Variable sonographic spectrum of parathyroid adenoma with a novel ultrasound finding: dual concentric echo sign

Sonographic Features of Atypical and Initially Missed Parathyroid Adenomas: Lessons Learned From a Single-Center Cohort

CONTEXT

Awareness of typical and atypical ultrasonographic (US) features of parathyroid adenomas (PAs) is crucial since US is the most widely used first-line imaging modality.

OBJECTIVE

The purpose of this study was to describe the atypical features of PAs on US and other possible factors leading to a false negative examination in a large single-center cohort.

MATERIALS AND METHODS

The US records of 457 PAs in 445 patients with biochemically proven primary hyperparathyroidism (PHPT) were evaluated in a prospectively maintained database. Atypical size, composition, shape, echogenicity, location, and vascular pattern on US were noted. For patients who previously had at least one negative US examination in referring centers, the main possible reason was defined accordingly.

RESULTS

The study group included 359 female and 86 male patients with PHPT. Typical sonographic features were observed in 231 PAs (51%), whereas 226 (49%) had at least one atypical US feature. The most common atypical features were atypical size (29%), followed by atypical echogenicity (19%), shape (8%), location (7%), and composition (7%), respectively. There were 122 initially missed PAs in all groups. The most frequent main atypical US features leading to false negative examinations were atypical size (22.1%) and atypical location (18.8%). Inexperience was third most common reason (16.3%) for false negative US examinations.

CONCLUSIONS

Almost half of PAs have at least one atypical feature on US. Awareness of the high prevalence of atypical US features could increase the accuracy of US examination and potentially decrease demand for more expensive second-line imaging modalities.

The Dark Side of Ultrasound Imaging in Parathyroid Disease

The diagnosis of parathyroid diseases by imaging still has some intrinsic technical limitations due to the differential diagnosis of different structures of the neck that mimic the parathyroid glands. In this view, ultrasound (US) is an established, low-cost, and non-invasive imaging technique that still represents the first-line approach for evaluating patients with parathyroid disease. The objective of this article is to provide a comprehensive review of the applications of USs in clinical practice, discussing the histopathological and US characteristics of the parathyroid glands in normal and pathological conditions, the advantages of preoperative imaging, and novel updates on the most useful and currently available multiparameter US techniques.

Contrast-Enhanced Ultrasound Qualitative and Quantitative Characteristics of Parathyroid Gland Lesions

Background and Objectives: preoperative differentiation of enlarged parathyroid glands may be challenging in conventional B-mode ultrasound. The aim of our study was to analyse qualitative and quantitative characteristics of parathyroid gland lesions, using multiparametric ultrasound protocol—B-mode, Colour Doppler (CD), and contrast-enhanced ultrasound (CEUS)—and to evaluate correlation with morphology in patients with hyperparathyroidism (HPT). Materials and Methods: consecutive 75 patients with 88 parathyroid lesions and biochemically confirmed HPT prior to parathyroidectomy were enrolled in the prospective study. B-mode ultrasound, CD, and CEUS were performed with the subsequent qualitative and quantitative evaluation of acquired data. We used 1 mL or 2 mL of intravenous ultrasound contrast agent during the CEUS examination. Correlation with post-surgical morphology was evaluated. Results: seventy parathyroid adenomas were hypoechoic and well contoured with increased central echogenicity (44.3%), peripheral-central vascularization (47%), and polar feeding vessel (100%). Twelve hyperplasias presented with similar ultrasound appearance and were smaller in volume (p = 0.036). Hyperplasias had a tendency for homogenous, marked intense enhancement vs. peripherally enhanced adenomas with central wash-out in CEUS after quantitative analysis. No significant difference was observed in contrasting dynamics, regardless of contrast media volume use (1 mL vs. 2 mL). We achieved 90.9% sensitivity and 72.7% specificity, 93% positive predictive value (PPV), 87.3% negative predictive value (NPV), and 87.3% accuracy in the differentiation of parathyroid lesions prior to post-processing. In a quantitative lesion analysis, our sensitivity increased up to 98%, specificity 80%, PPV 98%, and NPV 80% with an accuracy of 96.4%. Conclusions: CEUS of parathyroid lesions shows potential in the differentiation of adenoma from hyperplasia, regardless of the amount of contrast media injected. The quantitative analysis improved the sensitivity and specificity of differentiation between parathyroid lesions. Hyperplasia was characterized by homogeneous enhancement, fast uptake, and homogeneous wash-out appearance; adenoma—by peripheral uptake, central wash-out, and reduced hemodynamics. The use of CEUS quantification methods are advised to improve the ultrasound diagnostic role in suspected parathyroid lesions.

Enlarged parathyroid glands with variable sonomorphology in a case of tertiary hyperparathyroidism: Sonographic-histopathologic correlation

The typical sonomorphology of homogeneously hypoechoic texture of an enlarged parathyroid gland (PG) is a reflection of uniform arrangement of the parathormone-producing chief cells. A variable cellular arrangement, hemorrhage, fibrosis, and adipocytes cause heterogeneous appearance. We describe a case of a 32-year-old male, a case of tertiary hyperparathyroidism, with increased serum parathormone levels, hypercalcemia, and enlargement of all four PGs, albeit with differing morphology. The left lower gland had two nodules, namely, superior and inferior. The inferior nodule of the left lower gland had an echogenic core surrounded by a sonolucent rim whereas the superior nodule was homogenously hyoechoic. The left upper gland had an echopattern exactly reverse of the inferior nodule of the left lower PG, i.e., hypoechoic gland surrounded by hyperechoic periphery. The appearance of the right-sided glands was that of the superior nodule of the left lower PG. On histopathology, the hypoechoic areas corresponded to numerous chief cells and congested vessels whereas edema gave rise to an increase in echogenicity. This report exemplifies atypical sonographic appearances of PG and their histopathologic correlation.

Mapping of parathyroid neoplasms based on grey scale ultrasound images and histopathological whole slide images

PURPOSE

In this study, echogenicity and histopathological projections of parathyroid neoplasia in grey mode ultrasonography were compared with whole side imaging (WSI). The utility of the data obtained for clinical assessment was evaluated.

METHODS

In 57 patients operated for hyperparathyroidism, the parathyroid gland was sampled in the sagittal plane. The lesion slides were scanned. The WSI was rendered digital. The histopathological slide images scanned with USG images were matched. With the İmage J program, the areas of cell types and morphological changes were measured.

RESULTS

In parathyroid neoplasms, hypoechoic areas were found to be matched with 21% [55.3%] chief cell, 2 [5.0%] oncocytic cell and 8%[20.0%] cystic morphology. Of the 57 patients, 26 [45.61%] had a cystic area. It was seen that hyperechogenic areas match more connective tissue areas than chef cell [p < 0.05]. There was less clear cell in hyperechogenic areas than iso-hyperechogenic areas [p < 0.05]. The ratio of fat tissue echogenicity was lower in hypoechoic areas than hyperechoic [p < 0.05]. There was a positive correlation between PTH and the entire tissue area [r = 0.377, p = 0.004]. A positive directional moderate linear relationship was found between blood calcium level and parathyroid adenoma [rho = 0.530, p = 0.009] and percentage [rho = 0.416, p = 0.048]. When atypical adenomas and adenoma cases were compared, no significant difference was found between the cystic and chief cell areas [p > 0.05].

CONCLUSION

The hypoechogenicity seen in USG was observed to be compatible with chief cell, hyperechogenic areas in USG were compatible with connective tissue and fat tissue. As the cystic area increased, blood calcium levels were higher in adenomas. We think that the results of this study will be guiding to evaluate the reflections of the detailed morphometric studies.

Added value of ultrasonography and Tc-99m MIBI SPECT/CT combined protocol in preoperative evaluation of parathyroid adenoma

•

Concomitant use of ultrasonography and MIBI-SPECT/CT is highly recommended for better depiction of parathyroid adenoma.

•

It also helps in accurate localization of parathyroid adenoma especially those of ectopic location.

•

It will provide better success for parathyroid exploration and minimally invasive surgery.

Purpose

Evaluating the diagnostic performance of combined protocol of ultrasonography and Tc-99 m MIBI SPECT/CT in preoperative depiction and localization of parathyroid adenoma.

Methods and materials

60 patients were enrolled in this retrospective study who had primary hyperparathyroidism and parathyroidectomy for parathyroid adenoma, all of them underwent ultrasonography examination of parathyroid gland and MIBI SPECT/CT for exact pre-operative localization of parathyroid adenoma, surgical and pathological results were used as standard reference then sensitivity, specificity and accuracy for each modalility and for combined protocol of both modalities was calculated.

Results

The sensitivity, specificity and accuracy were highest with combined protocol of ultrasonography and MIBI-SPECT/CT (87 %), (71 %) and (85 %) respectively and lowest sensitivity, specificity and accuracy with ultrasonography alone (76 %), (63 %) and (73 %) respectively while (83 %), (66 %) and (80 %) with MIBI-SPECT/CT alone.

Conclusion

Concomitant use of ultrasonography and MIBI SPECT/CT is highly recommended for better preoperative depiction and localization of parathyroid adenoma.

A new tool for diagnosing parathyroid lesions: angio plus ultrasound imaging

Background

Our aim was to examine the potential value of angio plus ultrasound imaging in diagnosing parathyroid lesions. Angio plus ultrasound imaging uses a new paradigm in Doppler performance, which allows for a better detection of flow in small vessels while maintaining workflow of conventional color flow imaging characteristics.

Methods

Thirty parathyroid lesions, composed of 26 histopathologically diagnosed adenoma and 4 hyperplasia (two hyperplasia in the same patient), from 29 consecutive patients (6 men and 23 women; median age: 53 years, range: 25-78 years) were evaluated using both color Doppler and angio plus ultrasound imaging. The polar vessel (visible or invisible), number and distribution (peripheral, central, and both) of blood flow signals were compared between the two techniques.

Results

On color Doppler, the polar vessel was visible in 6 (20%) lesions. The median number of blood flow signals was 6 [3-23]. The distribution of peripheral, central and both was shown in 4 (13.3%), 9 (30%), and 15 (50%) lesions respectively, and no blood signals was shown in 2 (6.7%) lesions. On angio plus ultrasound imaging, the polar vessel was visible in 16 (53.3%) lesions. The median number of blood flow signals was 3 [0-18]. The distribution of peripheral, central and both was shown in 1 (3.3%), 4 (13.3%), and 25 (83.3%) lesions respectively. There was significant difference between color Doppler and angio plus ultrasound imaging in the detection of the polar vessel, number and distribution of blood flow signals.

Conclusions

The typical polar vessel and increased vascularity commonly associated with parathyroid lesions may be obtained with angio plus ultrasound imaging. Angio plus ultrasound imaging can improve the detection rate and distribution characteristics of blood flow signals of parathyroid lesions. Further research is needed to clarify the clinical meaning of increased blood flow information, such as the differentiation of parathyroid lesions from other lesions.

Study of the Ultrasound Appearance of the Normal Parathyroid Using an Intraoperative Procedure

OBJECTIVES

This study was designed to confirm the echogenicity of normal parathyroid glands using intraoperative ultrasound (US).

METHODS

Between October 2015 and January 2016, normal parathyroid glands were examined with an intraoperative US transducer during thyroidectomy procedures in 13 patients with thyroid disease. According to the findings from intraoperative US, routine percutaneous US of normal parathyroid glands was performed in a group of adults. On the basis of previous information on normal parathyroid echogenicity, a series of parathyroid diseases that were proved by surgery and histopathologic analyses were retrospectively reviewed. The presence of residual normal parathyroid in the lesion on US imaging, which was defined as the residual parathyroid sign in this study, was reviewed and correlated with histopathologic results.

RESULTS

In the intraoperative US group, 23 parathyroid glands were scanned intraoperatively, and 21 (91.3%) were hyperechoic, homogeneous in texture, and oval. In the routine percutaneous US group, 106 parathyroid glands were found in total, and 96 (90.5%) of the glands had hyperechoic and homogeneous echogenicity, with 75 (70.8%) being oval. In the review of parathyroid diseases, 33 parathyroid glands in 30 cases were reviewed, with a positive residual parathyroid sign in 7 (21.2%) parathyroid glands, presenting with a hyperechoic rim in the margin, and 4 of them (12.1%) were confirmed by histopathologic results.

CONCLUSIONS

The normal parathyroid had hyperechoic echogenicity on both intraoperative and percutaneous US imaging. Residual tissue of parathyroid glands can also be observed in some parathyroid abnormalities with an echogenic appearance on US imaging and confirmed by histopathologic results.

The role of ultrasound and nuclear medicine methods in the preoperative diagnostics of primary hyperparathyroidism

Primary hyperparathyroidism (PH) represents one of the most common endocrine diseases. In most cases, the disorder is caused by parathyroid adenomas. Bilateral neck exploration has been a widely used treatment method for adenomas since the 20's of the twentieth century. In the last decade, however, it has been increasingly replaced by a minimally invasive surgical treatment. Smaller extent, shorter duration and lower complication rate of such a procedure are emphasized. Its efficacy depends on a precise location of parathyroid tissue during the preoperative imaging. Scintigraphy and ultrasound play a major role in the diagnostic algorithms. The efficacy of both methods has been repeatedly verified and compared. The still-current guidelines of the European Association of Nuclear Medicine (2009) emphasize the complementary role of scintigraphy and ultrasonography in the preoperative diagnostics in patients with primary hyperparathyroidism. At the same time, attempts are made to improve both these techniques by implementing new study protocols or innovative technologies. Publications have emerged in the recent years in the field of ultrasonography, whose authors pointed out the usefulness of elastography and contrast media. Nuclear medicine studies, on the other hand, focus mainly on the assessment of new radiotracers used in the positron emission tomography (PET). The aim of this article is to present, based on literature data, the possibilities of ultrasound and scintigraphy in the preoperative diagnostics in patients with primary hyperparathyroidism. Furthermore, the main directions in the development of imaging techniques in PH patients were evaluated.