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.     

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)     

Parathyroid Hormone Level Changes Following Radioiodine Therapy for Thyroid Cancer: A Prospective Observational Study

ObjectiveOur objective was to analyze the effect of radioiodine (RAI) therapy on parathyroid hormone (PTH) secretion.MethodsA total of 137 patients were included and divided into 2 groups based on pretherapy PTH levels. The residual thyroid tissue volume was classified into 4 grades (0-3), and a value of 0 indicated that there was no apparent residual tissue. We analyzed the PTH level changes among different time points in each group and the factors that could predict the PTH level changes.ResultsIn 113 patients with normal parathyroid gland function, the PTH level at baseline, 1 day, 7 days, 1 month, 3 months, and 6 months after RAI therapy did not show any significant difference; in 24 patients with decreased parathyroid gland function, the level of PTH immediately decreased after the implementation of RAI therapy but gradually returned to a pre-RAI therapy level within 6 months. On the seventh day after therapy, the mean value of PTH in patients with a residual thyroid tissue volume of extent of 0/1 was 8.0 ± 2.3 pg/mL, which was significantly higher than that in patients with a residual thyroid tissue volume of extent of 2/3 (P = .011). Similar phenomena were observed 1 month, 3 months, and 6 months after therapy.ConclusionRAI therapy had a significant transient adverse effect on parathyroid gland function in patients with decreased PTH secretion pretherapy, and the extent was associated with the amount of residual thyroid tissue.     

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)     

Parathyroid Cystic Adenoma: A Systematic Review and Meta-Analysis

ObjectiveTo review diagnostic imaging modalities for parathyroid cystic adenomas (PCA). Since PCAs are a rare (0.5%-1%) subclass of parathyroid adenomas, and due to their cystic component, imaging modalities known to be efficient for diagnosing solid adenomas might fail in localizing them.MethodsWe conducted a systematic review using the PubMed and Cochrane databases for English articles on PCAs published between 1995 and 2020. A meta-analysis of the retrieved data was performed.ResultsOverall, 39 studies, reporting on a total of 160 patients, were included in the analysis. Two thirds (68%) of the patients were female, with a mean age of 53.9 years. A single cystic adenoma was detected in 98.1% of cases. The mean blood calcium corrected for albumin level was 12.6 ± 2.7 mg/dL, and the mean parathyroid hormone level was 565.5 ± 523.8 pg/mL. The mean PCA sizes as measured by ultrasound (US), computed tomography (CT), and ex vivo measurement were 4.8 ± 3.6, 5.2 ± 3.2, and 3.5 cm, respectively. The median weight was 8.1 g. PCA was detected in 86% of US examinations; 100% of US-guided fine needle aspiration, 4-dimensional computed tomography (4D-CT), or magnetic resonance imaging examinations; and 61% of 99m-technetium sestamibi scan with single-photon emission computed tomography ((99m)Tc-SPECT). (99m)Tc-SPECT showed a significantly lower diagnostic rate than US (odds ratio, 3.589), US-guided fine needle aspiration, CT combined with 4D-CT, and the combination of US, CT, 4D-CT, and magnetic resonance imaging (P < .001).ConclusionAlthough US and 4D-CT showed a significantly high rate in diagnosing PCA, (99m)Tc-SPECT showed a lower PCA diagnostic rate. These findings suggest that larger cystic lesions suspected as PCAs should be further evaluated using 4D-CT rather than (99m)Tc-SPECT.     

Calcium,Parathyroid Hormone,and Vitamin D in Patients with Primary Hyperparathyroidism: Normograms Developed from 10000 Cases

ObjectiveTo better define the typical and atypical biochemical profiles of patients with surgically proven primary hyperparathyroidism.MethodsIn this single-center, prospectively conducted study of consecutive patients with surgically proven primary hyperparathyroidism over a 7-year period, we analyzed serum calcium, parathyroid hormone, and 25-hydroxyvitamin D concentrations.ResultsA total of 10 000 patients were included, and more than 210 000 calcium, parathyroid hormone, and 25-hydroxyvitamin D values were evaluated. Both calcium and parathyroid hormone levels demonstrated a Gaussian distribution with the average calcium concentration being 10.9 ± 0.6 mg/dL and the average parathyroid hormone concentration being 105.8 ± 48 pg/mL. The average highest calcium and parathyroid hormone concentrations were 11.4 ± 0.7 mg/dL and 115.3 ± 50 pg/mL, respectively. At least 1 calcium value of 11.0 mg/dL was seen in 87% of patients, but only 21% had 1 or more calcium value above 11.5 mg/dL. Only 7% had a single serum calcium level reaching 12.0 mg/dL. Normocalcemic hyperparathyroidism was seen in just under 3% of patients who had identical findings at surgery. An average parathyroid hormone concentration less than 65 pg/mL was seen in 16%, with 10% of patients who had no high parathyroid hormone values. The average 25-hydroxyvitamin D concentration was 22.4 ± 9 ng/mL, with levels decreasing as calcium levels increased (P < .001); 36% had 25-hydroxyvitamin D levels below 20 ng/mL.ConclusionsPatients with PHPT present with a number of distinct biochemical profiles, but as a group, they present with a near-normal Gaussian distribution of both calcium and parathyroid hormone levels. Either serum calcium or parathyroid hormone remained normal in 13% of patients, yet the findings at surgery are similar to those of patients with elevated calcium or parathyroid hormone. Low 25-hydroxyvitamin D is an expected finding in patients with PHPT, decreasing as serum calcium levels increase. (Endocr Pract. 2011;17:384-394)     

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

ObjectiveFunctional 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.MethodsDual-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.ResultsOf 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.ConclusionHemorrhage 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.     

Diagnostic Fine-Needle Aspiration Biopsy of an Intrathyroidal Parathyroid Gland and Subsequent Eucalcemia in a Patient with Primary Hyperparathyroidism

ObjectiveTo present the clinical course of a patient with persistent primary hyperparathyroidism (PHPT) whose intrathyroidal parathyroid gland was diagnosed by ultrasound-guided fine-needle aspiration biopsy (FNAB).MethodsWe describe the clinical course and laboratory, radiographic, and microscopic findings of a patient with persistent PHPT due to an intrathyroidal cystic parathyroid gland and review the relevant literature.ResultsA 74-year-old man with PHPT (presenting serum calcium concentration, 16.2 mg/dL; intact parathyroid hormone [PTH] concentration, 341 pg/mL) had surgical excision of the right superior, right inferior, and left inferior parathyroid glands, but the left superior parathyroid gland remained unidentified. Microscopic examination revealed parathyroid hyperplasia. Technetium Tc 99m sestamibi single-photon emission computed tomography imaging showed uptake in 2 foci, 1 on each side of midline in the neck. Reoperation with attention to the left neck failed to locate another parathyroid gland. Neck ultrasonography demonstrated a complex nodule within the right lower lobe of the thyroid. Results from FNAB of the solid component were consistent with parathyroid cells, and cystic fluid PTH concentration was greater than 1800 pg/mL. Nine months later, neck ultrasonography showed a hypoechoic area located posterior to the inferior pole of the right thyroid. The patient remained eucalcemic 16 months postprocedure.ConclusionAutoinfarction of the parathyroid gland and aspiration of cystic fluid may explain resolution of hypercalcemia. Although PHPT due to functioning parathyroid cysts is rare, and PHPT due to cystic parathyroid hyperplasia has been described, this is the first case report of a patient with persistent PHPT due to a functional parathyroid cyst whose diagnosis by FNAB was followed by eucalcemia. (Endocr Pract. 2008;14:80-86)     

Falsely Elevated Plasma Parathyroid Hormone Level Mimicking Tertiary Hyperparathyroidism

ObjectiveTo report a case of misdiagnosed tertiary hyperparathyroidism attributable to heterophile antibody interference in a parathyroid hormone (PTH) assay.MethodsWe present clinical and laboratory data relative to this case and review the pertinent English-language literature.ResultsA 36-year-old woman with a functioning renal allograft, PTH excess (3, 374 pg/mL) refractory to medical therapy, and a history of renal osteodystrophy presented for consideration of a third parathyroidectomy. Remedial parathyroidectomy was performed. The PTH levels did not decline postoperatively, but the patient developed severe hypocalcemia. Reanalysis of the patient’s serum specimens was performed with (1) addition of heterophile blocking agents to the murine-based immunoassay and (2) use of a different, goat antibody-based immunoassay. The true PTH level was found to be 5 pg/mL with use of both methods.ConclusionPrevious administration of muromonab-CD3 (Orthoclone OKT3) for immunosuppression may have resulted in the development of human antimurine heterophile antibodies, causing a falsely elevated PTH result. (Endocr Pract. 2011;17:e8-e11)     

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)     

Reduced Parathyroid Hormone-Stimulated 1,25-Dihydroxyvitamin D Production in Vitamin D Sufficient Postmenoposual Women with Low Bone Mass and Idiopathic Secondary Hyperparathyroidism

ObjectiveDistinguishing secondary hyperparathyroidism (sHPT) from eucalcemic primary hyperparathyroidism (EC-pHPT) is important. The objective of this study was to measure parathyroid hormone (PTH)-stimulated production of 1α,25-dihydroxyvitamin D (1,25[OH]₂D) in early postmenopausal patients with idiopathic sHPT, who also fit the criteria for EC-pHPT, compared to age-matched controls.MethodsIn this pilot case-control study, postmenopausal women aged 44 to 55 years with normal serum calcium (Ca), glomerular filtration rate (GFR) ≥65 mL/min, and 25-hydroxyvitamin D (25[OH]D) ≥75 nmol/L (30 ng/mL) were given an 8 hour infusion of PTH(1-34), 12 pmol/kg/h. Patients (n = 5) had elevated PTH, normal 1,25(OH)₂D, and no hypercalciuria. Controls (n = 5) had normal PTH. At baseline, 4, and 8 hours, serum Ca, creatinine (Cr), phosphorus (P), 1,25(OH)₂D, fibroblast growth factor (FGF23), and 24,25(OH)₂D as well as urine Ca, P, Cr, and cAMP/GFR were measured. The fractional excretion of calcium (FeCa) and tubular reabsorption of phosphorus (TMP)/GFR were calculated.ResultsPatients had lower 1,25(OH)₂D levels (± SD) than controls at 4 (39.8 ± 6.9 versus 58.8 ± 6.7; P = .002) and 8 hours (56.4 ± 9.2 versus 105 ± 2.3; P = .003) of PTH infusion, attenuated after adjusting for higher body mass index (BMI) in patients (P = .05, .04), respectively. The 24,25(OH)2D levels were lower in patients than controls (1.9 ± 0.6 versus 3.4 ± 0.6, respectively; P = .007). No differences were seen in serum Ca or P, urine cAMP/GFR, TRP/GFR, FeCa, or PTH suppression at 8 hours (patients 50%, controls 64%).ConclusionVitamin D sufficient patients who fit the criteria for EC-pHPT had reduced PTH-stimulated 1,25(OH)₂D compared to controls, partially attributable to their higher BMI. Other causes of reduced 1,25(OH)₂D production ruled out were excessive catabolism of vitamin D metabolites, elevated FGF23, and CYP27B1 mutation. Elevated BMI and idiopathic reduced PTH-stimulated 1,25(OH)₂D production should be considered in the differential of sHPT. (Endocr Pract. 2013;19:91-99)     

Association Between Aldosterone and Parathyroid Hormone Levels in Patients With Adrenocortical Tumors

ObjectivePatients with primary aldosteronism (PA) can present with high PTH levels and negative calcium balance, with some studies speculating that aldosterone could directly stimulate PTH secretion. Either adrenalectomy or mineralocorticoid receptor blockers could reduce PTH levels in patients with PA. The aim of this study was to assess the relationship between aldosterone levels and parathyroid hormone (PTH)-vitamin D-calcium axis in a cohort of patients with PA, compared with patients with nonsecreting adrenocortical tumors in conditions of vitamin D sufficiency.MethodsWe enrolled a series of 243 patients retrospectively, of whom 66 had PA and 177 had nonsecreting adrenal tumors, and selected those with full mineral metabolism evaluation and 25(OH) vitamin D levels >20 ng/mL at the time of initial endocrine screening. The final cohort was composed of 26 patients with PA and 39 patients, used as controls, with nonsecreting adrenal tumors. The relationships between aldosterone, PTH levels, and biochemistries of mineral metabolism were assessed.ResultsAldosterone was positively associated with PTH levels (r = 0.260, P < .05) in the whole cohort and in the PA cohort alone (r = 0.450; P = .02). In the multivariate analysis, both aldosterone concentrations and urinary calcium excretion were significantly related to PTH levels, with no effect of 25(OH) vitamin D or other parameters of bone metabolism.ConclusionPTH level is associated with aldosterone, probably independent of 25(OH) vitamin D levels and urinary calcium. Whether aldosterone interacts directly with the parathyroid glands remains to be established.     

Vitamin D,Parathyroid Hormone,and Heart Failure in A Chinese Elderly Population

ObjectiveHeart failure (HF) is a major cause of morbidity and mortality worldwide. Low vitamin D status has been shown to be associated with increased risk of developing cardiovascular disease. In this study, we examined the association between vitamin D and parathyroid hormone (PTH) levels and HF in and elderly population in China.MethodsA population-based cross-sectional study was conducted in the spring of 2013 among 2,047 community-dwelling healthy individuals, aged 60 to 101 years. 25-Hydroxyvitamin D (25[OH]D) was measured using a chemiluminescence assay. PTH levels were measured with an electrochemiluminescence immunoassay.ResultsA total of 2,047 participants, including 1,121 women (54.7%), were evaluated in 2013. The median concentrations of serum 25(OH)D and PTH for the entire group were 16.1 ng/mL and 41.5 pg/mL, respectively. Serum 25(OH)D and PTH levels were associated with serum N-terminal pro-brain natriuretic peptide levels and left ventricular ejection fraction in a multivariate adjusted linear regression analysis (P < .05). In logistic regression analyses, serum 25(OH)D and PTH levels were associated with a risk of HF in single and multiple regression models (P < .05). Compared with patients with 25(OH)D levels between 30.0 and 44.9 ng/mL, patients with 25(OH)D levels less than 10 ng/mL had a higher mean hazard ratio for HF (2.88; 95% confidence interval, 1.59 to 4.38).ConclusionSerum 25(OH)D and PTH levels are independently associated with risk of HF in a Chinese elderly population. (Endocr Pract. 2014;21:30-40)     

A Parathyroid Hormone–Guided Calcium and Calcitriol Supplementation Protocol Reduces Hypocalcemia-Related Readmissions Following Total Thyroidectomy

ObjectiveTo determine the effect of a 4-hour postoperative serum parathyroid hormone (PTH)–guided calcium (Ca) and calcitriol supplementation protocol on the incidence of hypocalcemia and hospital readmissions in patients undergoing total thyroidectomy.MethodsThis was a single-institution, retrospective chart review of patients who underwent total thyroidectomy; 148 and 389 of the patients underwent surgery prior to and after the protocol implementation, respectively. The risk of hypocalcemia was stratified as low (PTH level of >30 pg/mL), medium (15-30 pg/mL), and high (<15 pg/mL), using serum PTH values obtained 4 hours postoperatively. Hypocalcemia was defined as a total serum Ca level of <8 mg/dL. Baseline demographic and operative characteristics and postoperative outcome were recorded for both groups. The Fisher exact test and Wilcoxon rank sum test were used to compare the characteristics of the 2 groups. A multivariate logistic regression model was applied to account for potentially confounding variables.ResultsPostoperative hypocalcemia occurred significantly less frequently in the protocol group compared with that in the preprotocol group (10.3% vs 20.9%, P = .002). The reduction in hypocalcemia in the protocol group was observed in both patients with (16.3% vs 25.6%) and without (8.4% vs 19.3%) cervical lymph node dissection. The protocol group had a significantly lower incidence of hospital readmission events than the preprotocol group (1.0% vs 4.7%, P = .013).ConclusionCompared with a historical cohort, a PTH-guided protocol for Ca and calcitriol supplementation significantly reduces the postoperative hypocalcemia and hospital readmission rates in patients undergoing total thyroidectomy.     

The value of 99mTc-MIBI scan in the detection of malignancy potential of hypermetabolic thyroid incidentalomas of 18F-FDG PET/CT

Aim of the studyIncreasingly use of PET/CT leads to discovery of incidental findings. Hypermetabolic thyroid nodules are one of the unexpected lesions in PET/CT imaging with an increased risk of thyroid cancers. Our study aims to determine the malignant potential of incidentally detected 18F-FDG avid thyroid nodules by using Tc-99m MIBI imaging.Materials and methodsPET/CT scans were performed for nonthyroidal purposes and were evaluated for the presence of hypermetabolic thyroid nodules. Tc-99m MIBI scans and ultrasonography-guided fine needle aspiration biopsies were subsequently performed for all patients.ResultsPrimary thyroid malignancies were identified in 25% of patients with increased focal FDG uptake at definitive diagnosis. Among the patients with FDG avid thyroid nodules, Tc-99m MIBI scan showed true-positive results in all thyroid carcinomas (n:7) with a 36.3% (4/11) false-positivity rate. In three patients with indeterminate cytology results, Tc-99m MIBI scan findings were also negative. The sensitivity, specificity, positive predictive value of Tc-99m MIBI scan in predicting the malignancy of FDG-positive thyroid nodules were 100%, 77%, 63.6%, respectively.ConclusionThe implementation of ^99mTc-MIBI scan performed by dual phase and SPECT/CT modality might be a helpful cost-effective approach in addition to FNAB in patients with ¹⁸F-FDG-positive thyroid nodules and indeterminate cytology to improve the patients’ prognosis and reduce unnecessary thyroid operations with associated use of FNAB.     

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)     

术后血清PTH下降率预测甲状旁腺全切术后复发的临床价值

目的:探讨甲状旁腺全切术后PTH的监测对于预测手术后是否复发的临床价值,确定具有预测价值的术后PTH的监测时间以及下降率。方法:选取本中心2009年5月至2014年8月收治的338例继发性甲状旁腺机能亢进症(secondary hyperparathyroidism,SHPT)患者作为研究对象,所有患者手术方式均为甲状旁腺全部切除术(total parathyroidectomy,t-PTX)。分别在手术前、术后1小时、术后24小时采集患者的血液标本检测血清PTH水平,并随访至术后一年,观察PTH的下降率与复发的相关性。结果:338名例患者术前、术后1小时和术后24小时的血清PTH水平分别是(1623.2±903.2 pg/m L)、(63.4±80.8 pg/m L)、(20.9±97.0pg/m L)。所有患者术后1小时和术后24小时PTH下降率均大于50%,平均值分别为95.9±5.1%和98.8±4.8%。未复发组术后1小时PTH的下降率中位数为97.1%(63.6-99.9%),复发组术后1小时PTH下降率中位数为79.6%(48.0-96.7%),两组间术后1小时和术后24小时PTH下降率比较差异具有统计学意义(P0.01)。术后1小时及术后24小时PTH下降率的受试者工作特征曲线显示曲线下面积分别为0.907和0.897(P值均0.001)。当PTH下降率为90%时,诊断手术成功的敏感性为87.23%,特异性为88.89%。且术后1小时和术后24小时的PTH下降率基本一致,对于术后复发的临床价值无统计学差异。结论:甲状旁腺全切术后1小时血清PTH的下降率预测术后复发与术后24小时血清PTH的下降率预测手术复发的临床价值相当。     

Intérêt de la scintigraphie parathyroïdienne de soustraction dans la prise en charge de l’hyperparathyroïdie secondaire. À propos de 33 cas

Aim^99mTc-Sestamibi is used in the imaging of hyperparathyroidism in order to guide the surgical procedure and to propose methods of less invasive surgery. The aim of our study was to evaluate the efficiency of preoperative subtraction parathyroid scintigraphy (Sestamibi-^99mTc/Pertechnetate) in the management of secondary hyperparathyroidism.Patients and methodsThe records of 33 patients with renal impairment consecutively operated from 2009 to 2011 for secondary hyperparathyroidism were retrospectively reviewed. We collected data on parathyroid function, results of parathyroid scintigraphy, intraoperative findings and pathological findings.ResultsScintigraphy was positive in 32 patients by disclosing a total of 75 hyperplastic parathyroid glands. The surgical exploration of all parathyroid glands revealed 99 hyperplastic glands confirmed by histological analysis. The sensitivity of parathyroid scintigraphy was 70.7% with a specificity of 85%. Positive predictive value was 93.3%, while negative predictive value was 50%. No correlation was found between the values of parathyroid hormone (PTH) and calcemia measured preoperatively and scintigraphic results.Discussion and conclusionIn our study, the correlation of scintigraphic data with PTH and serum calcium is not statistically significant. However, owing to a high positive predictive value, the parathyroid scan should be indicated. Value of parathyroid scintigraphy extends to searching ectopic or supernumerary glands and especially in cases of persistent or recurrent hyperparathyroidism.     

Neuroendocrine Thymic Carcinoma Metastatic to the Parathyroid Gland that was Reimplanted into the Forearm in Patient with Multiple Endocrine Neoplasia Type 1 Syndrome: A Challenging Management Dilemma

ObjectiveTo describe a unique case of a metastatic thymic carcinoma to the hyperplastic parathyroid gland and to present a challenging management dilemma.MethodsOur patient is 60-year-old, intellectually disabled man with history of the multiple endocrine neoplasia type 1 (MEN1) syndrome, a surgery in 1985 for hypercalcemia with removal of one parathyroid gland, surgery in 2007 with findings of extensively necrotic well differentiated neuroendocrine carcinoma (carcinoid tumor) of the thymus. In 2012, he presented with persistent hypercalcemia (calcium level 11.7 mg/dL [range, 8.6-10.2]), and a parathyroid hormone (PTH) level of 225 pg/mL (range, 15-65 pg/mL). He underwent a repeat neck exploration with removal of 2 small inferior and a large left superior 4.5 × 2.5 × 1.5cm parathyroid glands, all of which showed hyperplasia on intraoperative frozen section. A small portion of the superior gland was reimplanted into the patient’s forearm. Final pathology showed the presence of a focus of neuroendocrine tumor within the left superior parathyroid gland with immunostain identical to the thymic carcinoma. His postoperative PTH level was 14 pg/mL and calcium 8.5 mg/dL. A positron emission tomography – computed tomography (PET-CT) and octreotide scans revealed an extensive metastatic disease within the lung, mediastinum, and bones.ResultsWe decided to leave a portion of the reimplanted parathyroid gland with possible metastatic thymic carcinoid in his forearm because of the presence a widespread metastatic disease and his intellectual disability that would result in noncompliance with calcium replacement in case of permanent hypocalcemia.ConclusionMetastatic thymic carcinoma to the parathyroid gland has never been reported in the literature. We have described the first case and presented a challenging management dilemma. (Endocr Pract. 2013;19:e163-e167)