Ultrasonography: highly accuracy technique for preoperative localization of parathyroid adenoma

4DCT in Discordant Parathyroid Adenoma Scans: Case Series and Meta-Analysis

OBJECTIVE

To evaluate the accuracy of four-dimensional computerized-tomography (4DCT) for localizing parathyroid adenomas (PTAs) in cases with discordant or non-localizing ultrasonography (US) and Technetium-99 sestamibi (MIBI) scans.

DATA SOURCES

Retrospective case series and systematic review.

REVIEW METHODS

A case series and meta-analysis of patients diagnosed with primary hyperparathyroidism and discordant US and MIBI scans who underwent 4DCT prior to surgery. A comprehensive search for all relevant publications in the English literature between December 2006 and March 2022 was conducted for the meta-analysis. Patients undergoing parathyroidectomy between January 2015 and December 2021 were identified from the institutional electronic database for the case series. All studies were analyzed for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 4DCT adenoma localization capabilities.

RESULTS

Thirteen retrospective studies that included 379 patients and one case series that included 37 patients were identified and analyzed. A per-patient analysis revealed sensitivity for lateralization to the correct side (n = 181) ranging from 80% to 100% with a fixed effects model of 89% (95%confidence interval [CI]: 82%-93%) and a PPV for lateralization ranging from 63%-95% with a random effects model of 87% (95% CI: 77%-95%). Sensitivity of localization to the correct quadrant (n = 172) ranged from 53% to 100% with a random effects model of 90.4% (95% CI: 76%-99%), and the PPV for localization ranged from 52% to 100% with a random effects model of 82% (95% CI: 73%-89%).

CONCLUSION

4DCT enhances imaging capabilities of localizing PTAs in cases of discordant or non-localizing US and MIBI scans.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2198-2205, 2024.

Parathyroid carcinoma: Three case reports

BACKGROUND

Parathyroid carcinoma (PC) is a rare, slow-growing malignant tumor and a rare cause of primary hyperfunctioning of the parathyroid, with a highly variable clinical course, depending on the aggressiveness of the individual tumor and the degree of hypercalcemia.

CASE SUMMARY

The aim of this report is to summarize the diagnosis and treatment of three cases of PC and to review and conclude aspects regarding the three collected cases with reference to other relevant cases to explore the value of ultrasound in the diagnosis of PC. All three patients had hypercalcemia, consisting of a high serum calcium level and a high level of parathyroid hormone that was > 2-fold (even > 30-fold) of the normal upper limit. The ultrasonographic findings of the parathyroid gland showed that the glands were all > 30 mm, and the internal echo was uneven. All patients underwent surgery. PC in three cases was confirmed by routine histopathology and immunohistochemistry.

CONCLUSION

As clinical signs and laboratory results are nonspecific, it is difficult to diagnose PC preoperatively, so imaging examinations are often needed.

Parathyroid Cancer: A Review

Parathyroid cancer is one of the rarest causes of primary hyperparathyroidism and tends to present with more severe symptoms than its more benign counterparts. This article details various aspects of the disease process, including epidemiology, clinical presentation, and a step-wise diagnostic process for parathyroid cancer. This includes laboratory assessments as well as a proposed staging system. The en bloc principle of surgical intervention is detailed, as well as the current role of adjuvant treatments. A general guide to surveillance and the natural history of the disease is also outlined.

Parathyroid Cancer: A Review

Parathyroid cancer is one of the rarest causes of primary hyperparathyroidism and tends to present with more severe symptoms than its more benign counterparts. This article details various aspects of the disease process, including epidemiology, clinical presentation, and a step-wise diagnostic process for parathyroid cancer. This includes laboratory assessments as well as a proposed staging system. The en bloc principle of surgical intervention is detailed, as well as the current role of adjuvant treatments. A general guide to surveillance and the natural history of the disease is also outlined.

Actual role of color-doppler high-resolution neck ultrasonography in primary hyperparathyroidism: a clinical review and an observational study with a comparison of 99mTc-sestamibi parathyroid scintigraphy

PURPOSE

Primary hyperparathyroidism (PHPT) is a frequent endocrine pathology that has surgical treatment as its only decisive measure. High-Resolution Neck Ultrasonography with color-Doppler (CDHR-NUS) and 99mTechnetium-SestaMIBI Parathyroid Scintigraphy (99mTc-MIBI PS) are the two instrumental exams more commonly used in the preoperatory localization of pathologic parathyroids. The aim of this observational study was to outline-in accordance with the latest scientific literature-the precise role of CDHR-NUS in the environment of PHPT, comparing it with that of Parathyroid Scintigraphy.

METHODS

136 patients operated on for PHPT and underwent CDHR-NUS and 99mTc-MIBI PS preoperatively. The CDHR-NUS was carried out by an expert medical sonographer. The results of the two methods were compared between each other and with the results of the operative act for the evaluation of accordance and diagnostic performances.

RESULTS

PHPT is prevalently due to monoglandular pathology (SGD). The parallel use of CDHR-NUS and of 99mTc-MIBI PS does not determine a significant increase in diagnostic accuracy. The preoperative accordance evaluation between the two methods does not exclude the presence of multiglandular pathology (MGD) with certainty.

CONCLUSIONS

CDHR-NUS is an accurate as well as cost-effective method; its role as a main and eventual unique preoperative localization method in patients affected by PHPT is confirmed. In the presence of expert medical sonographers, the sequential use of the two methods is retained correct and their use in parallel is neither justified nor cost-effective. The preoperative accordance evaluation between the two methods is neither necessary nor indispensable.

In-Office Ultrasonographic Evaluation of Neck Masses/Thyroid Nodules

Office-based ultrasonography is increasingly becoming an integral part of an otolaryngology-head and neck surgery practice. A thorough knowledge of the ultrasonic appearance of normal and abnormal pathology are key for performing/interpreting office-based head and neck ultrasonography. A focused but systematic approach allows for efficient and effective office-based head and neck ultrasonography. Office-based ultrasonography also allows for imaging procedures expanding the otolaryngologist's armamentarium. Ultrasound-guided fine needle aspiration (USgFNA) is an integral part of clinician-performed ultrasonography because it allows cytologic diagnosis of suspicious lesions. Understanding the successful techniques and pitfalls in this procedure are critical for the otolaryngologist performing USgFNA.

Phantom Nodules Detected by Ultrasound Examination of the Neck: The Possibility of Ectopic Cervical Thymic Tissue in Adults

Purpose

The aim of this study was to investigate the ultrasound characteristics and clinical significance of slightly hyperechoic lesions, referred to as phantom nodules, in the perithyroidal area in patients.

Materials and Methods

A total of 128 patients who underwent thyroidectomy with central neck lymph node dissection at Kuma Hospital in Hyogo, Japan were included in the study. We detected 16 phantom nodules during preoperative ultrasound examinations, defined as slightly hyperechoic masses located in the perithyroidal areas, in 13 of these 128 patients (10.2%; mean age: 55.6 years, range: 36–75 years).

Results

All phantom nodules were located in the caudal region of the thyroid gland, and the mean maximum dimension was 7.2 mm. 12 of the 16 nodules were round or oval, while the remaining 4 were fusiform and molded by the surrounding tissue. All nodules were well-defined, solid, homogeneous, hyperechoic masses. No speckled echo pattern, internal linear echo, or vascular flow signal was observed. All 4 nodules subjected to histological examination were composed of ectopic thymic tissue. In 2 of these 4, the parenchyma was severely involuted and almost entirely replaced by adipose tissue.

Conclusion

To the best of our knowledge, this is the first report wherein some of the detected hyperechoic perithyroidal masses were composed of ectopic thymic tissue, and some were primarily composed of adipose tissue that completely replaced involuted ectopic thymic tissue. The results of the study suggest that these so-called phantom nodules are clinically insignificant and do not require fine needle aspiration cytology or further investigation.

Challenging pre-surgical localization of hyperfunctioning parathyroid glands in primary hyperparathyroidism: the added value of 18F-Fluorocholine PET/CT

PURPOSE

To evaluate the added value of ¹⁸F-Fluorocholine (¹⁸F-FCH) PET/CT in presurgical imaging of patients with primary hyperparathyroidism (HPT) and challenging localization of the hyper-functioning parathyroid glands.

METHODS

We included 27 consecutive patients with primary HPT (19 F; median age: 58 years), with either (i) non-conclusive pre-surgical localization with ⁹⁹mTc-sestaMIBI scintigraphy and neck ultrasonography (US), (ii) recurrence of previously operated HPT, or (iii) familiar HPT with a suspicion of multiple gland disease. Histological findings and resolution of HPT were considered as the gold standard.

RESULTS

¹⁸F-FCH PET/CT was positive in 24/27 patients. Twenty-one patients underwent surgery with 27 resected lesions (14 adenomas, 11 hyperplastic glands, two hyper-functioning histologically normal glands), with resolution of HPT in 19/21 patients (90%). ¹⁸F-FCH PET/CT localized 22 lesions in 17/21 patients (per patient: sensitivity 81%, positive predictive value (PPV) 94%; per gland: sensitivity 76%, PPV 85%, specificity 91%, negative predictive value (NPV) 86%). ¹⁸F-FCH PET/CT found eight lesions which were undetectable on both ⁹⁹mTc-sestaMIBI scintigraphy and US. In patients with a familial HPT and/or a multiple gland disease, sensitivity was 100 and 79% on a per-patient and a per-gland analysis respectively, while NPV was 63%. In six patients with a persistence or recurrence of previously treated HPT, ¹⁸F-FCH PET/CT localized all lesions, both in sporadic and familiar disease.

CONCLUSIONS

¹⁸F-FCH PET/CT is a promising modality in challenging pre-surgical localization of hyper-functioning parathyroid glands, such as inconclusive standard imaging, recurrence after surgery, or suspected multiple gland disease.

Can ARFI elastography be used to differentiate parathyroid from thyroid lesions?

OBJECTIVES

To assess if elasticity score (ES) and shear wave velocity (SWV) measurement obtained using ARFI elastography can differentiate between parathyroid lesions and thyroid nodules.

MATERIALS AND METHODS

ARFI elastography was performed on patients with primary hyperparathyroidism or solid thyroid nodules who were being considered for surgery using virtual touch quantification and virtual touch imaging (VTI) software. Only patients with surgical histopathology (47 parathyroid lesions, 38 benign thyroid nodules and 55 malignant thyroid nodules) were included for final analysis. SWV and ES of the parathyroid and thyroid nodules were compared and their ability to differentiate between parathyroid and thyroid was analyzed using receiver operating characteristic curve analysis.

RESULTS

There were 39 solitary adenomas, 2 double adenomas and 4 parathyroid hyperplasias with mean size of 19.6 ± 9.7 mm in 44 patients (21 male, 23 females) with primary hyperparathyroidism. The mean SWV of the parathyroid lesion (1.6 ± 0.78 m/s) was significantly different from benign (2.11 ± 0.8 m/s) and malignant (4.3 ± 2.71 m/s) thyroid nodules, p < 0.05; so was the ES, Chi square = 51.6, p < 0.001. The majority of parathyroid lesions (n = 37, 78.7%) had ES of 2 with speckled (n = 42, 89.3%) appearance, and none showed ES of 4. The diagnostic performance of speckled appearance on VTI, elasticity score and SWV measurements was 0.901, 0.724 and 0.797, respectively, to differentiate between parathyroid and thyroid lesions.

CONCLUSIONS

Parathyroid lesions are softer than thyroid nodules. A shear wave velocity of 1.72 m/s can differentiate between parathyroid lesions and thyroid nodules.

ULTRASOUND-GUIDED PERCUTANEOUS ETHANOL INJECTION THERAPY IN A 92 YEAR-OLD PATIENT WITH PARATHYROID ADENOMA AND WITH A HISTORY OF TOTAL THYROIDECTOMY FOR PAPILLARY THYROID CARCINOMA

Percutaneous Ethanol Injection Therapy (PEIT) of parathyroid adenoma under ultrasound guidance is individually used as an alternative procedure in management of primary hyperparathyroidism in polymorbid elderly patients with increased surgical risk. The treatment is also suitable for patients who already underwent surgery of the thyroid gland, and any other surgery is associated with a higher risk of postsurgical complications. We present a case of a 92-year-old male patient, who underwent thyroidectomy for papillary thyroid carcinoma three years ago. Part of the regular annual follow-up visits was also ultrasonography, which showed a solitary parathyroid adenoma at the site of the removed thyroid gland. Given the underlying condition, polymorbidity and age of the patient, the PEIT method was successfully used in the therapy. The coincidence of adenoma and papillary thyroid carcinoma is also interesting.

Errors and mistakes in ultrasound diagnostics of the thyroid gland

Ultrasound examination of the thyroid gland permits to evaluate its size, echogenicity, margins, and stroma. An abnormal ultrasound image of the thyroid, accompanied by other diagnostic investigations, facilitates therapeutic decision-making. The ultrasound image of a normal thyroid gland does not change substantially with patient's age. Nevertheless, erroneous impressions in thyroid imaging reports are sometimes encountered. These are due to diagnostic pitfalls which cannot be prevented by either the continuing development of the imaging equipment, or the growing experience and skill of the practitioners. Our article discusses the most common mistakes encountered in US diagnostics of the thyroid, the elimination of which should improve the quality of both the ultrasound examination itself and its interpretation. We have outlined errors resulting from a faulty examination technique, the similarity of the neighboring anatomical structures, and anomalies present in the proximity of the thyroid gland. We have also pointed out the reasons for inaccurate assessment of a thyroid lesion image, such as having no access to clinical data or not taking them into account, as well as faulty qualification for a fine needle aspiration biopsy. We have presented guidelines aimed at limiting the number of misdiagnoses in thyroid diseases, and provided sonograms exemplifying diagnostic mistakes.

Four ultrasound and clinical pictures of parathyroid carcinoma

Parathyroid carcinoma is a rare cause of primary hyperparathyroidism. It may be suspected based on severe clinical signs, significant laboratory findings, and the tumor size. High-resolution ultrasonography with Doppler imaging has become the principal imaging method in the preoperative diagnosis of primary hyperparathyroidism. The ultrasound finding is not specific, but three of the described pictures are different from the typical appearance of benign adenoma of the thyroid gland and were suspicious in the context of clinical findings. According to the ultrasound criteria, one finding was benign and only the histological examination revealed carcinoma.

The impact of surgeon-based ultrasonography for parathyroid disease on a British endocrine surgical practice

INTRODUCTION

Surgeon-based ultrasonography (SUS) for parathyroid disease has not been widely adopted by British endocrine surgeons despite reports worldwide of accuracy in parathyroid localisation equivalent or superior to radiology-based ultrasonography (RUS). The aim of this study was to determine whether SUS might benefit parathyroid surgical practice in a British endocrine unit.

METHODS

Following an audit to establish the accuracy of RUS and technetium sestamibi (MIBI) in 54 patients, the accuracy of parathyroid localisation by SUS and RUS was compared prospectively with operative findings in 65 patients undergoing surgery for primary hyperparathyroidism (pHPT).

RESULTS

The sensitivity of RUS (40%) was below and MIBI (57%) was within the range of published results in the audit phase. The sensitivity (64%), negative predictive value (86%) and accuracy (86%) of SUS were significantly greater than RUS (37%, 77% and 78% respectively). SUS significantly increased the concordance of parathyroid localisation with MIBI (58% versus 32% with RUS).

CONCLUSIONS

SUS improves parathyroid localisation in a British endocrine surgical practice. It is a useful adjunct to parathyroid practice, particularly in centres without a dedicated parathyroid radiologist, and enables more patients with pHPT to benefit from minimally invasive surgery.

Techniques for parathyroid localization with ultrasound

Four-gland parathyroid exploration has been the gold standard for parathyroid surgery until recently. Emphasis is now placed on minimally invasive and focused parathyroidectomy. In conjunction with functional sestamibi scanning, ultrasonography permits accurate localization of enlarged parathyroid glands in the vast majority of patients with hyperparathyroidism. Consequently, ultrasound technology applied to parathyroid pathology facilitates directed surgical therapy and minimally invasive applications. As such, ultrasonography holds great promise as a tool that enables cost-effective and advanced patient care.

Prevalence of parathyroid cysts by neck ultrasound scan in unselected patients

BACKGROUND

Parathyroid cysts (PC) are a rare entity, representing only 0.5-1% of all parathyroid lesions and <1% of neck masses. Since its first description, in the second half of the 19th century, fewer than 300 cases have been reported. By reviewing the literature, it appears that the data available arose from surgical series, and the precise incidence of PC as detected by ultrasound (US) has not been described. The aim of this study was to review 5 yr of routine neck US, mainly performed for thyroid diseases, in order to estimate the prevalence of PC in a large series of patients.

METHODS

We reviewed our database of neck US investigations performed from 2003 to 2007: all data regarding patient's clinical history, US images, and fine needle aspiration cytology were retrospectively collected.

RESULTS

Among 6621 patients submitted to neck US investigation, a PC (mean diameter 36.4+/-14.2 mm; range 25-61 mm) was diagnosed in 5 cases. Serum PTH levels were high in all the patients (221+/-140.7 pg/ml; range 111-456 pg/ml), whereas serum calcium levels only in 3 subjects (10.8+/-1.4 mg/dl; range 9.2-12.9 mg/ml).

CONCLUSION

This is the first study evaluating the prevalence of PC in a large series of unselected patients by US. Our results demonstrate a much lower incidence (0.075%) of incidentally detected PC than previously reported.