Preoperative thyroid ultrasound is indicated in patients undergoing parathyroidectomy for primary hyperparathyroidism

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

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

Utility of 99mTc-Sestamibi Single-Photon Emission Computed Tomography (SPECT)/CT Single Imaging Strategy in the Preoperative Localization of Parathyroid Adenoma

Background Primary hyperparathyroidism is an endocrinopathy associated with dysregulated calcium homeostasis. The most common etiology is a parathyroid adenoma most definitely managed via a parathyroidectomy. The two main surgical approaches include a minimally invasive parathyroidectomy (MIP) and open four-gland exploration (4-GE). MIP is the preferred operative strategy since it is associated with less postoperative complications. Accurate preoperative imaging is essential in informing the optimal approach to surgery. MIP is only considered if adenoma is able to be localized precisely. The most commonly used imaging modality includes ultrasound and sestamibi single-photon emission computed tomography (SPECT)/CT, either as a single or combination strategy. Other options include MRI, PET, and 4D CT. There is no universally accepted preoperative imaging strategy. The literature is discordant and recommendations proposed by existing guidelines are incongruous. Objectives This study aimed to evaluate currently utilized preoperative parathyroid imaging modalities at our institution and correlate them with surgical and histological findings to determine the most efficient imaging strategy to detect adenomas for our patient cohort. This will ultimately guide the best surgical approach for patients receiving parathyroidectomies. Methods This is a retrospective observational study of all patients undergoing first-time surgery for biochemically proven primary hyperparathyroidism at our institution over the past five years. Multiple data points were collected including modality of preoperative disease localization, operation type, final histopathology, biochemical investigations, and cure rate. Patients were categorized into one of three groups based on the method of disease localization. Results A total of 244 patients had parathyroidectomies performed at our institution in the past five years from January 2018 to December 2022. Ninety-six percent (n=235) of all patients received dual imaging preoperatively with SPECT/CT and ultrasound performed on the same day and therefore included in this study. A total of 64.3% (n=151) underwent MIP. Eighty percent (n=188) of all histopathology revealed adenomas and 26.8% (n=63) of patients had adenoma localized on SPECT/CT only (sensitivity: 58.1%, specificity: 71%, and positive predictive value {PPV}: 85.7%). A total of 9.8% (n=23) had adenoma localized on ultrasound only (sensitivity: 15.6%, specificity: 73.3%, and PPV: 65.2%). A total of 45.1% (n=106) were dual localized on both SPECT/CT and ultrasound (sensitivity: 75.6%, specificity: 46.6%, and PPV: 84.9%). The cure rate was 91.5% in the dual-localized group, 86% in the dual-unlocalized group, and 96.5% when localized with SPECT/CT alone. Conclusion A dual-imaging modality with SPECT/CT and ultrasound should remain the first-line imaging strategy. This approach has higher sensitivity rates and poses no inherent patient or surgical-related risks. Patients with disease unlocalized on SPECT/CT alone had a positive predictive value, specificity, and likelihood ratio for adenoma detection comparable to dual-localized patients. Therefore, SPECT/CT alone is sufficient for directing MIP in the presence of a negative ultrasound.

Papillary thyroid carcinoma prevalence and its predictors in patients with primary hyperparathyroidism

Aim: Papillary thyroid carcinoma (PTC) and primary hyperparathyroidism (PHPT) are among the most common endocrine diseases. Although it has been shown that hyperparathyroidism may be associated with various cancers, the question of whether there is an association between hyperparathyroidism and PTC remains controversial. To evaluate the incidence of concomitant PTC among patients with PHPT and to identify possible risk factors for the development of PTC in these patients. Material and Method: The data of 543 patients who had been operated on due to PHPT in our institution were reviewed retrospectively. Patients who underwent thyroid surgery in conjunction with parathyroidectomy and patients whose diagnosis of PTC was confirmed histopathologically were compared in terms of their clinical, biochemical, and histopathological features. The prevalence of PTC found in patients with PHPT was compared with national rates to estimate standardized incidence ratios (SIRs). Results: Of the 456 PHPT patients enrolled in the study, 281 (61.6%) had concomitant thyroid nodules on thyroid ultrasonography, and PTC was detected in 53 (11.6%) patients during their thyroid surgeries. Compared to the general population, the incidence of papillary thyroid cancer was increased in both women and men with PHPT (SIR: 272.2, 95% CI: 201.6-360.0, p

Dual-Time-Point 18F-Fluorocholine PET/CT Improves Characterization of Thyroid Nodules in Patients Referred for Primary Hyperparathyroidism: A Proof of Concept Study

PURPOSE

Thyroid nodules frequently coexist with primary hyperparathyroidism (pHPT). Because of the increasing use of 18F-fluorocholine (18F-FCH) PET/CT in patients with pHPT, evaluation of its clinical utility for thyroid nodules characterization in this population is of paramount importance. Herein, we investigate the value of dual-point 18F-FCH PET/CT in the diagnosis of thyroid cancer in patients referred for pHPT imaging who have thyroid nodules.

PATIENTS AND METHODS

All pHPT patients who underwent a dual-time point 18F-FCH PET/CT (at 5 and 60 minutes postinjection) between July 2019 and December 2020 were analyzed. Only those with a thyroid nodule greater than 10-mm and pathological analysis (criterion standard) were included. Nodule-to-thyroid SUVmax ratio was calculated at the 2 study points, as well as the 18F-FCH washout index (WO%).

RESULTS

Twenty-seven patients (32 nodules) were included in this study. The final diagnoses were as follows: 27 benign nodules including 2 NIFTPs (noninvasive follicular thyroid neoplasm with papillary-like nuclear features) and 5 cancers of follicular origin. Early uptake ratio was significantly higher in malignant lesions than in benign nodules (P = 0.0008). Thyroid cancers were also characterized by a marked 18F-FCH washout index (WO% benign vs cancer: 2.9% ± 4.1% vs 45.5% ± 13.4%, P = 0.0001). Using a WO% threshold of 22.1%, 25/27 benign nodules and 5/5 malignant lesions were accurately classified (sensitivity of 100%, specificity of 92.6%, positive predictive value of 71.4%, and negative predictive value of 100%). The false-positive findings were related to the 2 NIFTPs that share similarities with thyroid cancer.

CONCLUSIONS

Our preliminary results suggest to perform a dual-time-point PET/CT acquisition protocol in pHPT patients with uncharacterized centimeter thyroid nodules. However, the real impact of these promising results should be assessed by prospective studies on a larger cohort of patients.

Increased thyroid malignancy in patients with primary hyperparathyroidism

BACKGROUND

Multiple studies have reported the increased incidence of thyroid cancer in patients with primary hyperparathyroidism (PHPT). However, the underlying risk factors of concomitant thyroid cancer in patients with PHPT remain unknown. The primary aim of this study was to examine the records of patients with PHPT to identify characteristics that correlated with the presence of coexisting thyroid nodules, and which may have an implication for the prediction of thyroid cancer.

METHODS

Medical records of consecutive patients with PHPT (n = 318) were reviewed from January 2010 to September 2020 in two tertiary medical centers in China. Patient clinicopathological and biological data were collected and analyzed.

RESULTS

Of a total of 318 patients with PHPT, 105 (33.0%) patients had thyroid nodules and 26 (8.2%) patients were concomitant with thyroid cancer. A total of 38 thyroid nodules taken from 26 patients were pathologically assessed to be well-differentiated papillary thyroid carcinoma (PTC), with 81% being papillary thyroid microcarcinoma (PTMC). In 79% (30/38) of these cancers, thyroid nodules were considered suspicious following preoperative ultrasound. Multinomial logistic regression analysis revealed that female gender was associated with increased risk of thyroid nodules (OR = 2.13, 95% CI: 1.13-3.99, P = 0.019), while lower log-transformed parathyroid hormone levels were an independent predictor of thyroid cancer in patients with PHPT (OR = 0.50, 95% CI: 0.26-0.93, P = 0.028).

CONCLUSION

In conclusion, we observed a relatively high prevalence of thyroid cancer in our cohort of Chinese patients with PHPT. Evaluation of thyroid nodules by preoperative ultrasound may be advisable in patients with PHPT, particularly for females and patients with modestly elevated serum parathyroid hormone levels.

A rare coexistence of parathyroid adenoma and medullary and papillary thyroid carcinoma

The combination of parathyroid adenoma, medullary thyroid carcinoma (MTC), and papillary thyroid carcinoma (PTC) has been reported occasionally, but it has now been recognized more often through effective evaluations. However, the etiology and risk factors remain unclear, so we discuss them in this article. Here, we report the case of a 64-year-old woman with parathyroid adenoma, MTC, and PTC diagnosed incidentally. This woman was admitted to the Xingtai People's Hospital affiliated to Hebei Medical University for an apparently aggravating symptom of hypodynamia. Her past medical history included diabetes and a left nephrolith. Upon admission, her bloodwork showed hypercalcemia, hypophosphatemia, and elevated serum parathyroid hormone. Subsequently, the sonographic findings revealed dominant nodules in both the right and left lobes with a left inferior suspected parathyroid adenoma. The patient underwent fine needle aspiration (FNA) of the bilateral thyroid lobes, the results of which were both thyroid carcinoma. Therefore, a thyroidectomy, a neck dissection, and the excision of a suspected parathyroid adenoma were performed. A histological examination revealed a combination of parathyroid adenoma, MTC, and PTC. Her serum calcium and parathyroid hormone levels returned to the normal range after the surgery. Our case highlighted the fact that even though the concurrent existence of parathyroid adenoma, MTC, and PTC is rare, the diagnosis of this coexistence should be considered in primary hyperparathyroidism (PHPT). To avoid repeat surgeries, patients with coexisting diseases should be screened cautiously. Therefore, we recommend a preoperative check of the calcium levels in patients with thyroid cancer and a preoperative thyroid check in all patients with PHPT.

Surgeon-performed Ultrasound for Primary Hyperparathyroidism

The role of preoperative parathyroid imaging continues to evolve. This study evaluated whether surgeon-performed ultrasound (U/S) obviates the need for other imaging studies and leads to a focused exploration with a high degree of surgical success. From July 2010 to February 2012, 200 patients presenting with nonfamilial primary hyperparathyroidism underwent neck U/S in the surgeon's office. The U/S interpretation was classified as Class 1 if an adenoma was identified with high confidence, Class 2 if a possible but not definite enlarged gland was imaged, and Class 0 (zero) if no adenoma was identified. The findings were correlated with subsequent intra-operative findings. There were 144 Class 1 U/Ss (72%); of 132 patients coming to surgery, 96.2 per cent had surgical findings concordant with preoperative U/S and all had apparent surgical cure. Twenty-nine patients (14.5%) had Class 2 U/S; the 31 per cent confirmed false-positives in this group were usually colloid nodules. Fourteen of 27 with Class 0 U/S underwent surgery after being offered dynamically enhanced computed tomography scan. All 200 patients were apparent surgical cures. Surgeon-performed U/S is expedient, convenient, inexpensive, and accurate. A clearly identified adenoma can safely lead to a focused limited exploration and avoid additional imaging 93 per cent of the time.

Long-term therapeutic outcomes of papillary thyroid carcinoma with concomitant hyperparathyroidism: A single center case-control study

Background

Papillary thyroid carcinoma occasionally presents with concomitant hyperparathyroidism; however, the clinical significance has not been well established. This study aimed to evaluate the long-term cancer prognosis following a multimodality therapy.

Methods

We conducted a case-control study using prospectively maintained data from a medical center thyroid cancer database between 1980 and 2013. The study cohort comprised patients with concomitant papillary thyroid carcinoma and hyperparathyroidism. Patients with papillary thyroid carcinoma only were matched using the propensity score method. Therapeutic outcomes, including the non-remission rate of papillary thyroid carcinoma and patient mortality, were compared.

Results

We identified 27 study participants from 2537 patients with papillary thyroid carcinoma, with 10 patients having primary hyperparathyroidism and 17 having renal hyperparathyroidism. Eighty-five percent of the cohort was found to have tumor–node–metastasis stage I disease. During a mean follow-up of 7.7 years, we identified 3 disease non-remission and 4 mortality events. The non-remission risk did not increase (hazard ratio [HR], 1.66; 95% confidence interval [CI], 0.43–6.40; p = 0.47); however, the overall mortality risk significantly increased (HR, 4.43; 95% CI, 1.11–17.75; p = 0.04). All mortality events were not thyroid cancer related, including two identified cardiovascular diseases.

Conclusions

Patients with papillary thyroid carcinoma who present with concomitant hyperparathyroidism are usually diagnosed at an early cancer stage with compatible therapeutic outcomes. However, hyperparathyroidism-related comorbidity may decrease long-term survival.

The role of ultrasound in the diagnosis of the coexistence of primary hyperparathyroidism and non-medullary thyroid carcinoma

BACKGROUND

The coexistence of primary hyperparathyroidism(PHPT) and papillary thyroid cancer(PTC) is a known entity; it is a rare and complicated setting for diagnostic imaging.

METHODS

After reviewing clinical data of 112 patients who had been treated for PHPT in our facility between January 2015 and December 2017, we identified 7 non-medullary thyroid carcinoma (NMTC) (6.25%). All of them had taken an ultrasound scan and undergone operation. In addition, we have also reviewed relevant reports from other facilities addressing PHPT and NMTC (Mainly PTC).

RESULTS

The 7 NMTCs were all pathologically confirmed PTC in our study, and they consisted of 6 parathyroid adenomas and 1 parathyroid carcinoma. 1 of the 7 patients had 2 malignant PTC nodules with neck lymph node metastasis, the rest 6 had single-focal PTC. Processing previous report data supported an association between PHPT and PTC, although the coexistence of PHPT and PTC is rare, but it does happen. Ultrasound, as an effective examination, would help screen the simultaneous lesions before operation, thus to avoid second surgery if not observed for both diseases at initial stage.

CONCLUSIONS

Ultrasound is a necessary choice for preoperative localization, because it has the ability to simultaneously examine the thyroid and parathyroid lesions.

Diagnosis performance of 99mTc-MIBI and multimodality imaging for hyperparathyroidism

This study aimed to examine the diagnosis performance of ^99mTc-methoxyisobutylisonitrisonitrile (^99mTc-MIBI) and multimodality imaging [ultrasound, single-photon emission computed tomography/computed tomography (SPECT/CT)] for hyperparathyroidism (HPT). From Nov. 2009 to Dec. 2015, clinical data of a total of 43 HPT patients (16 males and 27 females; 26-70 years old, average age: 51.60±10.66 years old) were retrospectively analyzed. Among them, 19 patients with primary hyperparathyroidism (PHPT) underwent ^99mTc-MIBI planar imaging, 24 [15 with PHPT and 9 with secondary hyperparathyroidism (SHPT)] underwent SPECT/CT hybrid imaging, and 41 (33 with PHPT and 8 with SHPT) had neck ultrasound imaging. Final diagnosis was determined by pathological examination after surgery. The positive rate was compared between different imaging modalities, and the correlation analysis was conducted between imaging results and lesion size or serum parathyroid hormone (PTH) level. The results showed that the total positive rates of ^99mTc-MIBI imaging, ultrasound, and the two combined imaging in the 43 HPT cases were 90.70% (39/43), 58.54% (24/41), and 100% (41/41), respectively. According to lesion numbers, the positive rates were 79.10% (53/67), 53.23% (33/62), and 88.71% (55/62), respectively. SPECT/CT hybrid images were positive in all the 24 patients who underwent this examination. The mean maximum diameters of the lesions in ^99mTc-MIBI positive and negative patients were 1.96±0.95 cm and 1.36±0.67 cm respectively, with statistically significant difference noted (P=0.03). The T/NT of ^99mTc-MIBI imaging at the early phase was correlated positively with serum PTH level (r=0.40, P=0.01). The T/NT of ^99mTc-MIBI imaging at both the early phase and the delay phase was correlated positively with lesion size (r=0.51, and r=0.45, respectively; P<0.01 for both). It was concluded that ^99mTc-MIBI imaging presents significant value for location diagnosis of HPT, especially when combined with SPECT/CT hybrid imaging or ultrasound. The ^99mTc-MIBI uptake correlates positively with serum PTH level and lesion size.

Concomitant thyroid disease and primary hyperparathyroidism in patients undergoing parathyroidectomy or thyroidectomy

BACKGROUND

Thyroid abnormalities have been found intraoperatively during parathyroidectomy and have resulted in concomitant thyroidectomy. The identification of concomitant disease is important prior to primary operation in order to minimize reoperations. This study investigates the incidence of concomitant primary hyperparathyroidism (PHPT) and thyroid nodular disease in patients undergoing thyroidectomy or parathyroidectomy.

METHODS

We performed a retrospective review of prospectively gathered data for 621 patients who underwent thyroidectomy, parathyroidectomy, or both at Tulane Medical Center. Information obtained included initial referral, initial thyroid stimulating hormone (TSH), initial parathyroid hormone (PTH), fine needle aspiration (FNA) results, ultrasound results, type of operation performed, final diagnosis, and final pathology.

RESULTS

Among the 400 patients referred primarily for thyroid disease, 13.50% underwent a thyroidectomy and parathyroidectomy (PTX) simultaneously and 10.75% received a final diagnosis of thyroid and concomitant parathyroid disease. Among the 103 patients referred primarily for parathyroid disease, 26.21% underwent a PTX and thyroidectomy and 24.27% received a final diagnosis of both thyroid and parathyroid disease. Patients referred primarily for parathyroid disease were more likely to receive a final diagnosis of both parathyroid and thyroid disease and were more likely to undergo a combined operation.

CONCLUSIONS

Concomitant thyroid and parathyroid disease occur and preoperative analysis is important to avoid increased complications from reoperations.

Serum Calcium and Risk of Nonmedullary Thyroid Cancer in Patients with Primary Hyperparathyroidism

Background

Clinical cases of nonmedullary thyroid carcinoma (NMTC) in combination with primary hyperparathyroidism (PHPT) have been reported occasionally. However, the clinical characteristics and risk factors of concomitant NMTC in PHPT patients remain unclear. This study aimed to assess the association between PHPT and NMTC, and evaluate the clinical characteristics and risk factors of NMTC in Chinese patients with PHPT.

Material/Methods

This was a retrospective cohort analysis. We reviewed the medical records of 155 patients who underwent surgery for PHPT in two large medical centers in China between 2009 and 2014. The clinical manifestations, biochemical abnormalities, and histological characteristics of PHPT patients were analyzed.

Results

Of the 155 patients with PHPT, 58 patients (37.4%) had thyroid nodules and 12 patients (7.7%) were ill with concomitant NMTC. PHPT patients with NMTC demonstrated significantly lower preoperative serum calcium levels compared to PHPT patients with benign thyroid nodules (p<0.05). A significantly negative association between preoperative serum calcium levels and the presence of NMTC was found in PHPT patients (p<0.05). Furthermore, ROC analysis revealed that albumin-corrected serum calcium levels <2.67 mmol/L had good capacity to differentiate the PHPT patients with NMTC from those with benign thyroid nodules.

Conclusions

Compared with the reported much lower prevalence of thyroid carcinoma in the general population, our results suggest that PHPT might be a risk factor for the malignancy of thyroid nodules; a lower level of serum calcium may predict the existence of NMTC in PHPT patients with thyroid nodules.

A Pilot Comparison of 18F-fluorocholine PET/CT, Ultrasonography and 123I/99mTc-sestaMIBI Dual-Phase Dual-Isotope Scintigraphy in the Preoperative Localization of Hyperfunctioning Parathyroid Glands in Primary or Secondary Hyperparathyroidism: Influence of Thyroid Anomalies

We compared (18)F-fluorocholine hybrid positron emission tomography/X-ray computed tomography (FCH-PET/CT) with ultrasonography (US) and scintigraphy in patients with hyperparathyroidism and discordant, or equivocal results of US and (123)I/(99m)Tc-sesta-methoxyisobutylisonitrile (sestaMIBI) dual-phase parathyroid scintigraphy. FCH-PET/CT was performed in 17 patients with primary (n = 11) lithium induced (n = 1) or secondary hyperparathyroidism (1 dialyzed, 4 renal-transplanted).The reference standard was based on results of surgical exploration and histopathological examination. The results of imaging modalities were evaluated, on site and by masked reading, on per-patient and per-lesion bases.In a first approach, equivocal images/foci were considered as negative. On a per-patient level, the sensitivity was for US 38%, for scintigraphy 69% by open and 94% by masked reading, and for FCH-PET/CT 88% by open and 94% by masked reading. On a per-lesion level, sensitivity was for US 42%, for scintigraphy 58% by open and 83% by masked reading, and for FCH-PET/CT 88% by open and 96% by masked reading. One ectopic adenoma was missed by the 3 imaging modalities. Considering equivocal images/foci as positive increased the accuracy of the open reading of scintigraphy or of FCH-PET/CT, but not of US. FCH-PET/CT was significantly superior to US in all approaches, whereas it was more sensitive than scintigraphy only for open reading considering equivocal images/foci as negative (P = 0.04). FCH uptake was more intense in adenomas than in hyperplastic parathyroid glands. Thyroid lesions were suspected in 9 patients. They may induce false-positive results as in one case of oncocytic thyroid adenoma, or false-negative results as in one case of intrathyroidal parathyroid adenoma. Thyroid cancer (4 cases) can be visualized with FCH as with (99m)Tc-sestaMIBI, but the intensity of uptake was moderate, similar to that of parathyroid hyperplasia.This pilot study confirmed that FCH-PET/CT is an adequate imaging tool in patients with primary or secondary hyperparathyroidism, since both adenomas and hyperplastic parathyroid glands can be detected. The sensitivity of FCH-PET/CT was better than that of US and was not inferior to that of dual-phase dual-isotope (123)I/(99m)Tc-scintigraphy. Further studies should evaluate whether FCH could replace (99m)Tc-sestaMIBI as the functional agent for parathyroid imaging, but US would still be useful to identify thyroid lesions.

Is primary hyperparathyroidism a risk factor for papillary thyroid cancer? An exemplar study and literature review

Introduction Primary hyperparathyroidism (PHPT) is associated with several cancer types, including papillary thyroid carcinoma (PTC). Objective To explore further the relation between PHPT and PTC. Methods By considering patients with PHPT as extra-suspicious for PTC, we studied an exemplar group of patients with PHPT with a small (≤1 cm) thyroid nodule, which was negative in preoperative cytologic examination. During parathyroidectomy, a frozen section biopsy of the thyroid nodule confirmed PTC, as did the final surgical specimen, revealing that the preoperative cytology was false-negative. Additionally, relevant reports retrieved from the English literature addressing thyroid cancer and hyperparathyroidism were reviewed and processed. Results Four patients with PHPT were studied. Three had a multifocal thyroid disease, and three had neck lymph node metastasis. Processing previous report data supported an association between PHPT and PTC. Although thyroid nodularity among patients with PHPT was similar to the general population, PTC incidence was higher. This was true also for patients with secondary hyperparathyroidism. Conclusions This study emphasized that PHPT should be considered as a noteworthy risk factor for PTC. Fine needle aspiration of a thyroid nodule is the most valuable diagnostic procedure for thyroid cancer. Yet, false-negative results were reported in up to 10% of cases, especially in small, subcentimeter nodules. In line with our data and the literature, patients with PHPT should have both a detailed ultrasound addressing the thyroid and cytology of any thyroid nodule, including small subcentimeter lesions. Moreover, surgical flexibility, allowing intraoperative thyroid nodule sampling, should be considered even for "innocent" nodules.

Association of synchronous medullary and papillary thyroid carcinomas with primary hyperparathyroidism: first case report and literature review

OBJECTIVE

We report a case of a patient with symptomatic primary hyperparathyroidism who was found, through a thorough radiological investigation, to also have papillary and medullary thyroid carcinomas.

CASE REPORT

A 59-year-old female was diagnosed with primary hyperparathyroidism. A further radiological investigation found suspicious areas within both thyroid lobes that were later diagnosed as foci of papillary and medullary thyroid carcinomas. Appropriate treatment was commenced. Reports of similar occurrences of synchronous thyroid and parathyroid pathologies are discussed.

CONCLUSION

To our knowledge, this is the first reported case of two synchronous thyroid cancers occurring in the context of primary hyperparathyroidism. We strongly recommend a thorough radiological investigation of all patients with primary hyperparathyroidism to prevent missing concurrent thyroid cancers.

The relationship between secondary hyperparathyroidism and thyroid cancer in end stage renal disease: a population based cohort study

OBJECTIVES

We conducted a retrospective cohort study to investigate the risk of cancer in end stage renal disease (ESRD) patients with secondary hyperparathyroidism (HPT).

PATIENTS AND METHODS

This study investigated the elevated overall cancer risk in ESRD patients with secondary HPT in Taiwan. We used a population-based retrospective cohort consisting of original claims data of 1 million beneficiaries randomly sampled from the Taiwan National Health Insurance Research Database (NHIRD). We calculated the hazard ratios (HRs) and 95% confidence intervals (CIs) of cancer in the ESRD with secondary HPT and comparison cohorts, using the Cox proportional hazards regression model.

RESULTS

We observed that ESRD patients with secondary HPT exhibited a 10.1-fold increased risk of thyroid cancer than did ESRD patients without this parathyroid complication, after adjusting for comorbidities (95% confidence interval=1.12-91.0).

CONCLUSION

These phenomena indicate that ESRD patients with secondary HPT are at greater risk of thyroid cancer. Physicians should be alert for occult thyroid cancer in ESRD patients with secondary HPT.

Ultrasound for localization in primary hyperparathyroidism

OBJECTIVE

To evaluate the capability of ultrasound for preoperative localization in primary hyperparathyroidism.

STUDY DESIGN

Prospective study.

SETTING

Multi-institutional Midwest Head and Neck Cancer Consortium.

SUBJECTS AND METHODS

Two hundred twenty patients who underwent preoperative localization and had parathyroid surgery were evaluated. The findings of preoperative localization studies were correlated with surgical findings.

RESULTS

Preoperative ultrasonography, sestamibi scintigraphy, or both were obtained in 77%, 93%, and 69% of the patients, respectively. Preoperative ultrasonography and sestamibi scintigraphy localized an abnormality in 71% and 79% of patients, respectively. At the time of surgery, the localization by ultrasound was accurate in 82%. The accuracy of localization was similar for sestamibi scintigraphy (85%). In patients with inaccurate ultrasound localization, the sestamibi scintigraphy correctly identified the site of disease in only 45%. In patients with a nonlocalizing ultrasound, sestamibi scintigraphy was able to localize disease in only 47%, with 2 being in the mediastinum.

CONCLUSIONS

Ultrasonography is an acceptable initial localization study for patients with primary hyperparathyroidism. In patients with nonlocalizing ultrasound, sestamibi scintigraphy should be obtained, but can be expected to detect an abnormality in less than 50% of patients.