease, which eventually will lead to surgical treatment with removal of the pathological glands. Preoperatively usage of MRI combined with PET tracers such as 11C-methionine and 18F-Fluorocholine are able to detect parathyroid pathology with a higher sensitivity than conventional imaging. Techniques using intraoperatively angiography with fluorescence and florescent dyes allow surgeons to verify the vascularization of each parathyroid gland. Optimization of noninvasive preoperative imaging techniques and intraoperative fluorescent imaging are valuable tools and should be taken into consideration when performing PTX consecutively in the same patient to avoid postoperative complications.

Summary Isolated, adult-onset central hypothyroidism is very rare, and its diagnosis can be challenging. A 42-year-old patient was referred for evaluation of a 2.8 cm thyroid nodule. She referred symptoms that could be attributed to hypothyroidism and thyroid tests showed low TSH and normal-low levels of free T4. However, evaluation of the remaining pituitary hormones and pituitary MRI were normal, yet a radionuclide scanning revealed that the thyroid nodule was ‘hot’ and the tracer uptake in the remaining thyroid tissue was suppressed. Interpretation of these studies led to a misdiagnosis of subclinical hyperthyroidism and the patient was treated with radioiodine. Soon after treatment, she developed a frank hypothyroidism without appropriate elevation of TSH and the diagnosis of central hypothyroidism was made a posteriori. Long term follow-up revealed a progressive pituitary failure, with subsequent deficiency of ACTH and GH. This case should alert to the possibility of overlooking central hypothyroidism in patients simultaneously bearing primary thyroid diseases able to cause subclinical hyperthyroidism. Learning points: Although rarely, acquired central hypothyroidism can occur in the absence of other pituitary hormone deficiencies. In these cases, diagnosis is challenging, as symptoms are unspecific and usually mild, and laboratory findings are variable, including low, normal or even slightly elevated TSH levels, along with low or low-normal concentrations of free T4. In cases with low TSH levels, the coexistence of otherwise common disorders able to cause primary thyroid hyperfunction, such as autonomous nodular disease, may lead to a misdiagnosis of subclinical hyperthyroidism.

Summary Distinguishing primary hyperparathyroidism (PHPT) from familial hypocalciuric hypercalcaemia (FHH) can be challenging. Currently, 24-h urinary calcium is used to differentiate between the two conditions in vitamin D replete patients, with urinary calcium creatinine clearance ratio (UCCR) 0.02 supportive of PHPT. A 26-year-old Caucasian gentleman presented with recurrent mild hypercalcaemia and inappropriately normal parathyroid hormone (PTH) following previous parathyroidectomy 3 years prior. He had symptoms of fatigue and light-headedness. He did not have any other symptoms of hypercalcaemia. His previous evaluation appeared to be consistent with PHPT as evidenced by hypercalcaemia with inappropriately normal PTH and UCCR of 0.0118 (borderline low using guidelines of >0.01 consistent with PHPT). He underwent parathyroidectomy and three parathyroid glands were removed. His calcium briefly normalised after surgery, but rose again to pre-surgery levels within 3 months. Subsequently, he presented to our centre and repeated investigations showed 24-h urinary calcium of 4.6 mmol/day and UCCR of 0.0081 which prompted assessment for FHH. His calcium-sensing receptor (CASR) gene was sequenced and a rare inactivating variant was detected. This variant was described once previously in the literature. His mother was also confirmed to have mild hypercalcaemia with hypocalciuria and, on further enquiry, had the same CASR variant. The CASR variant was classified as likely pathogenic and is consistent with the diagnosis of FHH. This case highlights the challenges in differentiating FHH from PHPT. Accurate diagnosis is vital to prevent unnecessary surgical intervention in the FHH population and is not always straightforward. Learning points: Distinguishing FHH from PHPT with co-existing vitamin D deficiency is difficult as this can mimic FHH. Therefore, ensure patients are vitamin D replete prior to performing 24-h urinary calcium collection. Individuals with borderline UCCR could have either FHH or PHPT. Consider performing CASR gene sequencing for UCCR between 0.01 and 0.02. Parathyroid imaging is not required for making the diagnosis of PHPT. It is performed when surgery is considered after confirming the diagnosis of PHPT.

Currently, neck ultrasound is the preferred preoperative imaging in patients with secondary/tertiary hyperparathyroidism, and the use of Tc-99m sestamibi scan is limited in these patients. We conducted this study to compare the diagnostic utilities of F-18 fluorocholine PET/CT, Tc-99m sestamibi scintigraphy, and neck ultrasound for localizing hyperfunctioning parathyroid glands in secondary/tertiary hyperparathyroidism. We prospectively enrolled 30 dialysis patients with a diagnosis of secondary/tertiary hyperparathyroidism; of these, 27 participants underwent all three imaging modalities, including dual-phase F-18 fluorocholine PET/CT (PET acquired 5 and 60 min after tracer injection), dual-phase Tc-99 m sestamibi SPECT/CT, and neck ultrasound. All patients underwent parathyroidectomy after imaging. We compared the lesion-based sensitivity, specificity, and accuracy of the three image tools using histopathology as the reference. A total of 27 patients (107 lesions) underwent all three imaging modalities and entered the final analysis. The lesion-based sensitivities of F-18 fluorocholine PET/CT, Tc-99m sestamibi, and ultrasound were 86%, 55%, and 62%, respectively (both p

The aim of this study is to evaluate the effectiveness of preoperative imaging localization of hyper functioning parathyroid glands and comparing it with operative neck exploration in secondary hyperparathyroidism. This study was performed in Minia University Hospital between January 2017 and May 2018. Twenty patients with secondary hyperparathyroidism were included in this study. Ultrasonography was done for all patients, and then we classify our patients into two groups: in group 1 patients, Technetium-99 m sestamibi scan and computed tomography were done preoperatively while in group 2, patients underwent operation with neck exploration directly without other preoperative localization procedures. Mean age in our cases was 45.2 ± 9.46, while the most affected age group was (40–49) years by (35%), then (30–39) years by (30%), then (50–59) years by (25%), and then (≥ 60) years by (10%), while females were more affected than male by (75%) of cases. CT sensitivity in detection of parathyroid disease was 70%, and sestamibi detects 80% while neck exploration detection sensitivity was 100%. Neck exploration is the only reliable localization procedure in the cases of secondary hyperparathyroidism.

Brown tumor is a bone lesion that arises in the setting of excess osteoclast activity in hyperparathyroidism. It consists of fibrous tissue, woven bone, and supporting vasculature, while contains no matrix. The characteristic of brown-colored lesion is a result of hemosiderin deposition into the osteolytic cysts. Two cases of young women aged 26 and 29 years old, respectively, are known with a history of end-stage renal disease (ESRD). Dialysis is performed two times/week over the last 7 years. Our patients presented with an intraoral mass of the hard palate since 12 months ago and decreased body height of 10 cm. The lesion causes difficulties in swallowing and talking. Laboratory workup showed elevated parathormone or PTH (3.391 pg/mL and >5.000 pg/mL). Neck ultrasound showed enlargement of the parathyroid glands. Supporting examination to diagnose brown tumor are neck ultrasound, CT of the neck, and parathyroid sestamibi scan. We performed parathyroidectomy. Pathology revealed hyperplasia of the parathyroid. The tumor regressed significantly within 2 weeks following the surgery, and we still observe tumor regression as well as reduction in PTH level. As clinicians, we should be alert to other possible causes of bony lesions. Clinical examination, laboratory finding, and imaging present important information to diagnose brown tumor.

Background Single parathyroid adenoma is the commonest cause of primary hyperparathyroidism. Localization of the affected gland preoperatively is a critical step in management. Surgery is considered as the main line of treatment for single parathyroid adenoma. Focused technique for parathyroid excision was found by many researchers to have a good success rate even without intraoperative parathyroid hormone measurement. Objective The aim of this study was to assess the feasibility, safety, and adequacy of focused parathyroidectomy via an open lateral approach using preoperative positive Sestamibi (MIBI) scan and/or ultrasound without utilizing any intraoperative aiding tools. Methods A case-series prospective analysis of focused open parathyroidectomy for 20 patients presented to the department of surgery or referred from the orthopedic department between October 2012 and January 2015 at the Faculty of Medicine, Al-Azhar University, Cairo, Egypt, diagnosed as sporadic hyperparathyroidism with either positive MIBI scan or ultrasound were done. Normalization of the postoperative levels of serum calcium and PTH was considered as a marker of success. Data entry and analysis were done using the IBM-SPSS version 22. Results In this study, focused minimal access parathyroidectomy was successful in 95% with no major surgical complications, i.e., recurrent laryngeal nerve palsy or permanent hypoparathyroidism. The patient's mean age was 46.5±12 years. The preoperative serum calcium level ranged from 8.8 to 15.2 mg/dL. The parathyroid hormone level was elevated ranging from 123-2000 pg/mL. In 90% of the cases, serum levels of alkaline phosphatase were elevated, while serum phosphorus was low with range 1.5-4.7 mg/dL. The left inferior parathyroid gland was the most commonly involved gland (40%). Using ultrasound and Sestamibi scan for preoperative localization was accurate in 75% and 90%, respectively. When both techniques were combined localization accuracy increased to 95%. Conclusion Our study has shown that focused parathyroidectomy is considered as a good option for single gland disease even if there are no available intraoperative helping aids, provided that good patient selection is undertaken.

Introduction Highly specific preoperative localizing test is required to select patients for minimally invasive parathyroidectomy (MIP) in lieu of traditional four-gland exploration. We hypothesized that Tc-99m sestamibi scan interpretation incorporating numerical measurements on the degree of asymmetrical activity from bilateral thyroid beds can be useful in localizing single adenoma for MIP. Methods We devised a quantitative interpretation method for Tc-99m sestamibi scan based on the numerically graded asymmetrical activity on early phase. The numerical ratio value of each scan was obtained by dividing the number of counts from symmetrically drawn regions of interest (ROI) over bilateral thyroid beds. The final pathology and clinical outcome of 109 patients were used to perform receiver operating curve (ROC) analysis. Results Receiver operating curve analysis revealed the area under the curve (AUC) was calculated to be 0.71 (P = 0.0032), validating this method as a diagnostic tool. The optimal cut-off point for the ratio value with maximal combined sensitivity and specificity was found with corresponding sensitivity of 67.9% (56.5-77.2%, 95% CI) and specificity of 75.0% (52.8-91.8%, 95% CI). An additional higher cut-off with higher specificity with minimal possible sacrifice on sensitivity was also selected, yielding sensitivity of 28.6% (18.8-38.6%, 95% CI) and specificity of 90.0% (69.6-98.8%, 95% CI). Conclusions Our results demonstrated that the more asymmetrical activity on the initial phase, the more successful it is to localize a single parathyroid adenoma on sestamibi scans. Using early-phase Tc-99m sestamibi scan only, we were able to select patients for minimally invasive parathyroidectomy with 90% specificity.

Background The objective of this study was to evaluate the performance of dual-energy computed tomography (DECT) for preoperative parathyroid tumor (PT) localization in primary hyperparathyroid (PHP) patients. Methods A retrospective review was carried out of the medical records of all PHP patients who underwent ultrasound (US), Tc-99m sestamibi noncontrast single photon emission computed tomography (CT-MIBI), DECT and parathyroidectomy at a single center. Results The sensitivities and accuracies for preoperative PT localization in the 97 patient study population were: US 40% and 93%, CT-MIBI 64.0% and 97%, and DECT 84% and 96%, respectively. In the one third of the study population that did not localize preoperatively with CT-MIBI and US, DECT correctly localized a PT in 21 cases (66%). DE-CT and US correctly localized a PT in 86% of cases, and only 5 (8%) of the cases that were accurately localized by a combination of CT-MIBI and US were not identified by DE-CT. Conclusions DECT should be utilized as a first line preoperative PT localization study in PHP patients, and is also a sensitive salvage localization test.

PURPOSE Patients with asymptomatic primary hyperparathyroidism might have a positive Tc-sestamibi parathyroid but do not meet criteria for surgical resection when the disease is diagnosed. However, many of these asymptomatic patients will become symptomatic or meet criteria for surgery later on. The aim of this study was to determine whether a positive sestamibi scan can precede future surgical eligibility in these patients. METHODS This retrospective study reviewed the records of 94 asymptomatic patients who had hyperparathyroidism and underwent Tc-sestamibi study with SPECT/CT imaging. Among them, 35 patients, including 12 with positive and 23 with negative sestamibi parathyroid scan, did not meet the criteria for surgery at the time of imaging, and follow-up record for at least 1 year was assessed on these patients. The imaging findings and the eligibility for surgery at the end of the follow-up were compared. RESULTS With a median follow-up of 2.4 years (range, 1-4 years), among all 35 patients who were initially not eligible for surgery, 6 of 12 patients with a positive sestamibi scan became eligible for surgery, whereas 20 of 23 patients with negative scans remained ineligible for surgery. CONCLUSIONS Positive parathyroid SPECT/CT predicted a higher possibility of meeting surgical criteria over time in asymptomatic hyperparathyroidism patients who are not surgery eligible at the time of presentation.