Relative risk of cancer in sonographically detected thyroid nodules with calcifications

The auxiliary diagnosis of thyroid echogenic foci based on a deep learning segmentation model: A two-center study

OBJECTIVE

The aim of this study is to develop AI-assisted software incorporating a deep learning (DL) model based on static ultrasound images. The software aims to aid physicians in distinguishing between malignant and benign thyroid nodules with echogenic foci and to investigate how the AI-assisted DL model can enhance radiologists' diagnostic performance.

METHODS

For this retrospective study, a total of 2724 ultrasound (US) scans were collected from two independent institutions, encompassing 1038 echogenic foci nodules. All echogenic foci were confirmed by pathology. Three DL segmentation models (DeepLabV3+, U-Net, and PSPNet) were developed, with each model using two different backbones to extract features from the nodular regions with echogenic foci. Evaluation indexes such as Mean Intersection over Union (MIoU), Mean Pixel Accuracy (MPA), and Dice coefficients were employed to assess the performance of the segmentation model. The model demonstrating the best performance was selected to develop the AI-assisted diagnostic software, enabling radiologists to benefit from AI-assisted diagnosis. The diagnostic performance of radiologists with varying levels of seniority and beginner radiologists in assessing high-echo nodules was then compared, both with and without the use of auxiliary strategies. The area under the receiver operating characteristic curve (AUROC) was used as the primary evaluation index, both with and without the use of auxiliary strategies.

RESULTS

In the analysis of Institution 2, the DeepLabV3+ (backbone is MobileNetV2 exhibited optimal segmentation performance, with MIoU = 0.891, MPA = 0.945, and Dice = 0.919. The combined AUROC (0.693 [95% CI 0.595-0.791]) of radiology beginners using AI-assisted strategies was significantly higher than those without such strategies (0.551 [0.445-0.657]). Additionally, the combined AUROC of junior physicians employing adjuvant strategies improved from 0.674 [0.574-0.774] to 0.757 [0.666-0.848]. Similarly, the combined AUROC of senior physicians increased slightly, rising from 0.745 [0.652-0.838] to 0.813 [0.730-0.896]. With the implementation of AI-assisted strategies, the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of both senior physicians and beginners in the radiology department underwent varying degrees of improvement.

CONCLUSIONS

This study demonstrates that the DL-based auxiliary diagnosis model using US static images can improve the performance of radiologists and radiology students in identifying thyroid echogenic foci.

An optimized and highly repeatable MRI acquisition and processing pipeline for quantitative susceptibility mapping in the head-and-neck region

PURPOSE

Quantitative Susceptibility Mapping (QSM) is an emerging technique sensitive to disease-related changes including oxygenation. It is extensively used in brain studies and has increasing clinical applications outside the brain. Here we present the first MRI acquisition protocol and QSM pipeline optimized for the head-and-neck region together with a repeatability analysis performed in healthy volunteers.

METHODS

We investigated both the intrasession and the intersession repeatability of the optimized method in 10 subjects. We also implemented two, Tikhonov-regularisation-based susceptibility calculation techniques that were found to have higher contrast-to-noise than existing methods in the head-and-neck region. Repeatability was evaluated by calculating the distributions of susceptibility differences between repeated scans and the corresponding minimum detectable effect sizes (MDEs).

RESULTS

Deep brain regions had higher QSM repeatability than neck regions. As expected, intrasession repeatability was generally better than intersession repeatability. Susceptibility maps calculated using projection onto dipole fields for background field removal were more repeatable than using the Laplacian boundary value method in the head-and-neck region. Small (short-axis diameter <5 mm) lymph nodes had the lowest repeatability (MDE = 0.27 ppm) as imperfect segmentation included some of the surrounding paramagnetic fatty fascia, highlighting the importance of accurate region delineation. MDEs in the larger lymph nodes (0.16 ppm), submandibular glands (0.10 ppm), and especially the parotid glands (0.06 ppm) were much lower, comparable to those of the brain regions.

CONCLUSIONS

The high repeatability of the acquisition and pipeline optimized for QSM will facilitate clinical studies in the head-and-neck region.

Nodule Size Effect on Diagnostic Performance of Ultrasonography and Computed Tomography for Papillary Thyroid Carcinoma

BACKGROUND

To compare the abilities of ultrasonography (US) and Computed Tomography (CT) to identify calcifications and to predict probability of malignancy for Papillary Thyroid Carcinoma (PTC) and Papillary Thyroid Microcarcinoma (PTMC).

METHODS

We reviewed 1008 cases of PTC/PTMC with calcifications reported by pre-operative US, CT, or post-operative pathology. The size of the thyroid nodule was obtained from the US report and the maximum diameter (d) was documented. According to the nodule size (d), the PTC and PTMC groups were each divided into two subgroups, as follows: large PTC group (d ≥ 2 cm), small PTC group (1 cm < d < 2 cm), large PTMC group (0.6 cm ≤ d ≤ 1 cm), and small PTMC group (d < 0.6 cm).

RESULTS

In the 1008 patients, the ratio of females to males was 2.29 and the mean age was 40.9 years (standard deviation: 11.7 years). Of the 1008 records, 92.8% were found to have calcifications according to the US report, while 50.4% showed calcifications according to the CT report. This difference between US and CT reports was statistically significant (p < 0.0005). The percentages of US reports showing calcifications were similar for all four PTC and PTMC subgroups (93.7%, 94.3%, 92.1%, and 85.1%, respectively; p = 0.052), while the percentages of CT reports showing calcifications were significantly different among the PTC and PTMC subgroups (62.3%, 52.2%, 45.4%, and 31.3%, respectively; p < 0.0005). As for the prediction of malignancy, US was superior to CT in all four subgroups (large PTC group: 97.1% vs. 54.1%, small PTC group: 94.8% vs. 42.9%, large PTMC group: 97.2% vs. 32.0%, small PTMC group: 95.5% vs. 14.9%; p < 0.0005 for all pairwise comparisons). No significant difference was observed in terms of the ability of US to predict the malignancy of PTC versus PTMC (p = 0.31), while CT showed significant superiority in diagnosing PTC versus PTMC (p < 0.0005). The predictive value of CT for PTC declined as the nodule size decreased (p < 0.05 for all pairwise comparisons).

CONCLUSION

Our results showed that US detected calcifications and predicted the malignancy of all nodule sizes of thyroid papillary carcinoma equally well, while the performance of CT declined with the reduction of nodule size.

Comparison of Ultrasonography and CT for Determining the Preoperative Benign or Malignant Nature of Thyroid Nodules: Diagnostic Performance According to Calcification

Background:

The present study was designed to investigate the presence or absence of calcification and whether calcification size affect the diagnostic accuracy of ultrasonography (US) and computed tomography (CT) in predicting the benign or malignant nature of thyroid nodules.

Material and Methods:

From May 2014 to April 2019, 445 patients underwent thyroid US and neck CT before thyroid surgery. In each case, US and CT were retrospectively examined by radiologists. We divided the patients into 3 groups according to the type of calcification: no calcification, microcalcification, and macrocalcification. And macrocalcification group divided into rim calcifications and non-rim calcifications groups. We evaluated the diagnostic accuracy of US and CT for differentiating malignant from benign thyroid nodules using histopathological results as a reference standard.

Results:

In the overall population, adding CT to US resulted in greater sensitivity, lower specificity, and lower accuracy in the prediction of the benign or malignant nature of nodules. In the group with no calcification, US had a significantly greater accuracy than CT and combined US/CT. In the group with macrocalcification, especially in rim calcifications, adding CT to US resulted in greater sensitivity than US, and CT exhibited greater sensitivity and accuracy than US.

Conclusion:

US is superior to CT for the prediction of the benign or malignant nature of nodules in thyroid lesions according to calcification and CT is also currently not recommended as a routine imaging tool for thyroid nodules. However, the superior sensitivity and accuracy of CT in lesions with macrocalcification especially in rim calcifications may enable CT to play a complementary role in identifying benign and malignant nodules.

The Role of Sclerostin in Bone and Ectopic Calcification

Sclerostin, a 22-kDa glycoprotein that is mainly secreted by the osteocytes, is a soluble inhibitor of canonical Wnt signaling. Therefore, when present at increased concentrations, it leads to an increased bone resorption and decreased bone formation. Serum sclerostin levels are known to be increased in the elderly and in patients with chronic kidney disease. In these patient populations, there is a high incidence of ectopic cardiovascular calcification. These calcifications are strongly associated with cardiovascular morbidity and mortality. Although data are still controversial, it is likely that there is a link between ectopic calcification and serum sclerostin levels. The main question, however, remains whether sclerostin exerts either a protective or deleterious role in the ectopic calcification process.

Relationship Between Morphologic Characteristics of Ultrasonic Calcification in Thyroid Nodules and Thyroid Carcinoma

The aim of this study was to investigate the relationship between morphologic characteristics of the calcifications detected by ultrasound in thyroid nodules and thyroid carcinoma. Morphologic characteristics of the calcifications on pre-operative ultrasound examinations of thyroids were compared with post-operative pathologic diagnoses in 543 patients undergoing thyroid surgery. Calcifications were divided into microcalcifications (≤2 mm) and macrocalcifications (>2 mm), and the latter were divided into eggshell calcifications in a row, eggshell discontinuous calcifications, irregular calcifications and multilayer-like calcifications, labeled types I-V. We found that thyroid microcalcifications and partial macrocalcifications, such as eggshell discontinuous calcifications, and multilayer-like calcifications were associated with thyroid carcinoma. In conclusion, microcalcifications were more commonly found in malignant thyroid nodules, particularly in papillary thyroid carcinoma. Eggshell discontinuous macrocalcifications and multilayer-like macrocalcifications also occurred mainly in malignant nodules.

NEW PROPOSED FORMULA OF TI-RADS CLASSIFICATION BASED ON ULTRASOUND FINDINGS

Introduction

The present study aimed to introduce a new formula for classification of nodules in TI-RADS and describe ultrasonography features of benign and malignant thyroid nodules.

Methods

This study was conducted on thyroid mass in 1033 patients. The incidence of malignancy for thyroid nodules was determined by selecting malignancy coefficients. Then the patients were first classified using conventional TI-RADS classification criteria and once again according to a new proposed formula.

Results

Among ultrasonography features of thyroid nodules, the irregular shape (46.7%), unclear margin (47.3%), extension to the capsule (irregular and infiltrative margin) (85%), the marked hypo-echoic nodules (63.8%), micro-calcification (49%), and to have vertical axis (74.0%) were associated with high incidence of malignancy.

Conclusion

According to the proposed new formula for TI-RADS, there are four coefficients of 7, 3, 1 and 0 for incidence of malignancy of each one of ultrasound findings that help to standardization and unifying of TI-RADS classification. The incidence of malignancy in TI-RADS classification according to the new proposed formula was achieved as follows: group 2: 0.0%, group 3: 0.7%, groups 4a, 4b, 4c: 16.7%, 43.4%, 68.5%, and group 5: 95.2%, respectively.

A New Imaging Technique for the Diagnosis of Thyroid Cancer: Thyroidography

Background: Microcalcifications are the most important diagnostic parameter for thyroid cancer. We developed a new imaging technique based on low dose X-rays that specifically reveal microcalcifications via a new software algorithm. Method: A prospective clinical trial was planned and 45 cases (37 women, 8 men, women/men: 4.6, age range: 17-68, mean age: 43) were included in the study. After total thyroidectomy with standard technique, the fresh thyroid tissues were integrated into the human neck simulator. Raw (DICOM) images were obtained for each tissue sample with a standard mammography device and transformed into new images (thyroidograms) by a new software algorithm. Preoperative ultrasonography (USG) images, DICOM images, and thyroidograms were evaluated in order to observe micro and macrocalcifications by the same experienced radiologist. Results: Twenty-four cases were malignant and 21 cases were benign after histopathologic evaluation. Microcalcification detection with the thyroidography was statistically significant for sensitivity, positive predictive value, negative predictive value, and accuracy (p < 0.05) but not for specificity (p > 0.05) compared to the USG and DICOM images for the malignant and also benign cases. Conclusion: This new imaging technique is hopeful for diagnosis of thyroid cancer according to microcalcification detection and may complement thyroid USG.

Echogenic foci in thyroid nodules: diagnostic performance with combination of TIRADS and echogenic foci

Background

The malignancy risks of various echogenic foci in thyroid nodules are not consistent. The association between malignancy and echogenic foci and various Thyroid Imaging Reporting and Data System (TIRADS) in thyroid nodules has not been evaluated. We evaluated the malignancy probability and diagnostic performance of thyroid nodules with various echogenic foci and in combination with TIRADS.

Methods

This retrospective study was approved by Institutional Review Board. The data were retrospectively collected from January 2013 to December 2014. In total, 954 patients (mean age, 50.8 years; range, 13–86 years) with 1112 nodules were included. Using χ² test, we determined the prevalence of benign and malignant nodules among those with and without echogenic foci; we associated each of 6 echogenic foci types with benign and malignant nodules. Diagnostic performance was compared between the 6 types alone and in combination with various TIRADS.

Results

Among 1112 nodules, 390 nodules (35.1%) were found to have echogenic foci, and 722 nodules (64.9%) were not. Among nodules with echogenic foci, 254 nodules (65.1%) were malignant. The punctate echogenic foci with comet-tail artifact showed malignancy rate of 77.8% in solid and predominantly solid nodules. Our study demonstrated relatively low PPV (33.3–56.4%) in nodules with large echogenic foci without shadowing, macrocalcification, and peripheral curvilinear or eggshell echogenic foci with or without shadowing. However, when combined with high suspicion category of TIRADS, PPV increased to 50.0–90.9%.

Conclusion

Combination with TIRADS with different types of echogenic foci offer better stratification of the malignancy risk.

Electronic supplementary material

The online version of this article (10.1186/s12880-019-0328-2) contains supplementary material, which is available to authorized users.

Diagnostic accuracy of ultrasound characteristics in the identification of malignant thyroid nodules

Objective

This study was aimed at determining the diagnostic accuracy of the ultrasound characteristics in the identification of malignant thyroid nodules in patients attending the surgical clinic at a tertiary care hospital in Sri Lanka.

Results

This prospective validation study was conducted among 263 patients attending the surgical clinic at a tertiary care hospital, Sri Lanka. The ultrasound characteristics having statistically significant associations with thyroid malignancies were identified by employing a multivariable analysis. These ultrasound characteristics were compared with Fine Needle Aspiration Cytology results and indicators of diagnostic accuracy were computed. The study sample consisted of 33 malignant and 230 benign nodules. Internal vascularity, hypoechogenicity and microcalcification showed statistically significant positive associations with thyroid malignancy (p < 0.05). The highest positive likelihood ratio was observed for the presence of microcalcifications (10.4, 95% CI 4.6–23.7) with a specificity of 96.5% (95% CI 93.3–98.5%). Hypoechogenicity had a sensitivity of 66.7% (95% CI 48.2–82.0%) and a specificity of 74.8% (95% CI 68.6–80.3%). The presence of at least one positive ultrasound characteristic yielded the highest sensitivity (87.9%, 95% CI 71.8–96.6%), whereas, the presence of all three characteristics yielded a near perfect specificity (99.6%, 95% CI 97.6–99.9%). Hence, the presence of microcalcifications was found to be the single most useful criterion in predicting thyroid malignancy.

Relationship between ultrasonographic and pathologic calcification patterns in papillary thyroid cancer

Ultrasonographic microcalcification is highly related to papillary thyroid cancer (PTC) and pathologic psammoma body is a poor prognostic factor. However, it is little known about whether the microcalcifications seen on ultrasonography are consistent with the pathologic psammoma bodies. We evaluated the relationship between ultrasonographic (US) calcification types and pathologic calcification features, and the consistency between observed pathologic and US calcifications.US calcifications were classified into microcalcification (MC) and nonmicrocalcification (non-MC) types, and pathologic calcifications were classified into 3 types: psammoma bodies, stromal calcifications, and ossifications.Among the 411 nodules that were reviewed by a pathologist, 38.9% (n = 160) had any type of US calcification. The larger the size of pathologic calcification, the more calcification was present in US (psammoma 46.1% < stromal 53.7% < ossification 73.3%). Psammoma bodies occurred in all US MC type. Ossification nodules occurred in nearly all (92.3%) non-MC type. The stromal-only nodules were 36.8% MC-type and 63.2% non-MC type. MC-type had a significantly higher odds ratio than non-MC type for predicting psammoma bodies according to the logistic regression.The presence of MC in ultrasonography was consistent with the presence of psammoma bodies. This study suggests that US identification of MC may be a useful prognostic indicator of PTC aggressiveness.

Calcifications in Thyroid Tumors on Ultrasonography: Calcification Types and Relationship with Histopathological Type

PURPOSE

The purpose of the study is to clarify the prevalence of calcifications within thyroid tumors on ultrasonography as well as the relationship between the calcification and histopathological types.

MATERIALS AND METHODS

Calcifications were classified into 6 (or 8) types according to their shape, size, and region. The prevalence of calcifications and types were investigated in new outpatients and patients who underwent thyroid surgery.

RESULTS

Among 2,902 nodules in 2,678 new outpatients, 747 nodules (26%) had calcifications. The types showed a wide distribution. Among 941 patients with papillary carcinoma (PC), 725 patients (77%) had calcifications, and the types showed a wide distribution. 18 patients with the diffuse sclerosing variant of PC only showed punctate microcalcifications in the parenchyma (100%), 32 patients with the cyst-forming type of PC mostly fragmentary and massive types (100%), and 161 metastatic lymph nodes from PC mostly punctate microcalcifications and fragmentary types (48%). Among 337 patients with follicular carcinoma, 79 patients (23%) had calcifications, and the types were mostly fragmentary, massive, and egg-shell types. Among 41 patients with undifferentiated carcinoma, 33 patients (80%) presented with calcifications, which were mostly the massive and egg-shell types. Among 137 patients with medullary carcinoma, 99 patients (72%) had calcification, and the types showed a wide distribution. None of 173 patients with primary thyroid lymphoma had calcifications (0%).

CONCLUSION

Calcifications on ultrasonography can be one of the characteristic findings and a full understanding of the prevalence of calcifications and types will markedly contribute to the ultrasonic diagnosis of thyroid tumors.

Histopathological investigation of intranodular echogenic foci detected by thyroid ultrasonography

OBJECTIVE

To determine the predictability of sonography for detection of calcifications in thyroid nodules by histopathologic examination and to demonstrate the association between calcification pattern and malignancy.

METHODS

We prospectively evaluated 81 dominant nodules from 81 patients. Thyroid glands were assessed preoperatively with thyroid ultrasonography, and the presence of sonographic calcification was specified as intranodular macro (coarse) and micro calcification. Micro and macro calcification in surgery specimens were specified postoperatively as present or absent in the histopathological evaluation. The correlation between sonographic and histopathologic calcifications and the relationship between malignancy and calcification patterns were determined.

RESULTS

Calcification was detected histopathologically in 66.7% of the sonographically calcified nodules and in 12.8% of the sonographically noncalcified nodules. The sensitivity and specificity of sonography for detecting histopathologic calcification were 84.8 and 70.8%, respectively, while positive and negative predictive values were 66.7 and 87.2%, respectively. The sonographical and histopathological outcomes for detection of macro and micro calcification showed 85 and 50% compatibility, respectively. The difference in malignancy rates between sonographic macro and micro calcified nodules was not significant (p=0.976). Histopathologic detection of calcification showed no significant difference between malignant and benign nodules (p=0.129).

CONCLUSION

Histopathology confirmed a high rate of sonographic macrocalcifications. The micro and macro patterns of sonographic calcification showed no particular association with thyroid malignancy. The preoperative risk of malignancy should be determined in conjunction with other known sonographic risk factors and diagnostic tests.

Diagnostic Performance of SRU and ATA Thyroid Nodule Classification Algorithms as Tested With a 1 Million Virtual Thyroid Nodule Model

PURPOSE

The Society of Radiologists in Ultrasound (SRU 2005) and American Thyroid Association (ATA 2009 and ATA 2015) have published algorithms regarding thyroid nodule management. Kwak et al. and other groups have described models that estimate thyroid nodules' malignancy risk. The aim of our study is to use Kwak's model to evaluate the tradeoffs of both sensitivity and specificity of SRU 2005, ATA 2009 and ATA 2015 management algorithms.

MATERIALS AND METHODS

1,000,000 thyroid nodules were modeled in MATLAB. Ultrasound characteristics were modeled after published data. Malignancy risk was estimated per Kwak's model and assigned as a binary variable. All nodules were then assessed using the published management algorithms. With the malignancy variable as condition positivity and algorithms' recommendation for FNA as test positivity, diagnostic performance was calculated.

RESULTS

Modeled nodule characteristics mimic those of Kwak et al. 12.8% nodules were assigned as malignant (malignancy risk range of 2.0-98%). FNA was recommended for 41% of nodules by SRU 2005, 66% by ATA 2009, and 82% by ATA 2015. Sensitivity and specificity is significantly different (< 0.0001): 49% and 60% for SRU; 81% and 36% for ATA 2009; and 95% and 20% for ATA 2015.

CONCLUSION

SRU 2005, ATA 2009 and ATA 2015 algorithms are used routinely in clinical practice to determine whether thyroid nodule biopsy is indicated. We demonstrate significant differences in these algorithms' diagnostic performance, which result in a compromise between sensitivity and specificity.

Clinical significance of thyroid incidentalomas identified by 18F-FDG PET/CT: correlation of ultrasonograpy findings with cytology results

AIM

The aim of this study was to investigate the clinical importance of incidental focal or diffuse fluorine-18 fluorodeoxyglucose (F-FDG) uptake in the thyroid gland on positron emission tomography (PET)/computed tomography (CT) and to evaluate the additive value of thyroid ultrasonography (US) in defining the malignancy potential of thyroid incidentalomas.

PATIENTS AND METHODS

A total of 1450 patients, who had undergone a PET/CT scan for staging or restaging of various malignancies, were screened retrospectively and 52 (3.6%) patients with focal or diffuse F-FDG uptake in the thyroid gland on PET/CT were enrolled in the study. None of the patients had any history of thyroid diseases. Thyroid US with elastography for a thyroid nodule was performed for all the patients cross-sectionally. Thyroid fine-needle aspiration biopsy (FNAB) was also applied at the same time as the thyroid US to 34 patients with a nodule(s) 10 mm or more in diameter or less than 10 mm, but with malignancy potential ultrasonographically. The cytology results were compared with the thyroid US and F-FDG PET/CT findings.

RESULTS

Although 39 patients had focal (group 1) F-FDG uptake in the thyroid gland, the remaining 13 patients had diffuse (group 2) uptake. In group 1, FNAB was performed in 32 patients. In 10 of 32 (31%) patients, FNAB results were concordant with malignant cytology (seven primary thyroid malignancy and three metastasis to thyroid). In group 2, in one of two patients who had undergone FNAB, malignant cytology (metastasis to thyroid) was detected. Although the difference between the maximum standardized uptake value (SUVmax) of malignant and benign nodules was statistically significant (10.2±8.9 vs. 5.6±3.0, P=0.013), the difference between the nodule sizes was not statistically significant (20.0±7.3 vs. 16.7±7.4, P=0.923). The presence of suspicious US findings and a high elastography score (≥4) were also statistically significant (P<0.001 and P=0.035, respectively). In the receiver-operator characteristic analysis, a 5.3 cut-off SUVmax was calculated with 82% sensitivity and 65% specificity for predicting malignant cytology.

CONCLUSION

Focal F-FDG uptake was associated with a higher prevalence of malignant thyroid nodule compared with diffuse F-FDG uptake. In particular, if a focal thyroid incidentaloma with high SUVmax (>5.5), suspicious US findings, and a high elastography score (≥4) is detected, a pathological diagnosis, either by histology or by cytology examination, should be made, especially when the patient has a long life expectancy.

Calcium role in human carcinogenesis: a comprehensive analysis and critical review of literature

The central role played by calcium ion in biological systems has generated an interest for its potential implication in human malignancies. Thus, lines of research, on possible association of calcium metabolism regulation with tumorigenesis, implying disruptions and/or alterations of known molecular pathways, have been extensively researched in the recent decades. This paper is a critical synthesis of these findings, based on a functional approach of the calcium signaling toolkit. It provides strong support that this ubiquitous divalent cation is involved in cancer initiation, promotion, and progression. Different pathways have been outlined, involving equally different molecular and cellular structures. However, if the association between calcium and cancer can be described as constant, it is not always linear. We have identified several influencing factors among which the most relevant are (i) the changes in local or tissular concentrations of free calcium and (ii) the histological and physiological types of tissue involved. Such versatility at the molecular level may probably account for the conflicting findings reported by the epidemiological literature on calcium dietary intake and the risk to develop certain cancers such as the prostatic or mammary neoplasms. However, it also fuels the hypothesis that behind each cancer, a specific calcium pathway can be evidenced. Identifying such molecular interactions is probably a promising approach for further understanding and treatment options for the disease.

CT-detected solitary thyroid calcification: an important imaging feature for papillary carcinoma

Purpose

To evaluate computed tomography (CT) detection of solitary thyroid calcification for identifying thyroid papillary carcinoma and to determine whether the predictive ability changes when the size increases after enhancement.

Materials and methods

CT scans on all 96 patients with thyroid nodules who underwent both enhanced CT examination of neck and thyroidectomy from 2014 to 2016 in the Shandong Cancer Hospital affiliated to Shandong University were reviewed. The cases without calcification and the cases with peripheral calcification, multiple coarse calcifications, or punctate calcification were excluded. Imaging features, including location and size of the lesions, were reviewed on plain and contrast-enhanced CT. The patients were grouped by histological results. The comparisons were evaluated by using Fisher’s exact test and binary logistic regression.

Results

The study population consisted of 96 patients (74 females, 22 males; mean age 49.8±11.3 years). Papillary thyroid carcinoma was observed in both solitary calcified thyroid nodules (85.4%) and solely coarse calcifications surrounded by low-density focus (58.2%). The difference was significant (P=0.006). Of 64 patients with an amplification of lesions after contrast enhancement, 58 (90.6%) were diagnosed with a malignant lesion. At the same time, of the 32 patients with no increase in size, 10 (31.2%) were diagnosed with carcinoma and 22 (68.8%) with nodular goiter. This difference was significant (P<0.001), and after binary logistic regression, increasing size was an independent risk factor for cancer.

Conclusion

Solitary calcified thyroid nodules detected on CT represent a high risk for papillary thyroid carcinoma, especially when the size of the lesions increases after contrast- enhanced CT.

Is Ultrasonography More Sensitive Than Computed Tomography for Identifying Calcifications in Thyroid Nodules?

OBJECTIVES

The primary objective of this study was to evaluate the difference and agreement between ultrasonography (US) and computed tomography (CT) for identifying calcifications in thyroid nodules.

METHODS

Data from the medical records of 20,248 patients were reviewed for preoperative diagnostic investigations and postoperative pathologic diagnoses. In total, 5247 records were selected for analysis based on the presence of calcifications reported in any of the following 3 modes: US, CT, and pathologic analysis. All 5247 patients underwent US examinations, whereas 3827 underwent cervical CT examinations. All patients had a postoperative pathologic diagnosis serving as a reference. The value of US for identification of calcifications and prediction of malignancy was analyzed on the basis of the entire cohort of 5247 records, whereas that of CT was based on 3827 records. The agreement between US and CT was analyzed on the basis of the 3827 common records.

RESULTS

Of the 5247 patients who underwent US, 4855 (92.5%) were found to have calcifications, whereas of the 3827 patients who underwent CT, 2040 (53.3%) were found to have calcifications (P < .0005). Among the 404 cases with calcifications reported by pathologic analysis, the agreement rate between US and pathologic findings was significantly higher than that between CT and pathologic findings (87.9% versus 81.9%, respectively; P = .018).

CONCLUSIONS

US is more sensitive and accurate than CT for detecting calcifications in thyroid nodules. Hence, US is recommended as the preferred imaging modality for calcification detection in thyroid nodules.

Thyroid calcifications: a pictorial essay

Incidental diagnosis of thyroid nodules is very common on adult neck ultrasonography examination. Thyroid calcifications are encountered in benign thyroid nodules and goiters as well as in thyroid malignancy. Depiction and characterization of such calcifications within a thyroid nodule may be a key element in the thyroid nodule diagnosis algorithm. The goal of this paper is to display typical radio-pathological correlations of various thyroid pathologies of benign and malignant conditions in which the calcification type diagnosis can play a key role in the final diagnosis of the thyroid nodule.

Incidence of malignancy in solitary thyroid nodules

Objectives:

This study aimed to investigate the prevalence and clinical significance of solitary thyroid nodules in patients who underwent thyroid surgery.

Methods:

A retrospective review was performed of the case notes of all adult patients who underwent thyroid surgery from January 2003 to December 2009. All patients with solitary thyroid nodules identified by ultrasonography were included.

Results:

In total, 225 patients underwent thyroid surgery. The prevalence of solitary thyroid nodules was 27.1 per cent (61 out of 225 patients). Seventy-two per cent of patients were women and the mean age at presentation was 52 ± 16 years. In all, 75.4 per cent of solitary nodules had neoplastic pathology and the malignancy rate was 34.4 per cent. The sensitivity and specificity of fine needle aspiration cytology for neoplasm detection were 73.9 per cent and 80.0 per cent, respectively. There was no association between the various ultrasonography parameters and malignancy risk (p > 0.05).

Conclusion:

Solitary thyroid nodules should be investigated thoroughly with a high index of suspicion because there is a high probability (34.0 per cent) of malignancy.

Computerized analysis of calcification of thyroid nodules as visualized by ultrasonography

OBJECTIVE

The purpose of this study is to quantify computerized calcification features from ultrasonography (US) images of thyroid nodules in order to determine the ability to differentiate between malignant and benign thyroid nodules.

METHODS

We designed and implemented a computerized analysis scheme to quantitatively analyze the US features of the calcified thyroid nodules from 99 pathologically determined calcified thyroid nodules. Univariate analysis was used to identify features that were significantly associated with tumor malignancy, and neural-network analysis was performed to classify tumors as benign or malignant. The diagnostic performance of the neural network was evaluated using receiver operating characteristic (ROC) analysis, where in the area under the ROC curve (Az) summarized the diagnostic performance of specific calcification features.

RESULTS

The performance values for each calcification feature were as follows: ratio of calcification distance=0.80, number of calcifications=0.68, skewness=0.82, and maximum intensity=0.75. The combined value of the four features was 0.84.With a threshold of 0.64, the Az value of calcification features was 0.83 with a sensitivity of 83.0%, specificity of 82.4%, and accuracy of 82.8%.

CONCLUSIONS

These results support the clinical feasibility of using computerized analysis of calcification features from thyroid US for differentiating between malignant and benign nodules.

Thyroid ultrasound features and risk of carcinoma: a systematic review and meta-analysis of observational studies

BACKGROUND

Thyroid nodules are a common finding in the general population, and their detection is increasing with the widespread use of ultrasound (US). Thyroid cancer is found in 5-15% of cases depending on sex, age, and exposure to other risk factors. Some US parameters have been associated with increased risk of malignancy. However, no characteristic seems sufficiently reliable in isolation to diagnose malignancy. The objective of this meta-analysis was to evaluate the diagnostic performance of US features for thyroid malignancy in patients with unselected thyroid nodules and nodules with indeterminate fine-needle aspiration (FNA) cytology.

METHODS

Electronic databases were reviewed for studies published prior to July 2012 that evaluated US features of thyroid nodules and reported postoperative histopathologic diagnosis. A manual search of references of review and key articles, and previous meta-analyses was also performed. A separate meta-analysis was performed including only nodules with indeterminate cytology. Analyzed features were solid structure, hypoechogenicity, irregular margins, absence of halo, microcalcifications, central vascularization, solitary nodule, heterogeneity, taller than wide shape, and absence of elasticity.

RESULTS

Fifty-two observational studies (12,786 nodules) were included. Nine studies included nodules with indeterminate cytology as a separate category, comprising 1851 nodules. In unselected nodules, all US features were significantly associated with malignancy with an odds ratio varying from 1.78 to 35.7, and microcalcifications, irregular margins, and a taller than wide shape had high specificities (Sp; 87.8%, 83.1%, 96.6%) and positive likelihood ratios (LHR; 3.26, 2.99, 8.07). Absence of elasticity was the single feature with the best diagnostic performance (sensitivity 87.9%, Sp 86.2%, and positive LHR 6.39). The presence of central vascularization was the most specific US feature in nodules with indeterminate cytology (Sp 96% and positive LHR 2.13).

CONCLUSIONS

US features in isolation do not provide reliable information to select nodules that should have a FNA performed. A combination of US characteristics with higher likelihood ratios and consequently with higher post-test probabilities of malignancy-microcalcifications, or a taller than wide shape, or irregular margins, or absence of elasticity-will probably identify nodules with an increased risk for malignancy. Further studies are required to standardize elastography techniques and evaluate outcomes, especially in nodules with an indeterminate cytology.

Elastography can effectively decrease the number of fine-needle aspiration biopsies in patients with calcified thyroid nodules

When calcification, frequently found in both benign and malignant nodules, is present in thyroid nodules, non-invasive differentiation with ultrasound becomes challenging. The goal of this study was to evaluate the utility of elastography in differentiating calcified thyroid nodules. Consecutive patients (165 patients with 196 nodules) referred for fine-needle aspiration who had undergone both ultrasound elastography and B-mode examinations were analyzed retrospectively. Calcification was present in 45 benign and 20 malignant nodules. On 65 calcified nodules, elastography had 95% sensitivity, 51.1% specificity, 46.3% positive predictive value and 95.8% negative predictive value in detecting malignancy. Twenty-three of 45 benign calcified nodules were correctly diagnosed with elastography compared with 4 of 45 by B-mode ultrasound. Although it is difficult to differentiate benign and malignant calcified thyroid nodules solely with B-mode ultrasound, elastography has the potential to reduce the number of fine-needle aspiration biopsies performed on calcified nodules.

Thyroid metastasis from breast cancer presenting with diffuse microcalcifications on sonography: a case report

Microcalcifications are frequently associated with papillary thyroid cancers. Metastatic nodules from extrathyroid malignancies may mimic primary thyroid neoplasm on sonography, but do not present with microcalcifications. We report the case of a 45-year-old woman with a history of invasive ductal carcinomas of bilateral breasts, status post surgery and neoadjuvant chemotherapy. Four years after surgery, thyroid sonography revealed diffuse microcalcifications without nodular component. Core needle biopsy confirmed thyroid metastasis from primary breast cancer.

Ultrasonographic findings relating to lymph node metastasis in single micropapillary thyroid cancer

Background

In thyroid cancer, preoperative ultrasonography (US) is performed to detect the primary tumor and lymph node metastasis (LNM), which are related to prognosis. This study examined the relationships between specific US findings and LNM in micropapillary thyroid cancer (MPTC).

Methods

Data on 220 patients with solitary MPTC who underwent total thyroidectomy and neck dissection between 2008 and 2009 were evaluated retrospectively. We classified the US findings according to the nature, shape, echogenicity, extent, margin, and calcification of the primary tumor and evaluated the correlations between these findings and those of LNM.

Results

Hypoechogenicity (odds ratio = 2.331, P = 0.025) and marked hypoechogenicity (OR = 4.032, P = 0.016) of MPTC were risk factors for central LNM. All of the patients with lateral cervical LNM showed hypoechogenicity or marked hypoechogenicity. Hypoechogenicity (odds ratio = 5.349, P = 0.047) and other types of calcification (odds ratio = 2.495, P = 0.010) were significant risk factors for lateral cervical LNM.

Conclusions

Specific sonographic findings (hypoechogenicity or marked hypoechogenicity, and calcification) suggest LNM.

What is the Role of Diffusion Weigh Magnetic Resonance Imaging in Evaluation of Thyroid Nodules?

This study aimed to compare ultrasonography (US), contrast-enhanced computed tomography (CCT) of the neck, and diffusion-weigh magnetic resonance imaging (DW-MRI) in differentiating between benign and malignant nodules while approaching to thyroid nodules, and to estimate sensitivity and specificity of these methods. On thyroid US, echogenicity, calcification, presence/absence of halo, nodule size being larger/smaller than 20 mm, and nodule nature (cystic/solid nature) were evaluated. Findings on CCT of the neck were grouped according to the heterogeneity/homogeneity, presence/absence of enhancement, and intensity. On DW-MRI, diffusion restriction was evaluated. The findings of these tests were compared with postoperative histopathological findings, and specificity and sensitivity of the tests in differentiating malignant and benign nodules were assessed. The study included 38 patients (34 females, 4 males). The sensitivity and specificity of DW-MRI were 20 and 75 %, respectively. Presence of a >20 mm nodule in thyroid US had the highest sensitivity, whereas thyroid fine-needle aspiration biopsy (FNAB) had the highest specificity in detecting malignancy. The sensitivities and specificities of CCT of the neck and DW-MRI appeared relatively low. Evaluation of thyroid US findings together with thyroid FNAB findings provided high specificity and sensitivity and yielded better results than findings of CCT of the neck and DW-MRI.

The accuracy of thyroid nodule ultrasound to predict thyroid cancer: systematic review and meta-analysis

CONTEXT

Significant uncertainty remains surrounding the diagnostic accuracy of sonographic features used to predict the malignant potential of thyroid nodules.

OBJECTIVE

The objective of the study was to summarize the available literature related to the accuracy of thyroid nodule ultrasound (US) in the prediction of thyroid cancer.

METHODS

We searched multiple databases and reference lists for cohort studies that enrolled adults with thyroid nodules with reported diagnostic measures of sonography. A total of 14 relevant US features were analyzed.

RESULTS

We included 31 studies between 1985 and 2012 (number of nodules studied 18,288; average size 15 mm). The frequency of thyroid cancer was 20%. The most common type of cancer was papillary thyroid cancer (84%). The US nodule features with the highest diagnostic odds ratio for malignancy was being taller than wider [11.14 (95% confidence interval 6.6-18.9)]. Conversely, the US nodule features with the highest diagnostic odds ratio for benign nodules was spongiform appearance [12 (95% confidence interval 0.61-234.3)]. Heterogeneity across studies was substantial. Estimates of accuracy depended on the experience of the physician interpreting the US, the type of cancer and nodule (indeterminate), and type of reference standard. In a threshold model, spongiform appearance and cystic nodules were the only two features that, if present, could have avoided the use of fine-needle aspiration biopsy.

CONCLUSIONS

Low- to moderate-quality evidence suggests that individual ultrasound features are not accurate predictors of thyroid cancer. Two features, cystic content and spongiform appearance, however, might predict benign nodules, but this has limited applicability to clinical practice due to their infrequent occurrence.

Diagnostic Value of Ultrasound-detected Calcification in Thyroid Nodules

Introduction: This study analyses the diagnostic value of ultrasonography (US) detection for calcification in thyroid nodules. Materials and Methods: We analysed the preoperative US findings and clinical characteristics of 577 malignant and 3434 benign thyroid patients who underwent surgery in our hospital. Results: The malignant rate in patients with microcalcification hyperechoic and tiny calcification foci ≤2 mm in diameter was significantly higher than the non-calcification and other calcification group (P <0.001). The malignant rate in single calcification nodule was significantly higher than that in multiple nodule group (P <0.01). Most of the patients (37/39) with lymph node calcification were malignant. The malignant rate of calcification and microcalcification was significantly higher in patients <45 years old than in older patients (P <0.05). Conclusion: Compared with other calcifications, microcalcification should be a better predictor of thyroid carcinoma. Malignancy should be highly suspected in patients with single calcification nodule, especially with lymph node calcification. Patients younger than 45 years of age with calcification or microcalcification have a greater risk for thyroid carcinoma. Key words: Age, Single nodule, Thyroid carcinoma, Ultrasonography

Relationship between the Prevalence of Thyroid Nodules and Metabolic Syndrome in the Iodine-Adequate Area of Hangzhou, China: A Cross-Sectional and Cohort Study

Objective. The association between thyroid nodule (TN) prevalence and metabolic syndrome (MetS) has only rarely been examined in iodine-adequate areas and needs further clarification. We investigated correlations between MetS and TN prevalence in the iodine-adequate area of Hangzhou, China. Material and Method. A cross-sectional study that screened and recruited individuals for cohort research 3 years later. The 13522 subjects (8926 men, 4596 women) were screened in 2009 for all MetS components, thyroid ultrasound (US), and thyroid function. Cohort research recruited 1610 subjects who were screened in both 2009 and 2012, of whom 1061 underwent follow-up research. Results. The prevalence of TN was higher in the MetS (+) group than in the MetS (-) group (χ (2) = 69.63, P < 0.001) and higher in women than in men (χ (2) = 11.65, P = 0.001). Waist circumference (WC) was positively related to the prevalence of TN (OR = 1.022, P < 0.001). Individuals with greater WC in 2009 were more likely to suffer from TN in 2012 (RR = 1.434, P = 0.024). Elevated triglyceride level was a risk factor for developing new TN (RR = 1.001, P = 0.035). Conclusion. Both greater WC and elevated triglycerides are risk factors for new TN in this iodine-adequate area in China.

Impact of nodular size on the predictive values of gray-scale, color-Doppler ultrasound, and sonoelastography for assessment of thyroid nodules

OBJECTIVE

To define the roles of gray-scale, color-Doppler ultrasound, and sonoelastography for the assessment of thyroid nodule to determine whether nodule size affects the differential diagnosis of benign and malignant.

METHODS

A total of 243 consecutive subjects (214 women, 29 men) with 329 thyroid nodules were examined by gray-scale, color-Doppler ultrasound, and sonoelastography in this prospective study. All patients underwent surgery and the final diagnosis was obtained from histopathological examination.

RESULTS

Three hundred and twenty-nine nodules (208 benign, 121 malignant) were divided into small (SNs, 5-10 mm, n=137) and large (LNs, >10 mm, n=192) nodules. Microcalcifications were more frequent in malignant LNs than in malignant SNs, but showed no significant difference between benign LNs and SNs. Poorly-circumscribed margins were not significantly different between malignant SNs and LNs, but were less frequent in benign LNs than in benign SNs. Among all nodules, marked intranodular vascularity was more frequent in LNs than in SNs. By comparison, shape ratio of anteroposterior to transverse dimensions (A/T) ≥ 1 was less frequent in LNs than in SNs. Otherwise, among all nodules, marked hypoechogenicity and elasticity score of 4-6 showed no significant difference between LNs and SNs.

CONCLUSIONS

The predictive values of microcalcifications, nodular margins, A/T ratio, and marked intranodular vascularity depend on nodule size, but the predictive values of echogenicity and elastography do not.

Relationship between patterns of calcification in thyroid nodules and histopathologic findings

Various patterns of calcification have been detected in benign and malignant thyroid nodules on ultrasonography (US). Microcalcification has been found to be highly associated with papillary thyroid carcinoma. However, other patterns of calcification have unclear clinical significance. The aim of this study was to evaluate which pattern of calcification could be predictive of malignancy. A total of 1,431 thyroid nodules of 1,078 patients who received preoperative ultrasound examinations and subsequently underwent thyroidectomy were retrospectively reviewed. The types of calcification were defined as follows: microcalcification, annular-like peripheral calcification, crescent-like peripheral calcification, intranodular coarse calcification, and calcified spot. Of these 1,431 nodules, 1,305 (91.1%) were thyroid carcinomas and 126 (8.9%) were benign nodules. Calcifications were detected in 38.6% (552/1,431) of all nodules. Calcifications were found in 40.2% (524/1,305) of malignant nodules and 22.2% (28/126) of benign nodules. Of the 524 malignant nodules with calcification, microcalcification was the most common pattern, occurring in 42.9% (225/524), and annular type was the least common pattern, occurring in 5.9% (31/524). Among the calcification types, only microcalcification and intranodular had a significant association with malignancy (p = 0.001, 0.035), with OR values of 3.5 (95% CI, 1.6-7.7) and 2.4 (95% CI, 1.1-5.6). Though using the patterns of calcification alone for predicting malignancy had limitation, microcalcification and intranodular calcification were significantly associated with malignancy.

Ultrasound findings of papillary thyroid microcarcinoma: a review of 113 consecutive cases with histopathologic correlation

Papillary thyroid microcarcinoma (PTMC) is a malignant thyroid tumor of less than 1 cm in size. Ultrasound (US) is the preferred imaging modality for PTMC. This study retrospectively evaluated the US results from 113 consecutive cases of PTMC with 127 nodules and correlated the results with the histopathologic findings. The results showed none of the PTMC nodules had a cystic element. Half of the PTMC nodules had a well-defined boundary and the remaining half had an ill-defined boundary. A percent (6.3%) of the nodules had a halo sign. Microcalcification was present in approximately half of the PTMC nodules. The cancerous tissue with a papillary structure was hypoechogenic and the amount of fibrous stroma determined whether the nodule echogenicity was heterogeneous or homogeneous. Heterogeneous echogenicity was associated with a fibrous stroma proportion of >20%. Only PTMC nodules with predominantly follicular structures containing a large proportion of colloid demonstrated isoechogenicity. Well-defined boundaries on US were associated with well-defined histologic margins, with or without the presence of an intact fibrous pseudo-capsule. A halo sign with a well-defined boundary detected by US was associated with the presence of an intact fibrous pseudo-capsule. Half of the PTMC nodules with ill-defined boundaries exhibited infiltration into the surrounding thyroid tissue, while the remaining half of the PTMC nodules with ill-defined boundaries on US presented irregular nodule margins by histology, rather than nodule infiltration. Psammoma bodies detected at a frequency ≥5 per ×200 microscopic field of view were detectable on US as microcalcifications.

Correlation between Thyroid Nodule Calcification Morphology on Ultrasound and Thyroid Carcinoma

OBJECTIVE: This study investigated the detection of thyroid nodule calcifications on ultrasound and their relationship to thyroid carcinoma. METHODS: Microcalcifications (≤ 2 mm) and macrocalcifications (> 2 mm) on preoperative ultrasound examination of thyroid and lymph nodes were compared with postoperative pathological diagnoses in 4186 patients undergoing thyroid surgery. RESULTS: Higher incidences of micro- and macrocalcifications were found in patients with thyroid carcinoma than in those with benign disease. The incidence of malignant disease was significantly higher in patients with microcalcifications than those with macrocalcifications, suggesting that the presence of microcalcifications is a better predictor of malignant thyroid carcinoma than other calcification types. The specificity of microcalcifications for a diagnosis of malignant thyroid carcinoma was 96.5%. Microcalcifications were significantly more frequent in patients aged ≤ 45 years, but there was no difference between genders. The incidence of malignancy was significantly higher in patients with single nodule calcifications than in those with multiple nodule calcifications. Lymph node calcifications were seen in 12 patients, all of whom had papillary carcinoma. CONCLUSIONS: Thyroid microcalcifications are strongly associated with thyroid carcinoma, especially micropapillary carcinoma. When cervical lymph node calcification is present, immediate surgery is required.

An elevated level of TSH might be predictive of differentiated thyroid cancer

Suppression therapy of thyreostimulin (TSH) using thyroid hormones improves survival of subjects operated for differentiated thyroid cancer. The TSH level might be different depending on the type of nodule. The objective of this study was to compare retrospectively the TSH level between two groups of subjects who underwent total thyroidectomy for a nodule, matched on sex, ethnicity, age and biological method of TSH measurement, one whose final histology was benign and one malignant. There was no significant difference between the two groups in terms of age, sex, family history of thyroid disease or thyroid autoimmunity. The subjects, whose final histology was malignant, had a mean TSH level significantly higher than subjects with benign disease (1.55 mU/l versus 0.96 mU/l, P=0.003). Cancer risk was greater when the TSH was in the upper tertile of normal range. There was no correlation between the risk of thyroid cancer and age, sex, family history of thyroid disease, or menopausal status. The relative risk of having thyroid carcinoma was higher when the margins of nodules were blurred or in the presence of microcalcifications. These data confirm a trend toward baseline values of TSH higher in subjects with a thyroid-differentiated cancer. However, we could not define a preoperative threshold that would reliably determine the malignant or benign nature of the nodule.

Sonographic Findings of Medullary Thyroid Carcinoma Leading to Diagnosis of Multiple Endocrine Neoplasia Type 2a during Pregnancy

Multiple endocrine neoplasia (MEN) type 2a (Sipple's syndrome) is characterized by medullary thyroid carcinoma and pheochromocytoma, and in a smaller percentage of cases, multiglandular parathyroid hyperplasia. This autosomal-dominant syndrome is due to a mutation in the rearranged during transfection (RET) proto-oncogene located on chromosome 10cen-10q11.2 and rarely complicates pregnancy. We present an unusual case in a patient with an enlarged thyroid with sonographic findings characteristic of thyroid cancer, which led to diagnosis and subsequent management of RET proto-oncogene-positive MEN type 2a complicating pregnancy.

Differentiation between benign and malignant solid thyroid nodules using an US classification system

Objective

To evaluate the diagnostic accuracy of a new ultrasound (US) classification system for differentiating between benign and malignant solid thyroid nodules.

Materials and Methods

In this study, we enrolled 191 consecutive patients who received real-time US and subsequent US diagnoses for solid thyroid nodules, and underwent US-guided fine-needle aspiration. Each thyroid nodule was prospectively classified into 1 of 5 diagnostic categories by real-time US: "malignant," "suspicious for malignancy," "borderline," "probably benign," and "benign". We evaluated the diagnostic accuracy of thyroid US and the cut-off US criteria by comparing the US diagnoses of thyroid nodules with cytopathologic results.

Results

Of the 191 solid nodules, 103 were subjected to thyroid surgery. US categories for these 191 nodules were malignant (n = 52), suspicious for malignancy (n = 16), borderline (n = 23), probably benign (n = 18), and benign (n = 82). A receiver-operating characteristic curve analysis revealed that the US diagnosis for solid thyroid nodules using the 5-category US classification system was very good. The sensitivity, specificity, positive and negative predictive values, and accuracy of US diagnosis were 86%, 95%, 91%, 92%, and 92%, respectively, when benign, probably benign, and borderline categories were collectively classified as benign (negative).

Conclusion

The diagnostic accuracy of thyroid US for solid thyroid nodules is high when the above-mentioned US classification system is applied.

Thyroid ultrasonography. Part 2: nodules

This article reviews common ultrasonographic patterns identified in both benign and malignant thyroid nodules. Categorizing nodules into benign and malignant patterns may be helpful to decide if ultrasound-guided fine-needle aspiration (FNA) should be performed. In addition, the FNA biopsy guidelines issued by major organizations are reviewed.

Clinical value of using ultrasound to assess calcification patterns in thyroid nodules

BACKGROUND

Differentiating between benign and malignant thyroid nodules is important for providing appropriate treatment. In the present study we examined the clinical usefulness of ultrasound in examining calcification patterns in thyroid nodules, and thus predict malignancy.

METHODS

The records of 1,498 Chinese patients who underwent thyroidectomy for nodular thyroid disease were retrospectively examined. All patients underwent thyroid ultrasound within 1 month before surgery. Calcification patterns in thyroid nodules were examined, and tissue samples were analyzed to determine a pathological diagnosis. Calcifications were defined as macrocalcifications, microcalcifications, rim calcifications, or isolated calcifications.

RESULTS

A total of 2,122 thyroid nodules were examined, and 259 nodules (12.2%) were found to be malignant. Papillary carcinoma accounted for 85.3% of all malignancies. The majority of benign lesions were nodular goiters. Calcification was detected in 49.6% of malignant nodules and 15.7% of benign nodules. Microcalcifications were significantly more common in malignant nodules as compared to benign nodules (33.7 vs. 6.4%; P < 0.001). The sensitivity and specificity of microcalcifications for predicting malignancy were 33.7 and 93.6%, respectively, while the positive and negative likelihood ratios were 42.0 and 91.1%, respectively.

CONCLUSIONS

Calcifications, as detected by ultrasonography, are evident in benign and malignant thyroid nodules. Although microcalcifications are more common in malignant thyroid nodules than in benign ones, the clinical value of using the presence of microcalcifications alone for predicting malignancy is limited.

Value of specimen radiographs in diagnosing multifocality of thyroid cancer

BACKGROUND

Specimen radiography has been used widely to evaluate the complete excision of calcified breast lesions but has not been evaluated for thyroid cancer.

METHODS

Specimen radiographs were evaluated retrospectively to identify additional cancers that were demonstrated only as calcifications. Receiver operating characteristic curve analysis was performed to compare the combination of specimen radiography and ultrasonography versus ultrasonography alone for detecting multifocality.

RESULTS

Some 122 thyroid cancer specimens were obtained from 122 patients between January and April 2008. Specimen radiography detected 27 cancers (18.5 per cent) not detected by ultrasonography. Diagnoses were changed after evaluation of specimen radiographs in three of these patients. The area under the curve of the combination of specimen radiography and ultrasonography was significantly higher than that of ultrasonography alone (P = 0.005).

CONCLUSION

Specimen radiography is a potentially useful tool for diagnosing cancer type and predicting the extent of thyroid cancer.

Sonography of thyroid nodules with peripheral calcifications

PURPOSE

This study was designed to assess the role of sonography (US) in the differentiation of benign from malignant thyroid nodules with peripheral calcifications.

METHODS

Sixty-four thyroid nodules with peripheral calcifications that were detected on US were included in the study. Nineteen nodules (30%) were benign, and 45 nodules (70%) were malignant. We retrospectively compared the US findings of the benign and malignant nodules, including interruption, thickening (>or=0.5 mm and over more than 50% of the circumference) of calcifications, internal echogenicity, margin, and presence of cystic change, size, and shape. Univariate and multivariate logistic regression analyses were performed.

RESULTS

Interruption of peripheral calcifications was more common in malignant nodules (84%) than in benign nodules (53%) (OR, 7.9; 95% CI, 1.3-48.4; p < 0.05). Thickening of the peripheral calcification was seen more frequently in malignant nodules (64%) than in benign nodules (11%) (OR, 14.7; 95% CI, 1.8-117.5; p < 0.05). For internal echogenicity, malignant nodules (58%) were more often hypoechoic than benign nodules (OR, 23.6; 95% CI, 2.2-256.3; p < 0.01). The mean tumor size was 1.1 cm for malignant nodules and 1.2 cm for benign nodules (p > 0.05). There were no significant differences for the presence or absence of cystic change, size, shape, and margin between malignant and benign nodules.

CONCLUSION

Interruption and thickening of peripheral calcifications and decreased internal echogenicity of a thyroid nodule with peripheral calcifications are in favor of malignancy.

Risk factors for well-differentiated thyroid carcinoma in patients with thyroid nodular disease

OBJECTIVES

Evaluate current accepted risk factors for well-differentiated thyroid carcinoma, and develop a predictive model to determine one's risk of malignancy given a thyroid nodule.

STUDY DESIGN

Retrospective analysis of 600 patients.

SUBJECTS AND METHODS

Patients with benign thyroid nodular disease and with well-differentiated thyroid cancer were randomly selected. Patient, clinical, and investigational data were compared by means of univariate and multivariate regression analyses.

RESULTS

Age, regional lymphadenopathy, ipsilateral vocal cord palsy, solid and/or calcified nodules, and an aspiration biopsy being malignant or suspicious predicted for cancer (P < 0.05). Regional lymphadenopathy and vocal cord palsy are perfect predictors of malignancy. Multivariate analysis indicated age, solid and/or calcified nodules, and all fine-needle aspiration biopsy results to be significant in assessing risk (P < 0.05).

CONCLUSION

Taking individual risk factors in isolation is not always reliable. Using a predictive model, one can anticipate a patient's risk of malignancy when the diagnosis is unclear.

Impact of preoperative thyroid ultrasonography on the surgical management of primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (PHPT) with coexisting thyroid disease has been considered a contraindication to minimally invasive parathyroidectomy (MIP). This study assessed the impact of thyroid ultrasonography and guided fine-needle aspiration (FNA) biopsy with cytological review of the aspiration in distinguishing patients eligible for MIP from those requiring open parathyroidectomy with thyroid surgery.

METHODS

The records of 194 consecutive patients who had minimally invasive or open parathyroidectomy for sporadic PHPT were reviewed retrospectively. Thyroid ultrasonographic findings and FNA results were compared with surgical and pathology records.

RESULTS

A total of 163 patients (84.0 per cent) were eligible for MIP based on ultrasonographic findings with or without FNA results. Ultrasonography detected concurrent thyroid disease in 163 patients (84.0 per cent). Thirty-nine (23.9 per cent) underwent FNA, of whom 16 had benign findings and were eligible for MIP; the remaining 23 had suspicious FNA results and had open parathyroidectomy combined with thyroid surgery. Postoperative thyroid histopathology confirmed malignancy in nine patients, eight of whom had disease detected ultrasonographically. Micronodular thyroid disease (less than 1 cm) accounted for four of nine malignancies.

CONCLUSION

Most patients with PHPT are eligible for MIP. Experienced ultrasonographers can diagnose coexisting micronodular and macronodular thyroid disease, and identify patients eligible for MIP.

Differentiation of thyroid nodules with macrocalcifications: role of suspicious sonographic findings

OBJECTIVE

The purpose of this study was to determine which types of macrocalcifications are associated with thyroid carcinoma and to assess the role of other suspicious sonographic findings in thyroid nodules with macrocalcifications.

METHODS

Our Institutional Review Board approved this retrospective study, and informed consent was not required. We reviewed sonographic findings of thyroid nodules in 722 patients that underwent thyroid surgery in our institution between March 2006 and August 2006. Sonographic results were grouped into 3 types of macrocalcifications. Each lesion was evaluated on the basis of other suspicious sonographic criteria, including marked hypoechogenicity, irregular or microlobulated margins, and a taller-than-wide shape. Sensitivity and specificity based on sonographic criteria were calculated and compared among the subtypes of macrocalcifications.

RESULTS

One hundred seventy-four nodules showed macrocalcifications; 116 were malignant, and 58 were benign. Among the macrocalcification categories, solitary calcifications were more common in benign thyroid lesions, whereas coarse calcifications not otherwise specified were more common in malignant lesions (P < .05). Although the risk of malignancy was 17.2% in cases with no suspicious sonographic findings, the risk of malignancy was up to 82.8% in cases with at least 1 of the sonographic criteria (P < .05). On the basis of the suspicious sonographic criteria, the overall sensitivity was 82.8%. There was no statistically significant difference in sensitivity among the macrocalcification subtypes (P > .05).

CONCLUSIONS

Suspicious sonographic features such as marked hypoechogenicity, irregular or microlobulated margins, and a taller-than-wide shape can play important roles in differentiating benign and malignant thyroid nodules with macrocalcifications.

[Usefulness of ultrasound in the diagnosis and management of well-differentiated thyroid carcinoma]

Thyroid nodules are found in the vast majority of the population, but only 5 to 10% are malignant. Ultrasonography of the thyroid, by virtue of being a straightforward, non-invasive method presenting strong correlation with macroscopic aspects of the thyroid gland, is being increasingly used to identify nodules that present a higher risk of malignancy. The presence of certain ultrasonographic characteristics such as hypoechogenicity, microcalcifications, irregular contours and central vascularization on Doppler, increase the risk of the lesion being malignant. Conversely, nodules presenting benign ultrasonographic characteristics such as hyperechogenicity and a mixed sponge-like aspect, and a concordant cytology, have a negative predictive value of 96.6%. It is, thus, important to examine all nodular lesions and to identify suspicious lesions that need biopsy, especially in multinodular glands. Ultrasonography is also highly sensitive in the identification of suspicious cervical lymph nodes during the follow-up of patients with thyroid carcinoma, even when PCI is negative and serum thyroglobulin (Tg) levels are undetectable. Tg measurement in the needle wash-out content is recommended as this has proven to be more sensitive than cytology in the diagnosis of cervical metastasis, especially where there is liquid content, and it is not affected by the presence of anti-Tg antibodies.