Ultrasonographic features of intrathyroidal parathyroid adenoma causing primary hyperparathyroidism

Enhancing point-of-care ultrasound (POCUS) utilization in primary care: A thyroid POCUS training course for internal medicine residents

BACKGROUND

POCUS is valuable in primary care, yet outpatient-specific point-of-care ultrasound (POCUS) curriculum integration into internal medicine (IM) residency is limited. We addressed this gap by developing a thyroid POCUS workshop for IM residents.

AIM

Develop and implement an educational curriculum to integrate thyroid POCUS into an IM residency program and evaluate the impact on resident knowledge, perceived skills, and attitudes.

SETTING

The study was conducted in a resident primary care clinic at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell Residency Program in Internal Medicine at North Shore University Hospital and Long Island Jewish Medical Center.

PARTICIPANTS

All 108 IM residents (PGY1-3) in one program participated in the study during their ambulatory clinic block.

PROGRAM DESCRIPTION

Residents participated in a 1-hour workshop involving a didactic session and two breakout groups: one for hands-on practice and another for case-based discussions with image review.

PROGRAM EVALUATION

Residents completed pre- and post-session surveys assessing knowledge, perceived skills, and attitudes toward thyroid POCUS. These data showed statistically significant increases in all assessed areas.

DISCUSSION

Integrating thyroid POCUS into an IM residency curriculum significantly improved resident knowledge, attitudes, and perceived skills related to these exams. Residents valued this learning experience and expressed intentions to incorporate it into their future practice.

The value of ultrasound in combination with 99mTc-MIBI imaging department of ultrasound medicine, for the diagnosis of ectopic parathyroid glands in the thyroid gland in patients with secondary hyperparathyroidism

To investigate the value of preoperative ultrasound combined with 99mTc-MIBI imaging for the diagnosis of ectopic intrathyroid parathyroid gland (ETPG) in patients with secondary hyperparathyroidism (SHPT). One hundred and eleven patients with SHPT who underwent total parathyroidectomy plus forearm transplantation from January 2015 to January 2022 in the Third Hospital of Hebei Medical University were selected. All patients underwent routine preoperative ultrasonography and 99mTc-MIBI imaging, and with pathological diagnosis as the gold standard, the clinical data of ETPG patients were selected, including clinical manifestations, laboratory tests, preoperative ultrasonography and 99mTc-MIBI imaging for localization and diagnosis, intraoperative exploration and postoperative pathology, and postoperative follow-up. To analyze the ultrasound manifestations of preoperative parathyroid hyperplasia and the results of 99mTc-MIBI imaging in patients with ETPG. Among 111 patients with SHPT, there were 5 patients with ETPG, 1 male and 4 females with a mean age of (45.00 ± 5.05) years, and 6 ectopic parathyroid glands were located in the thyroid gland. The incidence of ETPG was 4.5% (5/111), 4 were detected by ultrasound, 2 were not detected with a diagnostic accuracy of 66.7% (4/6), 3 were positive for 99mTc-MIBI imaging, 3 were negative with a diagnostic accuracy of 50.0% (3/6). Among them, one was not detected by ultrasound, but was positive for 99mTc-MIBI imaging, 2 with negative 99mTc-MIBI imaging, but all were detected by ultrasound, and one with negative 99mTc-MIBI imaging was detected by ultrasound but misdiagnosed as a thyroid nodule. A total of 5 ETPGs were detected by ultrasound combined with 99mTc-MIBI imaging, with a diagnostic accuracy of 83.3% (5/6). Patients' postoperative serum calcium and serum parathyroid hormone (PTH) levels were normalized or significantly decreased from preoperative levels. Ultrasound combined with 99mTc-MIBI imaging can achieve higher accuracy than either examination alone in the preoperative localization and diagnosis of ETPG in SHPT patients.

How often are intrathyroidal parathyroid glands a cause of primary hyperparathyroidism, and how should they be managed?

BACKGROUND

The purpose of our study was to determine the frequency and management of intrathyroidal parathyroid glands in patients with primary hyperparathyroidism and evaluate whether intrathyroidal parathyroid glands were more often superior or inferior glands.

METHODS

A retrospective review of the prospective parathyroid database was completed to determine the number of patients with primary hyperparathyroidism and an intrathyroidal parathyroid gland. Demographic data, laboratory and localization studies, operative management, pathology, and outcome were determined for patients with an intrathyroidal parathyroid gland and were compared with patients with an extrathyroidal parathyroid gland.

RESULTS

From 1990-2023, 808 patients were operated on for primary hyperparathyroidism; 17 (2%) patients had an intrathyroidal parathyroid gland, an adenoma in 15 (88.2%), and a hyperplastic gland in 2 (11.8%). The mean age was 53 years; 16 (94%) patients were female. Mean calcium and parathyroid hormone was 12 mg/dL and 150 pg/mL, and there were no differences from the extrathyroidal parathyroid group. Ultrasound and Sestamibi imaging were valuable in identifying an intrathyroidal parathyroid gland in 10 of 13 patients and 13 of 17 patients, respectively. Local excision was performed in 9 (53%) patients and lobectomy in 8 (47%) patients. Intraoperative parathyroid hormone was measured and predictive of cure in 12 patients. The location of intrathyroidal parathyroid glands was determined in 15 patients and was inferior in 11 (73%). All patients were cured. No patient developed recurrent disease after a median 54-month follow-up.

CONCLUSION

Intrathyroidal parathyroid glands are the cause of primary hyperparathyroidism in 2% of patients and are most often inferior glands. Local excision was accomplished in 53% of our patients.

Distinguishing Intrathyroid Parathyroid Adenoma from Colloid Nodules and Papillary Thyroid Carcinomas Using Multiphasic Multidetector Computed Tomography

OBJECTIVE

The aim of the study is to determine whether multiphase multidetector computed tomography (4D-MDCT) can differentiate between intrathyroid parathyroid adenomas (ITPAs), colloid nodules, and papillary thyroid carcinoma (PTC).

METHODS

We studied 22 ITPAs, 22 colloid nodules, and 11 PTCs in 55 patients. Hounsfield unit (HU) values of the nodules were measured on 4D-MDCT in the precontrast, arterial, venous, and delayed phases. Raw HU values, phase with peak enhancement, and washout percentages between the phases were evaluated.

RESULTS

Regardless of size, all ITPAs (22/22) showed peak enhancement in the arterial phase, which was significantly greater than both colloid nodules (15/22) and PTC (6/11, P = 0.002); thus, nodules with peak enhancement in the venous or delayed phase were not ITPAs (specificity = 1). For nodules with peak enhancement in the arterial phase, the percentage washout in the arterial-to-venous phases separated ITPAs from PTC and colloid nodules (P < 0.001) with greater than or equal to 23.95% loss of HU value implying IPTA (area under curve, 0.79). This left a subset of colloid nodules or PTC that either peaked in the venous or delayed phase or had an arterial-to-venous phase washout of less than 23.95%. From this subset, PTC measuring 1 cm or greater could be separated from colloid based on HU values in the arterial phase with a cutoff HU value less than 81.4 for PTC (area under curve, 0.72) and an HU value greater than 164.5 suggested colloid.

CONCLUSIONS

Intrathyroid parathyroid adenomas can be distinguished from colloid nodules and PTC by peak enhancement in the arterial phase and rapid washout. A subset of colloid and PTC measuring 1 cm or greater can be separated using arterial phase HU values.

Diagnosis of Ectopic Intrathyroidal Parathyroid Adenoma with Nodular Goiter by 18F Fluorocholine: A Case Report

The occurrence of ectopic intrathyroidal parathyroid adenoma (EPTA) is very rare, which causes some difficulties in diagnosis and complicates treatment. In addition, the occurrence of EPTA with nodular goiter (NG) is rare, which makes diagnosis difficult and requires the assistance of clinical evidence, imaging data, and cytological examination results. Therefore, we present a patient with a final diagnosis of ETPA with NG.

[Medicolegal aspects of primary and renal hyperparathyroidism]

BACKGROUND

Compared with malpractice claims in thyroid surgery, expert medico-legal reviews of surgery performed for hyperparathyroidism (HPT) that aim to prove or rebut surgical malpractice are rare. The aim of this analysis was to describe typical risk patterns for possible treatment errors and to generate recommendations for avoiding these treatment errors.

MATERIAL AND METHODS

A total of 12 surgical expert medico-legal reviews, which were carried out by order of 9 arbitration boards and 3 courts between 1997 and 2020 were evaluated.

RESULTS

If the indications for surgical treatment of hyperparathyroidism were present, the failure to identify a parathyroid adenoma or hyperplastic parathyroid glands was in the majority of cases not rated as a surgical treatment error, especially in atypical localizations. Unilateral recurrent laryngeal nerve palsy and postoperative bleeding cannot always be prevented, despite maximum diligence. In contrast, bilateral recurrent laryngeal nerve palsy can be prevented when intraoperative neuromonitoring is correctly applied. A lack of patient information regarding postoperatively persistent HPT, postoperative hypoparathyroidism following the removal of inconspicuous parathyroid glands and nonindicated lobectomy or total thyroidectomy, mostly performed under the assumption of an intrathyroid parathyroid adenoma, represented avoidable malpractice issues.

CONCLUSION

Advanced knowledge of the pathophysiology of the disease and the anatomy of the parathyroid glands as well as the establishment of intraoperative and perioperative standards can prospectively greatly reduce avoidable errors in the surgical treatment and postoperative care of HPT.

The Value of Preoperative and Intraoperative Ultrasound in the Localization of Intrathyroidal Parathyroid Adenomas

AIM

Intrathyroidal parathyroid adenoma (IPA) is rare and may easily be mistaken for thyroid nodule in ultrasonography. The aim of this study was to investigate the characteristic features of IPA and explore the value of preoperative and intraoperative ultrasound in the diagnosis and localization of IPA.

METHODS

13 of 216 patients who were found to have intrathyroidal parathyroid lesions underwent parathyroidectomy in our hospital because of PHPT. According to the relationship between parathyroid adenoma and thyroid gland, parathyroid adenoma was divided into extra-thyroid type or intra-thyroid type (partial or complete) and the results were compared with surgical and histopathological reports as gold standard. The sonographic features of intrathyroidal parathyroid lesions were analyzed retrospectively.

RESULTS

A total of 12 intrathyroidal lesions showed profoundly hypoechoic solid nodules with well-defined border, abundant blood flow and polar feeding vessels originating from the superior or inferior thyroid artery (92.3%, 12/13). These nodules were finally confirmed as IPA (or IPAC) after surgery. Polar feeding vessel was not detected in one case of parathyroid hyperplasia confirmed by pathology (7.7%, 1/13). 12 cases were diagnosed and localized on ultrasonography before operation and 10 cases were localized on Tc-99m MIBI SPECT/CT.

CONCLUSIONS

The color Doppler ultrasound findings of IPA were confirmed as profoundly hypoechoic nodules with clear boundary and abundant internal blood flow. The presence of polar feeding vessels which originate from thyroid artery were identified as characteristic features of US for IPA. Preoperative and intraoperative ultrasound could be helpful in the localization and treatment of intrathyroidal parathyroid diseases.

Management of primary and renal hyperparathyroidism: guidelines from the German Association of Endocrine Surgeons (CAEK)

BACKGROUND AND AIMS

The purpose of this review is to provide updated recommendations for the surgical management of primary (pHPT) and renal (rHPT) hyperparathyroidism, formulating a new guideline of the German Association of Endocrine Surgeons (CAEK).

METHODS

Evidence-based recommendations for the diagnosis and therapy of pHPT and rHPT were assessed by a multidisciplinary panel using PubMed for a comprehensive literature search together with a structured consensus dialogue (S2k guideline of the Association of the German Scientific Medical Societies, AWMF).

RESULTS

During the last 20 years, a variety of new preoperative localization procedures, such as sestamibi-SPECT, 4D-CT, and various PET/CT procedures, were established for pHPT. High-resolution imaging, together with intraoperative parathyroid hormone (IOPTH) measurement, enabled focused or minimally invasive surgery to become the most favored surgical technique. Patients with pHPT and nonlocalizing imaging have a higher risk of multiglandular disease. Surgical therapy provides very high cure rates, with a clear relation to the surgeon's experience in parathyroid procedures. Reoperative parathyroidectomy, children with pHPT or familial forms, and parathyroid carcinoma are addressed and require special surgical expertise. A multidisciplinary team of experienced nephrologists, transplant, and endocrine surgeons should assess the diagnosis and treatment of renal HPT.

CONCLUSION

Surgery is the only curative treatment for pHPT and should be considered for all patients with pHPT. For rHPT, a more selective approach is required, and parathyroidectomy is indicated only when conservative treatment options fail. In parathyroid carcinoma, the adequacy of local resection influences local disease control.

A case of intrathyroid parathyroid tumor that was difficult to diagnose by ultrasonography

Background

With advances in diagnostic imaging such as ultrasonography (US), computed tomography (CT), and ^99mTc-MIBI-sestamibi (MIBI) scintigraphy, localized diagnosis of hyperparathyroidism (pHPT) has become possible with considerable accuracy. However, even with the use of these imaging techniques, since intrathyroid parathyroid tumors exist as a mass within the thyroid, it is often difficult to distinguish from thyroid masses. Although there have been various reports on US images of intraparathyroid tumors, we experienced a case with US images that were distinct from previous reports. Herein we present a case of an intrathyroid parathyroid adenoma (IPA) that was difficult to diagnose, with a main focus on US images.

Case presentation

A 53-year-old man with a diagnosis of hyperparathyroidism was referred to our department in December 2018. Ultrasonography revealed a tumor that was located in the inferior pole of the right lobe of the thyroid gland and no parathyroid mass was observed. The tumor had an irregular round shape and showed heterogeneous hyperechogenicity with a defined margin, but within it, there were a few irregular and hypoechogenic area with unclear margins, while the tumor had a mosaic appearance at first glance. Although ^99mTc-MIBI scintigraphy showed accumulation at the same location in delayed phase, it was difficult to determine the presence of a parathyroid tumor on the image. The patient underwent an operation on April 2019 and the tumor could not be identified on both naked eye and palpation. We used US intraoperatively to define the location and resected the tumor. A parathyroid adenoma was diagnosed by frozen section and the final diagnosis was an intrathyroid parathyroid adenoma.

Conclusion

We experienced an IPA presenting an US image that was atypical and has previously not been reported. IPA has no established US image to confirm the diagnosis and even with the use of other imaging techniques, a definitive diagnosis often cannot be established. Thus, our recommendation based on the current situation is that operation with intraoperative diagnosis using frozen section should be conducted if hypercalcemia and high I-PTH are observed and when localization sites in MIBI and US coincide.

Preventing blind thyroid lobectomy in patients with intrathyroidal hyperfunctioning parathyroid glands with radioguided enucleation

Aim: Hyperfunctioning intrathyroidal parathyroid glands are rare and often result in thyroid lobectomy. This study examines the utility of radioguided surgery to guide enucleation of intrathyroidal parathyroids. Methods: Between December 2002 and March 2018, 2291 patients underwent parathyroidectomy by one surgeon for primary hyperparathyroidism. A total of 74 (3%) patients had an ectopic intrathyroidal parathyroid gland and underwent radioguided. Results: All of intrathyroidal parathyroid glands were localized with the gamma probe. In vivo radionuclide counts were above 120% of the background in all but three patients. All intrathyroidal parathyroids were enucleated with the guidance of the gamma probe. Conclusion: Radioguided surgery is useful for intraoperative identification of hyperfunctioning, intrathyroidal parathyroid glands. This technique allows for enucleation of the abnormal parathyroid gland, avoiding thyroid lobectomy and preserving healthy thyroid parenchyma.

The role of 18F-FCH PET/CT in patients with uremic hyperparathyroidism compared with 99mTc-sestaMIBI SPECT/CT and ultrasonography

BACKGROUND

The aim of this study was to evaluate the diagnostic efficacy of ¹⁸F-fluorocholine (¹⁸F-FCH) PET/CT for uremic hyperparathyroidism (uHPT) compared to ^99mTc-sestaMIBI SPECT/CT and ultrasonography (US).

METHODS

A total of 17 uHPT patients with stage 5 chronic kidney disease (CKD) were prospectively enrolled. All patients underwent US, ^99mTc-sestaMIBI SPECT/CT, and ¹⁸F-FCH within 2 months and received surgical treatment. Visual and quantitative methods were used for image analyses. Intraoperative localization and postoperative histological results of the reference standard as well as the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of the three modalities were analyzed using Pearson's χ² tests. In addition, the diagnostic efficacy of ¹⁸F-FCH PET/CT for uHPT was evaluated. The relationships between PET parameters and laboratory parameters were assessed using the Spearman correlation coefficient.

RESULTS

A total of 63 parathyroid hyperplasia lesions were resected in 17 uHPT patients, and 53 lesions were detected using ¹⁸F-FCH PET/CT with no false-positive results. The sensitivity, specificity, accuracy, PPV, and NPV were 84.13%, 100%, 86.49%, 100%, and 52.38%, respectively. In comparison, the corresponding values for ^99mTc-sestaMIBI SPECT/CT and US were 63.49%, 90.91%, 67.57%, 97.56%, and 30.30% and 61.90%, 81.82%, 64.86%, 95.12%, and 27.27%, respectively. The volume of hyper-functioning parathyroid glands was significantly different between lesions positive in ¹⁸F-FCH PET/CT and negative in ¹⁸F-FCH PET/CT (mean volume 1.36 ± 0.55 cm³ vs. 0.83 ± 0.26 cm³; P = 0.019). US misidentified intrathyroidal parathyroid hyperplasia as thyroid nodules in three patients, while ¹⁸F-FCH PET correctly identified the anatomy. No significant associations were observed between PET parameters and laboratory parameters in uHPT.

CONCLUSION

¹⁸F-FCH PET/CT was more sensitive and accurate for uHPT than ^99mTc-sestaMIBI SPECT/CT and US, and had better preoperative diagnostic efficacy, particularly for lesions diagnosed as a thyroid nodule by US.

Simultaneous intrathyroidal parathyroid adenomas and multifocal papillary thyroid carcinoma in a patient with kidney transplantation: a case report

BACKGROUND

Persistent hyperparathyroidism after kidney transplantation has been associated with adverse outcomes. Parathyroidectomy is the definitive treatment approach, but the success of parathyroidectomy relies on the accurate preoperative localization of the culprit parathyroid lesions. Simultaneous intrathyroidal parathyroid adenomas and multifocal papillary thyroid carcinoma present important diagnostic challenges. Here, we describe a patient with kidney transplantation who underwent successful surgery after being evaluated with functional and structural imaging.

CASE PRESENTATION

A 53-year-old man presented with potentially malignant multifocal thyroid nodules by ultrasonography 2 years after kidney transplantation. The patient had hypercalcaemia and persistent hyperparathyroidism. Thyroid papillary carcinoma was confirmed in the left thyroid nodules by fine-needle aspiration biopsy. The right superior thyroid hypoechoic nodule was 1.2 cm in size and showed marked uptake of the tracer ^99mTcO₄-sestamibi during single-photon emission computed tomography/computed tomography (SPECT/CT); additionally, a cystic parathyroid lesion without tracer uptake was present behind the left superior pole of the thyroid. The histological examination demonstrated the coexistence of right intrathyroidal parathyroid adenomas, left cystic parathyroid nodular hyperplasia and multifocal papillary thyroid carcinoma. At the 6-month follow-up, the serum calcium levels were within the normal range, and the patient's kidney function remained stable.

CONCLUSIONS

Simultaneous intrathyroidal parathyroid adenomas and multifocal papillary thyroid carcinoma in a patient with kidney transplantation is a rare clinical scenario. Physicians must be aware that the combination of functional (SPECT/CT) and structural (ultrasonography) imaging is highly successful in diagnosing patients with coexistent intrathyroidal parathyroid adenomas and papillary thyroid carcinoma.

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.

Usefulness of preoperative ultrasonographic localization for diagnosis of a rare disease: Intrathyroid parathyroid lesions

The aim of this article is to explore the value of ultrasonic diagnosis and localization of intrathyroid parathyroid diseases.The medical records of 15 patients with surgically confirmed intrathyroid parathyroid diseases were reviewed. We analyzed the diagnosis process and recorded sonographic features of these intrathyroid parathyroid lesions.The patients included 11 females (73%, 11/15) and 4 males (27%, 4/15) with a mean age of 46.2 ± 10.2 years and a mean lesion size of 2.1 ± 1.1 cm. A total of 11 intrathyroid parathyroid lesions in this study presented as hypoechoic (73.3%, 11/15). Nine lesions were located in the right lobe of the thyroid (60%, 9/15), and most of the lesions were located in the middle and inferior thyroid (80%, 12/15). All of the 15 intrathyroid parathyroid lesions were variable in shape and well defined. Only 1 lesion showed microcalcification, which was confirmed as parathyroid adenocarcinoma by the postoperative pathological diagnosis. The blood supply of 13 lesions was plentiful (86.7%, 13/15). A hyperechoic line on the parathyroid lesion was detected in 13 lesions (86.7%, 13/15). Based on the degree to which the parathyroid gland was embedded in the thyroid gland, 12 cases were classified as the complete type (80%, 12/15), and 3 cases were classified as the incomplete type (20%, 3/15). Ultrasound was used to diagnose 10 cases, and sestamibi-SPECT was used to diagnose 11 cases preoperatively; the 2 imaging methods were complementary.Ultrasonic preoperative localization could be helpful in the diagnosis and management of intrathyroid parathyroid diseases.

Fine-needle aspiration cytology of parathyroid carcinoma mimic hürthle cell thyroid neoplasm

Background. Fine-needle aspiration (FNA) can cause misdiagnosis of cytomorphological findings between parathyroid and thyroid lesions. Case Presentation. A 31-year-old man presented with a palpable neck mass on the right thyroid lobe. FNA cytology was reported as intrathyroidal lymphoid hyperplasia. After 5 years, repeated FNA was done on the enlarged nodule with result of Hürthle cell lesion. Prior to right lobectomy, laboratories revealed elevated serum calcium and parathyroid hormone (PTH). Careful history taking revealed chronic knee pain and ossifying fibroma at the maxilla. Ultrasonography showed a 2.8 cm mass inferior to right thyroid lobe. Pathology from en bloc resection was parathyroid carcinoma and immunohistochemical study revealed positivity for PTH. Genetic analysis found somatic mutation of CDC73 gene in exon1 (c.70delG) which caused premature stop codon in amino acid 26 (p.Glu24Lysfs*2). The final diagnosis was hyperparathyroidism-jaw tumor syndrome. Conclusions. FNA cytology of parathyroid can mimic thyroid lesion. It is important to consider and correlate the entire information from clinical history, laboratory, imaging, and FNA.

Role of ultrasonography in the management of patients with primary hyperparathyroidism: retrospective comparison with technetium-99m sestamibi scintigraphy

OBJECTIVE

Primary hyperparathyroidism (PHPT) is a common endocrine disorder that can be cured only by parathyroidectomy. Cervical ultrasonography and scintigraphy are the imaging studies most widely used for preoperative localization of the affected glands. The aim of this retrospective comparative study was to define the respective roles of ultrasonography and parathyroid scintigraphy in these cases.

MATERIALS AND METHODS

We analyzed 108 patients who had undergone parathyroidectomies for PHPT following cervical ultrasonographic and scintigraphic examinations. The ultrasound examinations were carried out by an expert physician sonographer in 61 cases and by various physician sonographers with different levels of experience in 47 cases. Sonographic and scintigraphic findings were compared with surgical findings and the diagnostic performance of the two imaging methods was evaluated by means of statistical analysis.

RESULTS

The operator dependency of ultrasonography was confirmed by marked variations in sensitivity related to the experience of the sonographer. When sonography was performed by an expert, the sensitivity of combined use of the two methods was not significantly higher than that of sonography alone.

CONCLUSIONS

In expert hands, the diagnostic yield of ultrasound is appreciably superior. It can therefore be used as the main and possibly sole method for preoperative localization of pathological parathyroid tissues. Combined use of ultrasound and scintigraphy is not cost-effective in these cases. Scintigraphy is indicated only when the ultrasound examination produces negative results.