Minimally invasive surgery for solitary parathyroid adenomas in patients with primary hyperparathyroidism: role of US with supplemental CT

[Assessment of the quality of life of patients after parathyroidectomy from standard and small access]

ОБОСНОВАНИЕ. Первичный гиперпаратиреоз (ПГПТ) — это повышение секреторной активности околощитовидных желез (ОЩЖ) вследствие их опухолевого или гиперпластического изменения. Ввиду отсутствия эффективной альтернативы лечению ПГПТ хирургический способ по-прежнему остается единственным верным тактическим решением ведения больных с установленным диагнозом ПГПТ. В работе представлены отдаленные результаты и оценка качества жизни больных, перенесших хирургическое лечение из стандартного и малого доступов. Полученные результаты показали перспективность щадящего подхода к лечению ПГПТ, обусловленного аденомой ОЩЖ.ЦЕЛЬ. Изучение эффективности хирургического лечения ПГПТ на основании оценки качества жизни больных, перенесших паратиреоидэктомию из стандартного и малого доступов.МАТЕРИАЛЫ И МЕТОДЫ. Проведено ретроспективное исследование качества жизни пациентов с ПГПТ после хирургического лечения с использованием опросника SF-36 и линейной аналоговой шкалы (ЛАШ). Статистическая обработка данных выполнена на языке программирования R с использованием пакета FMSB. Количественные параметры были представлены в виде медианы (Меdian) и интерквартильного размаха (25-й (1st Qu) — нижний квартиль и 75-й (3rd Qu) — верхний квартиль). В качестве непараметрического статистического критерия использован U-критерий Манна–Уитни (Mann–Whitney U-test), на основании которого произведен расчет p-value. Расчетные данные результатов исследования представлены в графическом виде — в виде столбчатых диаграмм, spider plot и barplot.РЕЗУЛЬТАТЫ. В настоящем исследовании приняли участие 264 пациента. Пациенты были разделены на 2 группы: ГР1 — пациенты, оперированные из доступа по Кохеру с обязательной ревизией всех 4 ОЩЖ, ГР2 — пациенты, получившие оперативное лечение из малого доступа с удалением измененной ОЩЖ, без ревизии остальных ОЩЖ. При проведении анализа качества жизни пациентов до операции статистически значимых различий в группах по показателю PF (Physical Functioning) и VT (Vitality) выявлено не было. Проведение паратиреоидэктомии из малого доступа (пациенты ГР2) статистически значимо повышало качество жизни по домену GH (General Health) и VT (Vitality). Анализ ЛАШ до операции между группами не показал статистически значимых различий, в то время как после хирургического лечения показатели по ЛАШ отличаются в сторону улучшения в ГР2.ЗАКЛЮЧЕНИЕ. Результаты, полученные в ходе исследования, показали перспективность щадящего подхода к лечению ПГПТ, обусловленного аденомой ОЩЖ, что отражено в более высоких показателях качества жизни.

The diagnostic value of 4D MRI at 3T for the localization of parathyroid adenomas

PURPOSE

The aim of this study was to assess the feasibility of four-dimensional magnetic resonance imaging (4D MRI) at 3 T for the localization of parathyroid adenomas.

MATERIALS AND METHODS

Preoperative 4D MRI scans, encompassing dynamic contrast-enhanced (DCE) sequences and non-contrast enhanced (non-CE) sequences, including a T2-weighted multipoint Dixon (T2-mDixon) sequence, with in-phase, out-phase, and water-only images, were evaluated retrospectively in 41 patients with surgically proven parathyroid lesions. Two readers who were blinded to the surgical findings independently reviewed the images in two sessions (non-CE sequences alone and non-CE + DCE sequences). The MRI localization of the suspected adenoma in each session and the consensus interpretation of the MRI images, were compared with the surgical results and interobserver agreement was assessed.

RESULTS

By interpreting the non-CE sequences alone, reader 1 correctly localized 34 parathyroid lesions (sensitivity 81.0%, positive predictive value (PPV) 87.2%), and reader 2 correctly localized 34 parathyroid lesions (sensitivity 81.0%, PPV 91.9%). With the addition of DCE sequences, reader 1 correctly identified 35 parathyroid lesions (sensitivity 83.3%, PPV 87.5%), while reader 2 correctly identified 36 parathyroid lesions (sensitivity 85.7%, PPV 92.3%). Overall, MRI detected 38 parathyroid lesions (sensitivity 90.5%, PPV 95.0%). Interobserver agreement was slightly superior in non-CE + DCE sequences compared to non-CE sequences alone (ĸ = 0.796 vs. ĸ = 0.738).

CONCLUSION

4D MRI with DCE sequencing is a reliable method for the localization of parathyroid adenomas.

A Case of Pregnancy Complicated by Primary Hyperparathyroidism Due to a Parathyroid Adenoma

BACKGROUND Primary hyperparathyroidism is most common in women during the menopause and its occurrence in pregnant women is rare. However, because neonatal mortality is associated with maternal hyperparathyroidism, early diagnosis is essential. This report describes the case of a late diagnosis of primary hyperparathyroidism in a 28-year-old pregnant woman and describes the effects on the mother and neonate. CASE REPORT During her second pregnancy, a 28-year-old woman presented with symptoms of general weakness, bone and joint pain, multiple fractures with bone deformity, muscle weakness, and gait disturbance. Due to the high risk of perinatal pathology, a cesarean section was performed. Several weeks later, she underwent thoracoscopic removal of an ectopic parathyroid gland located at the aortic arch. Hypocalcemia in the newborn infant required treatment with calcium and magnesium supplements. CONCLUSIONS This case demonstrates that primary hyperparathyroidism during pregnancy requires timely diagnosis and treatment to reduce potential maternal and fetal complications. Screening for primary hyperparathyroidism should be undertaken in pregnant women with any symptoms associated with hypercalcemia. Treatment should be individualized and includes conservative management, parathyroidectomy in the second trimester, or parathyroidectomy performed in the early postpartum period.

A retrospective review of the role of B-mode and color Doppler ultrasonography in the investigation of primary hyperparathyroidism: Features that differentiate benign from malignant lesions

Purpose

To identify the variant features encountered in parathyroid abnormalities and document those suggesting malignant change.

Materials and methods

Data were collected from a cohort of patients who underwent investigation for primary hyperparathyroidism over a 10-year period. Ultrasonographic features: shape, presence of calcification, cystic changes, heterogeneous echogenicity, vascularity, capsular thickening, local invasion, and vascularity were reviewed retrospectively and were used to correlate with final histological findings.

Results

One hundred forty-seven patients with histology and concurrent ultrasonographic scans were reviewed, and divided into benign parathyroid lesions (nodular hyperplasia (n = 44), adenoma (n = 93)) and parathyroid carcinoma (n = 10). Parathyroid carcinomas were significantly larger than benign parathyroid lesions (P = 0.030). Benign parathyroid lesions showed variant sonographic features: irregular shape (16.8%), heterogenous echogenicity (24.1%), calcification (1.5%), capsular thickening (1.5%), and cystic change (19.7%). A significantly higher proportion of parathyroid carcinomas demonstrated heterogenous echogenicity (P = 0.022), capsular thickening (P = 0.023), and infiltrative margin (P < 0.0001) than benign parathyroid lesions. Of the 137 benign parathyroid lesions, 38 (27.7%), 76 (55.5%), 23 (16.8%) were avascular, vascular, and hypervascular, respectively. Of the 10 parathyroid carcinomas, 4 (40%), 3 (30%), and 3 (30%) of lesions were avascular, vascular, and hypervascular, respectively. The vascularity of the lesions did not differ significantly between the parathyroid carcinoma and benign parathyroid lesions (P = 0.281).

Conclusion

Ultrasonographic features such as irregular shape, heterogeneous echogenicity, cystic change, and vascularity are nondiscriminatory features between benign or malignant lesions. Large lesion size together with the presence of calcification, capsular thickening, or infiltrative margin strongly raises the suspicion of a malignant parathyroid lesion, and management should be altered.

Utility of Single-Phase Computed Tomography in Identifying Parathyroid Adenomas: A Feasibility Study

OBJECTIVE

We tested the hypothesis that a single-phase neck computed tomography (CT) is not inferior to multiphase neck CT (MPNCT), ultrasound, or nuclear medicine sestamibi scan in identifying parathyroid adenomas (PAs).

METHODS

A total of 29 patients who had an MPNCT for the evaluation of a PA were identified; 11 patients met the inclusion criteria. During the 30-second arterial phase CT (APNCT), a normalized Hounsfield unit of suspected PA was compared to Hounsfield unit of a normal-appearing level I and a level II lymph node. A PA was defined as a lesion with a ratio of greater than 1.4 when compared to the level I and level II lymph node. This cutoff was determined based on the normalized ratios between level II and level I lymph nodes. Results of intraoperative parathyroid hormone assays and surgical pathology were used to validate the accuracy of this technique.

RESULTS

The sensitivity of this method in APNCT is 90.9% whereas positive predictive value is 100%. The sensitivity or positive predictive value of ultrasound and nuclear medicine are 60% or 100% and 90% or 100%, respectively.

CONCLUSION

The sensitivity of APNCT is equivalent to that of MPNCT in identifying PA.

Accuracy of 2-Phase Parathyroid CT for the Preoperative Localization of Parathyroid Adenomas in Primary Hyperparathyroidism

BACKGROUND AND PURPOSE

Minimally invasive parathyroidectomy requires accurate preoperative localization of suspected adenomas, and multiphase CT allows adenoma characterization while providing detailed anatomic information. The purpose of this study was to assess the feasibility of a protocol using only arterial and venous phases to localize pathologic glands in patients with primary hyperparathyroidism.

MATERIALS AND METHODS

We identified 278 patients with primary hyperparathyroidism who had undergone 2-phase CT with surgical cure. All scans were read prospectively by board-certified neuroradiologists. A neuroradiology fellow retrospectively reviewed images and reports and classified suspected adenomas on the basis of anatomic location. Accuracy was determined by comparing imaging results with surgical findings. The ability of 2-phase CT to localize adenomas to 1 of 4 neck quadrants and lateralize them to the correct side was assessed. Accuracy of identifying multigland disease was also evaluated.

RESULTS

In patients with single-gland disease, the sensitivity and specificity of 2-phase CT to correctly localize the quadrant were 55.4% and 85.9%, respectively. The sensitivity and specificity of correct lateralization were 78.8% and 67.8%, respectively. The sensitivity and specificity to identify multigland disease were 22.9% and 79.5%, respectively.

CONCLUSIONS

While the 2-phase CT protocol in this study demonstrates lower accuracy compared with reports of other techniques, its lower radiation compared with 3- and 4-phase techniques may make it a feasible alternative for preoperative parathyroid localization. Further prospective studies are needed to identify patients for whom this technique is most suitable.

MR appearance of parathyroid adenomas at 3 T in patients with primary hyperparathyroidism: what radiologists need to know for pre-operative localization

OBJECTIVES

To identify frequent MRI features of parathyroid adenomas (PTAs) in patients with primary hyperparathyroidism (PHPT) using a fast protocol with a 3 T magnet.

METHODS

Thirty-eight patients with PHPT underwent a 3 T-MR. All patients had positive US and Tc-99 sestamibi, for a total number of 46 PTAs. T2-weighted IDEAL-FSE and T1 IDEAL-sequences, before and after contrast, were performed. Five features of PTAs were recognised: hyperintensity, homogeneous or "marbled" appearance and elongated morphology on T2-sequences; cleavage plane from thyroid gland on T2-outphase; rapid enhancement in post-contrast T1. Image quality for T2-weighted IDEAL FSE and usefulness for IDEAL post-contrast T1-weighted and T2-outphase sequences were also graded.

RESULTS

PTAs were hyperintense in T2-sequences in 44/46 (95.7%), "marbled" in 30/46 (65.2%) and elongated in 38/46 (82.6%) patients. Cleavage plane was observed in 36/46 (78.3%), and rapid enhancement in 20/46 (43.5%) patients. T2-sequences showed both excellent fat suppression and image quality (average scores of 3.2 and 3.1). T2-outphase images demonstrated to be quite useful (score 2.8), whereas, post-contrast T1 images showed a lower degree of utility (score 2.4).

CONCLUSIONS

A fast protocol with 3.0-T MRI, recognising most common features of PTAs, may be used as a second-line method in the preoperative detection of PTAs.

KEY POINTS

3 T MRI protocol based on T2-weighted IDEAL FSE sequences was used. T2-hyperintensity and elongated morphology are common features of PTAs. 3 T MRI could be used in the preoperative detection of PTAs.

Parathyroid Adenomas and Hyperplasia on Four-dimensional CT Scans: Three Patterns of Enhancement Relative to the Thyroid Gland Justify a Three-Phase Protocol

PURPOSE

To describe the prevalence of three relative enhancement patterns of parathyroid lesions on four-dimensional (4D) computed tomographic (CT) scans.

MATERIALS AND METHODS

The institutional review board approved this HIPAA-compliant study and waived the need for informed consent. The authors retrospectively reviewed preoperative 4D CT scans obtained from November 2012 to June 2014 in 94 patients with pathologically proven parathyroid adenomas or hyperplasia. Lesions were classified into one of three relative enhancement patterns. All patterns required lesions to be lower in attenuation than the thyroid on non-contrast material-enhanced images, but patterns differed in the two contrast-enhanced phases. Type A lesions were higher in attenuation than the thyroid in the arterial phase, type B lesions were not higher in attenuation than the thyroid in the arterial phase but were lower in attenuation than the thyroid in the delayed phase, and type C lesions were neither higher in attenuation than the thyroid in the arterial phase nor lower in attenuation than the thyroid in the delayed phase. The prevalence of the relative enhancement patterns was compared. The t test was used to compare mean attenuation differences in Hounsfield units between the relative enhancement patterns.

RESULTS

Ninety-four patients had 110 parathyroid lesions, including 11 patients with multigland disease. The sensitivity for single-gland disease was 94% (78 of 83) and that for multigland disease was 59% (16 of 27). Type B enhancement was most common, with a prevalence of 57% (54 of 94), followed by type C (22% [21 of 94]) and type A (20% [19 of 94]). Five lesions were interpreted incorrectly as parathyroid adenoma (false-positive), and all lesions had the type C pattern. Relative to the thyroid, lesions categorized as type A by readers had mean attenuation difference (± standard deviation) of 39 HU ± 13 in the arterial phase, and type B lesions had a difference of -58 HU ± 26 in the delayed phase. These values differed from the mean attenuation difference of lesions not in these categories (P < .001).

CONCLUSION

Parathyroid adenomas and hyperplasia can be grouped into three relative enhancement patterns based on a protocol with a non-contrast-enhanced and two contrast-enhanced phases. The type B pattern is most common and could be diagnosed with two contrast-enhanced phases. However, almost one quarter of lesions have the type C pattern and thus could be missed without the non-contrast-enhanced phase.

How to perform parathyroid 4D CT: tips and traps for technique and interpretation

Parathyroid four-dimensional (4D) computed tomography (CT) is an imaging technique for preoperative localization of parathyroid adenomas that involves multidetector CT image acquisition during two or more contrast enhancement phases. Four-dimensional CT offers an alternative or additional tool in the evaluation of primary hyperparathyroidism. The purpose of this article is to describe the 4D CT technique and provide a practical guide to the radiologist for imaging interpretation. The article will discuss the rationale for imaging, approach to interpretation, imaging findings, and pitfalls.

Preoperative Localization of Parathyroid Adenomas Using 4-Dimensional Computed Tomography: A Pictorial Essay

Accurate preoperative localization is the key to successful parathyroid surgery in the era of minimally invasive parathyroid surgery. This article presents and discusses the embryologic basis of parathyroid gland and ectopic location and different imaging modalities helpful in diagnosing and localizing parathyroid adenomas and/or hyperplasia. We also aim to review the current surgical concepts in treatment of parathyroid adenomas and/or hyperplasia, the utility of 4-dimensional computed tomography for accurate preoperative localization of hyperfunctioning parathyroid glands, imaging classification of adenomas and/or hyperplasia, and, finally, present some of the limitations of 4-dimensional computed tomography.

The Utility of Multidetector Computed Tomography for Detection of Parathyroid Disease in the Setting of Primary Hyperparathyroidism

Purpose

The aim of this study was to evaluate the accuracy of multidetector computed tomography (MDCT) in the detection of parathyroid adenoma and hyperplasia in the setting of primary hyperparathyroidism.

Methods

Records of 48 patients with biochemically confirmed primary hyperparathyroidism, who underwent preoperative imaging with 16- or 64-slice contrast-enhanced MDCT and subsequent successful parathyroidectomy over a 3-year period, were reviewed. Two radiologists, blinded to the operative and histologic findings, independently evaluated multiplanar computed tomographic images for all patients.

Results

On pathologic examination, 63 abnormal glands were confirmed in 41 female and 7 male patients (mean age, 63 years). Of the 63 abnormal glands, 40 were adenomatous and 23 were hyperplastic. MDCT demonstrated an 88% (95% confidence interval [CI], 77%–99%) positive predictive value for localizing abnormal hyperfunctioning parathyroid glands. The sensitivity of MDCT in detecting single-gland disease was 80% (95% CI, 68%–92%); whereas the specificity for ruling out hyperfunctioning parathyroid tissue, either adenomatous or hyperplastic, was 75% (95% CI, 51%–99%). The sensitivity for exclusively localizing parathyroid hyperplasia was 17% (95% CI, 2%–33%). The parathyroid adenomas were substantially larger and heavier than their hyperplastic counterparts, with an average weight of 1.51 g (range, 0.08–6.00 g) and 0.42 g (range, 0.02–2.0 g) for adenoma and hyperplasia, respectively.

Conclusions

Contrast-enhanced MDCT demonstrated an 88% positive predictive value for localizing adenomatous and hyperplastic parathyroid glands. The poor sensitivity for detection of multigland disease was likely a result of the smaller size and weight of the abnormal hyperplastic glands.

Parathyroid lesions: characterization with dual-phase arterial and venous enhanced CT of the neck

This clinical report describes the enhancement characteristics of hypersecreting parathyroid lesions on dual-phase neck CT. We retrospectively analyzed the enhancement characteristics of 5 pathologically confirmed PTH-secreting lesions on dual-phase CT examinations. Attenuation values were measured for PTH-secreting lesions, vascular structures (CCA and IJV), and soft tissue structures (thyroid gland, jugulodigastric lymph node, and submandibular gland). From the attenuation values, "relative enhancement washout percentage" and "tissue-vascular ratio" were calculated and compared. All lesions decreased in attenuation from arterial to venous phase, while the mean attenuation values of other soft tissue structures increased. A high relative enhancement washout percentage was correlated with parathyroid lesions (P < .006). The tissue-CCA ratio and tissue-IJV ratio for PTH-secreting lesions in the arterial phase were statistically significantly higher compared with soft tissue structures (P < .05). If these results are validated in future larger studies, noncontrast and delayed venous phases of 4D-CT could be eliminated to markedly reduce radiation exposure.

Contribution of multimodality imaging for positive and aetiological diagnosis of multiple brown tumours

This report concerns a rare case of multiple brown tumours discovered in a setting of primary hyperparathyroidism in a 64-year-old patient presenting with weight loss and leg pain. Biological, radiological and pathological findings led to the diagnosis of brown tumours. The contribution of anatomic and nuclear imaging techniques to the diagnosis of brown tumours and their aetiological assessment as well as pre-surgery localisation of parathyroid adenomas in the context of primary hyperparathyroidism is discussed.

Bilateral neck exploration in primary hyperparathyroidism--when is it selected and how is it performed?

BACKGROUND

Although most patients with primary hyperparathyroidism (PHPT) are ideal candidates for minimally invasive parathyroidectomy, some will have more than one enlarged gland and require bilateral neck exploration to achieve biochemical cure. We evaluated the clinical evidence for when to choose bilateral neck exploration for patients with PHPT.

METHODS

We searched PubMed for English-language studies published from 1996 to 2008. The level of clinical evidence was determined according to the criteria proposed by Sackett (Chest 95[2 Suppl]:2S, 1989), and the grade of recommendation was established according to the criteria proposed by Heinrich et al. (Ann Surg 243:154, 2006).

RESULTS

Level III-IV evidence shows that patients with multiple endocrine neoplasia (MEN) 1 and PHPT should have a bilateral neck exploration (grade C recommendation). Only level IV evidence indicates that patients with familial PHPT should do so (no recommendation). Although most patients with MEN 2A have single-gland disease, bilateral neck exploration is still indicated, because they will have either a therapeutic or prophylactic total thyroidectomy for medullary thyroid cancer. A history of head and neck irradiation is associated with PHPT, but the risk of multi-gland parathyroid disease is apparently no higher than in sporadic cases (level IV evidence, no recommendation). Previous or current lithium therapy confers a higher risk of multi-gland disease (25%-45%; level IV-V evidence), which may require bilateral neck exploration. Preoperative localizing studies reliably identify most patients with single-gland but not multi-gland disease (level II-IV evidence). Negative localizing studies confer an approximately 50% risk of multi-gland disease and indicate that bilateral neck exploration is necessary. If two localizing studies are concordant, few patients will require bilateral neck exploration (level IV, no recommendation).

CONCLUSIONS

No level I or II evidence reliably identifies preoperative clinical risk factors for determining which patients should have routine bilateral neck exploration for multi-gland disease or for intraoperative decision making to convert to bilateral neck exploration. Imaging studies are positive in most patients (level II). No randomized studies exist to determine when a bilateral neck exploration is indicated based on clinical risk factors or imaging studies that may suggest multi-gland disease.

Focus on parathyroid carcinoma

Parathyroid carcinoma is a malignant neoplasm affecting 05-2 per cent of all patients with primary hyperparathyroidism that was first described by de Quevain in 1904. To day it continues to defy diagnosis and treatment. It is difficult to diagnose in part because of its rarity, lack of definitive diagnostic markers and overlapping clinical features of benign primary hyperparathyroidism. As a result initial surgical treatment is inadequate essentially leading to disease recurrence where complete cure is unlikely. En bloc surgical resection remains the only curative treatment, and high priorities are improving diagnostic methods, and clinical staging for resection once the disease is suspected. Margin status at resection is related to prognosis. Thus, a trend towards aggressive surgical management has improved outcomes. The recurrence rate of parathyroid carcinoma is as high as 80% with survival rates <50% at 10 years. Results of chemotherapy are disappointing. However, recent trials using radiation therapy are promising, but require further study.

Contrast-enhanced MDCT characteristics of parathyroid adenomas

OBJECTIVE

Minimally invasive directed parathyroidectomy has replaced conventional surgical techniques aimed at exploring all four glands in the bilateral neck. These changes have created the need for better preoperative imaging localization techniques. In this article, we describe the CT imaging characteristics of surgically confirmed adenomas and review anatomy and embryology to aid the radiologist in successfully identifying adenomas using contrast-enhanced CT.

CONCLUSION

Knowledge of normal CT appearance, contrast enhancement, and expected location are critical to correct interpretation of parathyroid adenoma at CT.

Assessment of parathyroid glands in hemodialysis patients by using color Doppler sonography

The aim of this study was to assess the role of color and spectral Doppler ultrasound (CDU) in the evaluation of enlarged parathyroid glands in hemodialysis patients with secondary hyperparathyroidism. Fourteen hemodialysis patients with elevated intact parathyroid hormone (iPTH) levels were evaluated prospectively with CDU. The volume of each observed parathyroid gland and the spectral CDU data (velocities, resistance and pulsatility indices, systolic to diastolic ratio, and flow volume output (FVO)) were noted. The biochemical data (iPTH, calcium, phosphate levels), and CDU results were analyzed with the Spearman correlation test. Two patients were excluded, and 27 enlarged parathyroid glands were observed in 12 patients. The mean total volume of enlarged parathyroid glands per patient was 1.95 cm(3) (0.06-5.5 cm(3)). Arterial supply was demonstrated in 78% (21/27) of enlarged parathyroid glands. Mean total FVO of enlarged glands per patient was 238.5 ml/min (620-0 ml/min) and mean iPTH level was 1,477 pg/ml (643-3,132 pg/ml). The positive correlations of total volume (p = 0.022), iPTH (p = 0.024), and FVO (p = 0.022) were statistically significant. In secondary hyperparathyroidism, total volume of the visualized enlarged parathyroid glands and the total of FVOs per patient are positively correlated with iPTH levels which may help clinical management and follow-up of end-stage renal disease patients.

Multidetector CT in diagnostic work-up of patients with primary hyperparathyroidism

PURPOSE

This study was performed to evaluate the accuracy of multidetector computed tomography (MDCT) in detecting parathyroid lesions in patients with primary hyperparathyroidism.

MATERIALS AND METHODS

We included 60 patients with primary hyperparathyroidism. Preoperative first-line examinations revealed negative and doubtful ultrasound (US) findings in 34 and 26 cases, respectively, and negative, doubtful and positive scintigraphic findings in 19, 20 and 21 cases, respectively. CT findings were compared with the surgical results.

RESULTS

CT examination was positive in 35 cases, negative in 15 cases and doubtful in ten cases. Forty out of 60 patients underwent surgery, and 39 lesions (37 adenomas, two primary hyperplasias) were identified. Surgery was negative in two cases. In eight cases, lesions had ectopic location. Surgery confirmed the CT findings in 23 positive cases. In 8/10 doubtful cases, surgery confirmed the location of the lesion in five cases, identified the ectopic location of lesions in two cases, and was negative in one case. In 9/15 cases with negative CT findings, surgery identified the lesion in eight cases. Sensitivity, specificity and diagnostic accuracy values were 78%, 25% and 73%, respectively.

CONCLUSIONS

MDCT is an accurate second-line diagnostic technique in the detection of parathyroid lesions, allowing exploration of the entire cervical and mediastinal regions.

Parathyroid imaging: technique and role in the preoperative evaluation of primary hyperparathyroidism

OBJECTIVE

This article discusses the commonly used techniques for imaging the parathyroid glands and their role in the preoperative evaluation of patients with primary hyperparathyroidism.

CONCLUSION

The importance of sonography and sestamibi scintigraphy in the preoperative evaluation of patients with primary hyperthyroidism has increased with the adoption of minimally invasive parathyroidectomy techniques at most medical centers. When the results of these studies are concordant, the cure rates of minimally invasive surgery equal those of traditional bilateral neck exploration.

Parathyroid sonography: imaging and intervention

This article reviews the role of high-resolution sonography as an imaging modality for the diagnosis and treatment of patients with parathyroid disease. Included is a discussion of sonographic anatomy and technique, disease processes of the parathyroid glands and their sonographic appearances, preoperative imaging, and the use of sonography as a guide for diagnostic and therapeutic intervention in parathyroid disease.

High resolution MRI in the detection of an intrathymic parathyroid adenoma

The most common cause of primary hyperparathyroidism is parathyroid adenoma. Of these, up to 20% have been reported to be in ectopic locations. Multiple imaging techniques have been utilized in the detection of ectopic adenoma and are discussed. We report on a case of an intrathymic parathyroid adenoma that was detected through the novel use of a breast coil in performing a high resolution MRI. The accurate localization permitted minimally invasive surgery, obviating morbidity associated with a sternotomy.

Optimizing preoperative imaging in primary hyperparathyroidism

BACKGROUND

Scintigraphy of the hyperfunctioning parathyroid glands using technetium 99m ((99m)Tc)-methoxyisobutylisonitrile ((99m)Tc-MIBI) is an established and highly sensitive preoperative localization tool whose importance has been further increased by advances in minimally invasive surgery . The goal of the present prospective study was to determine the benefit of optimized imaging in a consistent patient population.

METHODS

Eighty-four patients with first presentations of primary hyperparathyroidism were investigated with (99m)Tc-MIBI scintigraphy, thyroid scintigraphy, and cervical ultrasonography. The evaluation algorithm consisted of (a) evaluation of the planar images alone, (b) additional evaluation of single-photon emission computed tomography (SPECT), (c) additional evaluation of thyroid gland scintigraphy, and (d) additional evaluation of ultrasound. All patients subsequently underwent parathyroidectomy. The intraoperative and the histologic findings were correlated with the results of the scintigraphic imaging.

RESULTS

The sensitivity of planar parathyroid scintigraphy was 74% and could be increased to 91% by the additional investigations. The difference was statistically significant (p<0.05). At the same time, a small increase in specificity from 96% to 99% was seen.

CONCLUSIONS

Prior to minimally invasive treatment of hyperparathyroidism, we recommend combined localization studies consisting of sequential (99m)Tc-MIBI scintigraphy, additional SPECT plus thyroid gland scintigraphy, plus high-resolution cervical ultrasonography.

Two Hundred Consecutive Parathyroid Ultrasound Studies by a Single Clinician: The Impact of Experience

OBJECTIVE

To assess the ability of ultrasound studies, performed by an experienced clinician, to predict surgical findings and provide precise anatomic localization of abnormal parathyroid glands.

METHODS

We retrospectively examined 200 consecutive parathyroid ultrasound studies performed by a single experienced clinician in our unit. All patients subsequently underwent parathyroidectomy, with histopathologic confirmation of abnormal parathyroid tissue. The correlation between the ultrasound and surgical findings was assessed.

RESULTS

Of the 200 study patients, 197 (98.5%) were cured of their disease at the initial operation. Ultrasound studies correctly predicted the surgical findings in 88% of patients, including 168 of 180 (93%) with single gland disease and 7 of 20 (35%) with multiple gland disease (MGD). In all cases in which a single adenoma was identified, precise information regarding its location relative to adjacent anatomic structures was provided. In 92% of these cases, anatomic details correlated closely with surgical findings. Ectopic and descended superior adenomas were most frequently missed. Patients with two nonlocalizing studies (scintigraphy and ultrasonography) had a >50% likelihood of having MGD.

CONCLUSION

In experienced hands, parathyroid ultrasonography is a highly sensitive technique that provides both localization of enlarged parathyroid glands and precise anatomic detail. Thus, in this study, focused parathyroidectomy was possible in 76.5% of patients. MGD remains difficult to diagnose preoperatively. Nonlocalizing studies should alert the surgeon to a high probability of MGD and prompt the performance of 4-gland exploration.

Technetium-99m-MIBI SPECT/CT in Primary Hyperparathyroidism

The novel trend toward focused parathyroidectomy requires precise preoperative localization of the parathyroid adenoma in patients with primary hyperparathyroidism (PHPT). The present study evaluated the impact of hybrid single photon emission computed tomography/computed tomography (SPECT/CT), using 99mTc-sestamibi (MIBI), on the surgical management of these patients. In a retrospective study of 36 patients with PHPT, SPECT/CT was undertaken when planar 99mTc-MIBI scintigraphy was negative or when an ill-defined focus in the neck or an ectopic site on planar views was visualized. Imaging data were compared with intraoperative findings, and the incremental value of SPECT/CT to lesion localization and surgical procedure was assessed. Three patients with both negative planar and SPECT/CT studies subsequently underwent bilateral neck exploration, with multiglandular hyperplasia diagnosed in two patients and a parathyroid adenoma in one. Of 33 patients with a positive MIBI study, parathyroid adenoma was confined to the neck in 23 patients and to the lower neck-mediastinum in 10. SPECT/CT facilitated the surgical exploration of all 10 ectopic parathyroid adenomas and 4 of 23 cervical parathyroid adenomas, the latter four either at reexploration or in patients with nonvisualization of the thyroid after thyroidectomy. SPECT/CT contributed to the localization of parathyroid adenomas in patients with PHPT and to planning the surgical exploration in 14 of 36 (39%) patients, predominantly those with ectopic parathyroid adenomas or who had distorted neck anatomy.

Minimally invasive procedure for resection of a parathyroid adenoma: the role of preoperative high-resolution ultrasonography

PURPOSE

Solitary adenoma of the parathyroid is the major cause of primary hyperparathyroidism. Many centers advocate a minimally invasive surgical approach, wherein the surgeon explores only a localized area of the neck according to the preoperative imaging evaluation, and the adenoma is resected without histological sampling from the other parathyroid glands. The aim of this study was to evaluate the ability of high-resolution ultrasonography (US) to localize adenomas preoperatively and thereby aid in patient selection for minimal procedures.

METHODS

We reviewed the medical records of 77 consecutive patients who underwent resection of a parathyroid adenoma following ultrasonographic imaging between 2001 and 2002, and we assessed the accuracy of the preoperative localization of the adenomas as well as the efficacy of the minimally invasive procedure.

RESULTS

US correctly localized the adenoma to a specific quadrant of the neck in 87% of the cases and to a specific side of the neck in 94%. Overall, US sensitivity was 89%, with a positive predictive value of 98%. Its sensitivity was not reduced by the presence of nodular disease of the thyroid gland. Success rate for the minimal procedure was 98% (50/51 patients).

CONCLUSIONS

US performed by a skilled operator is a reliable tool for adenoma localization prior to minimally invasive parathyroidectomy. If the US findings are inconclusive, a Tc-sestamibi scan should be used. If there is a high clinical suspicion of adenoma in the presence of negative imaging studies, bilateral neck exploration should be performed.

A systematic review of the diagnosis and treatment of primary hyperparathyroidism from 1995 to 2003

OBJECTIVE

To systematically review the current preoperative diagnostic modalities, surgical treatments, and glandular pathologies associated with primary hyperparathyroidism.

STUDY DESIGN

A systematic literature review.

RESULTS

Of the 20,225 cases of primary hyperparathyroidism reported, solitary adenomas (SA), multiple gland hyperplasia disease (MGHD), double adenomas (DA), and parathyroid carcinomas (CAR) occurred in 88.90%, 5.74%, 4.14%, and 0.74% of cases respectively. Tc 99m -sestamibi and ultrasound were 88.44% and 78.55% sensitive, respectively, for SA, 44.46% and 34.86% for MGHD, and 29.95% and 16.20% for DA, respectively. Postoperative normocalcemia was achieved in 96.66%, 95.25%, and 97.69% of patients offered minimally invasive radio-guided parathyroidectomy (MIRP), unilateral, and bilateral neck exploration (BNE). Intraoperative PTH assays (IOPTH) were helpful in approximately 60% of bilateral neck exploration conversion (BNEC) surgeries.

CONCLUSION

The overall prevalence of multiple gland disease (MGD and DA) was lower than often suggested by conventional wisdom. Furthermore, preoperative imaging was less accurate than it is often perceived for accurately imaging MGD. MIRP and UNE were more successful in achieving normocalcemia than is typically quoted. IOPTH was a helpful but not "fool-proof" adjunct in parathyroid exploration surgery.

SIGNIFICANCE

These results support a greater role for the treatment of primary hyperparathyroidism using less invasive approaches. EMB rating: B-3.

Diagnosis and Management of Multiple Endocrine Neoplasia Type 1 (MEN1)

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominantly inherited disorder, characterised by the occurrence of tumours of the parathyroid glands, the pancreatic islets, the pituitary gland, the adrenal glands and neuroendocrine carcinoid tumours. Carcinoid tumours of the thymus and pancreatic-duodenal gastrinomas are the most harmful tumour types, since these tumours have malignant potential and curative treatment is difficult to achieve.MEN1 is caused by germline mutations of the MEN1 tumour suppressor gene. Mutation analysis enables mutation carriers to be identified. MEN1 patients and their family members, family members of mutation carriers and patients who are clinically suspected to be carriers of a MEN1 gene mutation are eligible for mutation analysis. MEN1-associated tumours can be detected and treated at an early stage through periodical clinical monitoring of mutation carriers.

The cost-effectiveness of sestamibi scanning compared to bilateral neck exploration for the treatment of primary hyperparathyroidism

This article presents a cost-effectiveness analysis to determine whether preoperative imaging with Tc99m-sestamibi for detection and treatment of solitary adenomas associated with primary hyperparathyroidism is cost-effective compared with routine bilateral neck exploration.

Challenges In Neck Ultrasonography: Lymphadenopathy And Parathyroid Glands

OBJECTIVE

To assess the performance of neck ultrasonography (US) in the detection of lymph node lesions metastatic from differentiated thyroid carcinoma (DTC) and the detection of parathyroid adenomas.

METHODS

Neck US was performed in 667 patients with DTC (173 men and 494 women; mean age, 47.7 years). In cases of suspicious neck nodes, US-guided fine-needle aspiration biopsy (US-FNAB) plus measurement of thyroglobulin in the needle washouts (FNAB-Tg) was done. In addition, 75 patients with primary hyperparathyroidism (pHPT) (15 men and 60 women; mean age, 56 years) underwent neck US and sestamibi scintiscanning for localization of parathyroid adenoma. For confirmation of US findings, US-FNAB plus measurement of parathyroid hormone in the needle washouts (FNAB-PTH) was performed. FNAB-PTH was also measured in 129 suspected parathyroid adenomas incidentally detected in a series of 4,129 patients undergoing neck US examination for thyroid disease.

RESULTS

The presence of DTC metastatic lesions was confirmed in 46 of 95 patients with suspicious neck nodes. US sensitivity and specificity were 82.1% and 91.2%, respectively. The positive predictive value (PPV) of US-FNAB + FNAB-Tg was 94.7%. In the 75 patients with pHPT, US followed by US-FNAB + FNAB-PTH showed a higher PPV (97.5%) in comparison with sestamibi scintiscanning (83.7%) in the detection of parathyroid adenoma. A parathyroid adenoma was also incidentally detected in 0.62% of the 4,129 patients undergoing neck US for thyroid disease.

CONCLUSION

US accurately detects DTC neck metastatic lesions and localizes parathyroid adenomas. Moreover, neck US may lead to discovery of parathyroid incidentalomas.

The diagnostic utility of computed tomography for preoperative localization in surgery for hyperparathyroidism

OBJECTIVES/HYPOTHESIS

Successful unilateral or minimal-access parathyroid exploration and reoperative surgery of the parathyroid glands requires accurate preoperative localization of parathyroid disease. Although ultrasound and nuclear imaging techniques have an established role in this regard, the use of computed tomography (CT) for parathyroid exploration is not well understood. The purpose of the present study was to better define the diagnostic utility of CT in preoperative localization of the abnormal gland in surgery for hyperparathyroidism.

STUDY DESIGN

Retrospective cohort study.

METHODS

All parathyroid explorations performed at Oregon Health and Science University (Portland, OR) between 2000 and 2002 were reviewed. The study group was limited to patients with hyperparathyroidism in whom localization failed preoperatively using ultrasound and/or sestamibi scanning and subsequent investigation using CT imaging was performed. Operative, pathological, and imaging reports were then analyzed to assess the accuracy of CT imaging for localizing parathyroid disease.

RESULTS

Twenty-two patients with hyperparathyroidism were investigated preoperatively using CT imaging. Parathyroid exploration was successful in all but one patient, leaving 21 patients in all in the cohort. The majority of cases (67%) were reoperative, and all patients had previously undergone inconclusive ultrasound and/or sestamibi scanning. Computed tomography correctly localized parathyroid disease in 18 (86%) of the 21 patients who underwent successful extirpation of parathyroid disease and was able to identify abnormal glands with equal utility in the neck and the chest.

CONCLUSION

When ultrasound or sestamibi are unsuccessful, CT imaging can provide valuable preoperative localizing information before surgery for hyperparathyroidism, particularly in patients with recurrent or persistent disease.

Technetium-99m sestamibi scintigraphy and helical CT together in patients with primary hyperparathyroidism: a prospective clinical study

44 consecutive patients with confirmed primary hyperparathyroidism (HPT) undergoing surgery were prospectively enrolled in the study. There were 13 (29.5%) men and 31 (70.5%) women with an overall median age of 59 years (range 23-78 years). Prior to successful parathyroidectomy both (99)Tc(m)-sestamibi/(99)Tc(m)-pertechnetate subtraction scintigraphy (SS) and helical CT were performed, and the results of imaging studies were compared against intraoperative findings. Final histopathology showed 40 (90.9%) solitary parathyroid (PT) adenomata (median size 18 mm, range 8-40 mm), that were in an ectopic location in 13 (32.5%) patients. Moreover, 3 (6.8%) patients had multiglandular disease (one patient with two PT adenomata, two patients with PT hyperplasia), while one (2.3%) patient had a PT carcinoma. The sensitivity and positive predictive value were 86.0% and 97.4% for SS, 88.1% and 94.9% for CT, and 100% and 97.4% for the combination of SS and CT, respectively. Calcium and parathyroid hormone (PTH) serum levels, and the mean size of the removed PT glands of patients with false negative results were lower than that of those with true positive results, but the difference was not significant. Among patients with solitary PT tumours (N=41) the sensitivity was 88.1% and 90.3% for SS and CT-scan, respectively. In conclusion, our study confirms the usefulness of SS, which should be the initial test for patients undergoing parathyroidectomy. However, the strategy of performing two tests in each patient with primary HPT could be of limited utility when the initial SS is positive.

Primary hyperparathyroidism in pregnancy: evidence-based management

Primary hyperparathyroidism during pregnancy poses significant risks to the mother and the fetus. Fortunately, prompt diagnosis and effective management can improve outcomes for both. There is controversy regarding appropriate management of these patients, especially late in gestation. The objective of this article, therefore, is to review the literature and to propose an evidence-based approach to managing these patients. The prevalence of primary hyperparathyroidism in the general population is 0.15%. This condition is more common in women and 25% of cases appear in women during the childbearing years. The true incidence during pregnancy, however, is not known. Because up to 80% of gravid patients with primary hyperparathyroidism are asymptomatic, diagnosing this condition is more difficult. Complications associated with primary hyperparathyroidism in pregnancy have been reported to occur in up to 67% of mothers and 80% of fetuses. In addition to many constitutional symptoms, maternal complications include nephrolithiasis, bone disease, pancreatitis, hyperemesis, muscle weakness, mental status changes, and hypercalcemic crisis. Reported fetal complications include intrauterine growth retardation, low birth weight, preterm delivery, intrauterine fetal demise, postpartum neonatal tetany, and permanent hypoparathyroidism. A four-fold decrease in perinatal complications may be achieved with appropriate therapy. Conservative intervention may be appropriate under certain circumstances, but excision of a parathyroid adenoma remains the only definitive treatment. Debate continues regarding the safety of surgery in the third trimester. However, several cases of successful surgery have been reported.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will be able to describe the typical presentation of a patient with hyperparathyroidism, summarize the work up and management of a patient with hyperparathyroidism, and list the treatment options for a pregnant patient with hyperparathyroidism.