Should we use ultrasound features associated with papillary thyroid cancer in diagnosing medullary thyroid cancer?

The impact of Hashimoto's thyroiditis on the clinical outcome of papillary thyroid cancer after radioactive iodine therapy: a propensity score matching study

OBJECTIVE

The potential association between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC) has been studied from different perspectives for many years. This study was aimed to evaluate the impact of HT on the clinical outcomes of PTC patients after radioactive iodine (RAI) therapy.

MATERIAL AND METHODS

We conducted a retrospective study on consecutive patients with PTC who underwent RAI therapy from April 2017 to May 2020. The diagnosis of HT was based on pathological examination, and patients were divided into the HT and non-HT group. Distributions of age, gender, ultrasound features, papillary variants, extrathyroidal extension, and other histopathological characteristics were observed. Propensity score matching (PSM) was used to compare the clinical features and outcomes between the two groups at 1 and 3-year follow-up.

RESULTS

In total, 782 patients with PTC were enrolled (570 women, 212 men). HT was presented in 130 (16.6%) patients, and was associated with younger age, smaller primary tumors, less extrathyroidal extension, and less lymph node metastasis at presentation. On review of the images, only calcification and blood flow distribution were significantly different among the US features (P < 0.05). At the end of follow-up (three years), the responses to RAI therapy were significantly different between the two groups (ER: 76.9% vs 64.9%; IDR:11.5% vs 17.2%; BIR: 4.6% vs 10.7%; SIR: 6.9% vs 7.2%, P = 0.03). Patients with HT had less frequently evidence of disease (11.6% vs 17.9%). When compared with the matched groups, 123 pairs of patients were successfully matched, PTC patients with HT were found to have a better response to RAI therapy.

CONCLUSIONS

PTC patients with HT had less aggressive characteristics at presentation. Importantly, the presence of HT not only had a significant association with the outcome, but was also protective from the risk of recurrence.

The impact of preoperative calcitonin screening on the prognosis of patients with medullary thyroid cancer: a retrospective multicenter cohort study

PURPOSE

There is still controversy in different guidelines regarding the necessity of routine preoperative calcitonin (Ctn) testing in medullary thyroid cancer (MTC). The level of preoperative Ctn may influence the extent of surgery.

METHODS

This retrospective multicenter cohort study involved 149 MTC patients from 6 centers between 2013 to 2023. Clinical characteristics, surgical procedure and clinical outcomes were compared between Ctn-screened and Non-screened group. Kaplan-Meier method was used to estimate recurrence-free survival (RFS) and overall survival (OS).

RESULTS

In total, 127 MTC patients with preoperative Ctn screening and 22 MTC patients without screening were analyzed. MTC patients with preoperative Ctn screening underwent more radical surgical procedures including total thyroidectomy and lymph node dissection, compared to those without screening (84.3% vs. 68.2% and 91.3% vs. 72.7%, respectively). The rate of recurrence and death were lower in the Ctn-screened group (16.1% vs. 36.4%, 0.8% vs. 18.2%, respectively). The survival curve showed a significantly better overall survival in Ctn-screened group than Non-screened group (HR:17.932, 95% CI 1.888-170.294, p-value = 0.001), while no significant difference was observed of RFS between two groups (HR:1.6, 95% CI 0.645-3.966, p-value = 0.307).

CONCLUSION

Preoperative Ctn screening can prompt surgeons choosing more radical initial surgical treatment for MTC patients, potentially leading to better long-term outcomes. Further evaluation of the cost-effectiveness of routine Ctn screening in thyroid nodule patients is warranted.

Using preoperative ultrasound vascularity characteristics to estimate medullary thyroid cancer

BACKGROUND

The early diagnosis of medullary thyroid carcinoma (MTC) is still a challenge in clinical practice. Based on ultrasound features, many MTC cases without suspicious characteristics are not categorized as high risk for malignancy. This study was designed to comprehensively investigate the ultrasonic features of MTC on ultrasound and help identify thyroid nodules with a high risk of MTC.

METHODS

Between 2017 and 2023, we retrospectively reviewed 116 consecutive thyroid nodules with a histologic diagnosis of MTC who had undergone preoperative ultrasound examination. According to the ultrasonic criteria for risk classification, nodules were classified as "ultrasound-high suspicious" (h-MTC) and "ultrasound-low suspicious" (l-MTC). Using the same database, a tumour size- and risk evaluation-matched control group comprising 62 lesions was randomly selected to compare the vascularity features of l-MTC disease.

RESULTS

We identified 85 h-MTC nodules (73.3%) and 31 l-MTC nodules (26.7%). For patients with l-MTC disease, 22/31 (71.0%) of the lesions were followed up for a period before fine needle aspiration (FNA) or surgery. We observed more penetrating branching vascularity in the l-MTC group than in the benign nodule group (23/31, 74.2% vs. 5/59, 4.8%, P < 0.001). We also showed that more CHAMMAS IV patterns (central blood flow greater than perinodular flow) (87.1% vs. 32.3%, P < 0.001)) and CHEN IV patterns (penetrating vascularity) (100% vs. 25.8%, P < 0.001) were found in l-MTC than benign nodules.

CONCLUSIONS

Vascularity features can help differentiate l-MTC from benign nodules; moreover, we report a novel sonographic vascularity pattern of l-MTC disease, penetrating branching vascularity. The utilization of vascularity features will help to identify MTC among nodules with low-intermediate suspicion by ultrasound risk classification to ensure appropriate clinical management.

Medullary thyroid cancer - An update

Medullary thyroid cancer (MTC) is a rare neuroendocrine disease, encompassing about 5% of all thyroid cancers. Due to its peculiar features, this rare tumour offers unique possibilities for translational research studies. It arises from neuroendocrine parafollicular cells in an endocrine organ, and appears as a nodule apparently indistinguishable from thyroid nodules. It has a very peculiar progression with micro metastases difficult to identify, often-remaining stable during years and suddenly undergoing a rapid and unrestrainable progression. Moreover, MTC is one of the neoplasms with the best genetic characterization either in its sporadic or familial form, providing a valuable background to test targeted drugs. In the era of precision medicine, this review aims to give an update on the diagnostic tools, the therapeutic options for advanced MTC, and the most promising opportunities for a personalized follow up.

Sonographic risk factors of aggressive behaviors in medullary thyroid carcinomas

OBJECTIVE

To identify the clinical and sonographic risk factors for aggressive behavior of Medullary Thyroid Carcinomas (MTCs).

MATERIAL AND METHODS

This is a retrospective analysis. The informed consents were waived. Totally, 127 patients were selected from the database. Two radiologists were invited to review the clinical records and ultrasonic images and scored all the cases according to ACR TI-RADS, retrospectively. Kappa test was used to evaluate the consistency between the two reviewers. Logistic regression analysis was carried to identify the risk factors for aggressive behaviors of MTCs. Comparison of survival proportions between different groups were calculated by Kaplan-Meier method and log-rank test.

RESULTS

Female patients with MTCs were more commonly seen than male (1.7:1), male sex was a risk factor for both metastasis (OR: 4.471, P = 0.001) and perithyroidal invasion (OR = 4.674, P = 0.004). Consistency between the two reviewers were quite high (K value, 0.797-0.988). On sonograms, typical MTCs manifest as hypoechoic (96.9%) solid nodules (94.5%). Sex of patients (P = 0.001), margin (P = 0.003) and focality (P = 0.01) of the nodule were independent risk factors for metastasis, whereas sex of the patients (P = 0.004) and margin (P = 0.000) were independent risk factors for perithyroidal invasion. By Kaplan-Meier analysis, survival proportions different between groups with/without perithyroidal extension (P = 0.000) but not between groups with/without metastasis (P = 0.473).

CONCLUSION

High frequency ultrasound and TI-RADS were effective methods for preoperative diagnosis of MTC. Sex of the patients and margin of the nodule are common risk factors for both metastasis and perithyroidal invasion. Focality of the tumor is another independent risk factor for metastasis.

Ultrasonic Characteristics of Medullary Thyroid Carcinoma: Differential From Papillary Thyroid Carcinoma and Benign Thyroid Nodule

ABSTRACT

The aim of this study was to evaluate the differences in ultrasonic features of patients with medullary thyroid carcinoma (MTC), papillary thyroid carcinoma (PTC), and benign thyroid nodules. This study included 53 cases of MTC, 151 cases of PTC, and 200 cases of benign thyroid nodule which were pathologically confirmed. There were no significant differences in sex and thyroid gland involvement among the MTC, PTC, and benign thyroid nodule groups. The age among the 3 groups was statistically different (P = 0.002). The TNM stage of MTC was significantly higher than that of PTC (P < 0.001). Compared with PTC, the lesion size, shape, margin, echogenicity, internal nodule component, and blood flow were significantly different in MTC (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P = 0.045, P < 0.001). However, there were no differences in the form of calcification and cervical lymph node involvement between the 2 groups (P = 0.671, P = 0.128). Except for the lesion size and shape (P = 0.068, P = 0.444), MTC group have significant differences in the grade of Thyroid Imaging Reporting and Data System, lesion margin, echogenicity, internal nodule component, calcification, cervical lymph node, and blood flow compared with benign thyroid nodule group (P < 0.001, P = 0.014, P = 0.032, P < 0.001, P < 0.001, P < 0.001). Our data indicate that ultrasound have important value in preoperative diagnosis of MTC. The ultrasonic features of MTC include relatively large nodules, aspect ratio less than 1, smooth edge, solid hypoechoic, microcalcification, and rich blood flow. It is necessary to combine multiple ultrasonic features for the differential diagnosis of MTC, PTC, and benign thyroid nodules.

Ultrasonographic characteristics of medullary thyroid carcinoma according to nodule size: application of the Korean Thyroid Imaging Reporting and Data System and American Thyroid Association guidelines

BACKGROUND

Few studies have categorized ultrasound (US) findings of various sized medullary thyroid carcinomas (MTCs) according to updated guidelines.

PURPOSE

To evaluate and compare the differences in US findings of MTC according to nodule size, using the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) and American Thyroid Association (ATA) guidelines.

MATERIAL AND METHODS

The study included 119 patients with 129 MTC nodules, which were surgically confirmed at our institution between March 1999 and September 2017. Nodules were divided into large (≥1.0 cm) and small (<1.0 cm) groups. US images were analyzed according to the K-TIRADS and ATA guidelines. The differences in US characteristics between small and large nodules were compared using Fisher's exact or Chi-square tests.

RESULTS

Of 129 MTC nodules, 84 (65.1%) were large nodules and 45 (34.9%) were small nodules. According to the nodule size, small MTC nodules were classified more commonly as high suspicion by K-TIRADS and ATA (95.6% and 93.3%, respectively) (P < 0.001), but presented neither cystic change, isoechogenicity, nor low suspicion category by K-TIRADS and ATA. In contrast, large MTC nodules showed more frequently cystic change (15.5%), isoechogenicity (16.7%), smooth margins (50%), or low or intermediate suspicion US features by K-TIRADS and ATA (59.6% and 36.0%, respectively) (all P values < 0.001).

CONCLUSION

Most small MTC nodules are classified as high suspicion on US, whereas large MTC nodules are diagnosed more frequently as low or intermediate suspicion by K-TIRADS and ATA.

Diagnostic Performance of Neck Ultrasonography in the Preoperative Evaluation for Extrathyroidal Extension of Suspicious Thyroid Nodules

BACKGROUND

A preoperative neck ultrasound (US) is recommended for all patients with suspected thyroid cancer, to identify features potentially changing surgical extent. The extrathyroidal extension (ETE) is considered an indication for total thyroidectomy, but there is limited consensus on its US definition, and the interobserver reliability is low. This study aimed to evaluate the predictive value of neck US for ETE before surgery and to estimate the diagnostic performance of different US findings, evaluated during real-time examinations.

METHODS

Patients referred to surgery between November 1, 2015, and May 31, 2019, for a suspicious thyroid cancer underwent a preoperative neck US, with systematic assessment for ETE. Three definitions were tested: very restrictive (capsular disruption with suspicious images of surrounding tissues invasion), restrictive (including also capsular abutment with evidence of capsular disruption), and nonrestrictive (capsular abutment is sufficient). Histopathology report of ETE involving at least soft tissues was considered positive. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

RESULTS

The study cohort included 128 patients, with 102 (79.7%) confirmed malignancies, and 44 (43.1%) histological ETE. The nonrestrictive definition had good sensitivity (86.4%) but low specificity (29.8%), with an NPV of 80.6%; the restrictive definition had higher specificity (81%), while the very restrictive had specificity and PPV of 100%.

CONCLUSIONS

A more extensive surgical approach should not be based on US suspicion of ETE alone, with the possible exception of gross invasion appearance. The absence of any sign of ETE, on the other hand, has a substantial negative predictive value.

Medullary Thyroid Cancer with Paraganglioma-Like Pattern Diagnosed During Pregnancy: A Case Report and Literature Revision

INTRODUCTION

Medullary thyroid carcinoma (MTC) is an infrequent thyroid malignancy rarely observed and managed during pregnancy. An accurate diagnostic workup is extremely important in this clinical setting to correctly diagnose and treat the disease, avoiding both maternal and fetal complications.

OBJECTIVE

We report our experience in managing an MTC incidentally diagnosed during pregnancy in a 28-year female, highlighting critical aspects through the diagnostic workup. Additionally, we provide a literature revision searching on PubMed terms related to "medullary thyroid carcinoma", "primary thyroid paraganglioma", "paraganglioma-like medullary thyroid cancer" in relationship with a nodular appearance at neck US, serum CT measurement, cytological and histological findings.

METHODS

Specimens for cytological evaluation were stained with the Papanicolaou method while tissue sections were stained with hematoxylin and eosin and Congo red stain. Immunohistochemical evaluation was also performed for thyroid transcription factor-1, enolase, thyroglobulin, cytokeratin, chromogranin A, S-100 protein, glial fibrillary acidic protein, calcitonin and Ki-67.

RESULTS

Serum CT was incidentally found to be elevated in two consecutive venous samples. However, the cytological assessment of the fine needle aspiration (FNAc) showed "cells with round-shaped nuclei and granular chromatin, organized to form nests or syncytial flaps, scattered among histocytes, and immunocytochemical positivity for CT, thyroid transcriptional factor-1, cytokeratin, S-100 protein", highlighting a suspicion of both MTC and intrathyroidal paraganglioma. MTC was finally supposed after the evidence of a really elevated CT (3,726 pg/ml) measurement in the FNA washout fluid. After a careful discussion about both risks and benefits, the patient decided to postpone the surgery after the delivery.

CONCLUSION

The histological diagnosis finally confirmed a rare case of paraganglioma-like MTC (T1 N0 Mx), emphasizing the complexity of our differential diagnosis, between an MTC and a thyroidal paraganglioma. In similar cases, due to a relevant impact on surgical timing, patients should be adequately informed about both risk and benefits of the surgery during pregnancy, and a careful management of the disease is required until and after surgery.

The Diagnostic Value of Ultrasound in Medullary Thyroid Carcinoma: A Comparison With Computed Tomography

Purpose:

To explore the clinical value of ultrasound in the diagnosis of medullary thyroid carcinoma by comparing with enhanced computed tomography.

Methods:

This retrospective study was performed on 62 patients with pathologically confirmed medullary thyroid carcinoma. All patients underwent ultrasound and enhanced computed tomography examinations before surgery. The findings of the pathologic examination of resected specimens were considered as gold standard and were compared with the results of these 2 methods.

Results:

There were 73 medullary thyroid carcinoma lesions and 29 benign lesions in 62 patients. In all, 55 of 73 medullary thyroid carcinoma lesions and 27 of 29 benign lesions were correctly diagnosed by ultrasound; and 45 of 73 medullary thyroid carcinoma lesions and 24 of 29 benign lesions were correctly diagnosed by enhanced computed tomography. The accuracy of ultrasound and enhanced computed tomography was 80.4% and 67.6%, respectively. There was significant difference between 2 methods (P < .05).

Conclusions:

Ultrasound can be used to observe the location, number, size, shape, border, internal echo, calcification, and blood flow of the lesion. It is a convenient, inexpensive, and nonradiative method with higher accuracy than enhanced computed tomography.

Clinical and ultrasonographic features of medullary thyroid microcarcinomas compared with papillary thyroid microcarcinomas: a retrospective analysis

Background

To identify the sonographic features that help to differentiate medullary thyroid microcarcinomas (MTMCs) from papillary thyroid microcarcinomas (PTMCs).

Methods

A total of 46 MTMCs in 41 patients and 136 PTMCs in 104 patients that were proven by surgery and pathology were included in the study. Patient age and nodule size were analyzed by independent sample t-tests, and sex, multiplicity and cervical lymph node metastases were analyzed by χ² or Fisher’s exact tests. Univariate analysis and multivariate logistic regression analysis were performed on the sonographic features of thyroid nodules, including location, shape, boundary, margin, peripheral halo ring, echogenicity, composition, calcifications and vascularization.

Results

Compared with the corresponding number of patients with PTMCs, more MTMC patients had cervical lymph node metastases (P = 0.040). There were no significant differences in age, sex, nodule size, multiplicity, location, boundary, margin, peripheral halo ring, echogenicity or microcalcifications between MTMCs and PTMCs (P > 0.05 for all). However, significant differences were found in shape (P = 0.000), composition (P = 0.032), macrocalcifications (P = 0.004) and vascularity (P = 0.000) between the two groups.

Conclusions

There were some overlapping sonographic features between MTMCs and PTMCs. However, MTMCs tended to have a > 50% solid composition, be ovoid to round nodules with macrocalcifications and be hypervascular. Cervical lymph node metastases were more common in MTMC patients.

The KWAK TI-RADS and 2015 ATA guidelines for medullary thyroid carcinoma: Combined with cell block-assisted ultrasound-guided thyroid fine-needle aspiration

OBJECTIVE

To compare the value of the thyroid imaging reporting and data system proposed by Kwak (KWAK TI-RADS) and the 2015 American Thyroid Association (ATA) guidelines for diagnosis of medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC). To confirm the role of cell block (CB)-assisted fine-needle aspiration (FNA) in final diagnosis of MTC.

DESIGN

Retrospective hospital-based cohort study.

PATIENTS

Ninety-three patients with 29 MTCs, 31 PTCs and 33 thyroid adenomas (TAs) who underwent thyroidectomy from January 2010 to May 2019 were retrospectively reviewed. The KWAK TI-RADS and ATA guidelines were used to assess each thyroid nodule. FNA, CB-assisted FNA and core needle biopsy (CNB) were performed in final diagnosis.

RESULTS

Age and ultrasound features (composition, echogenicity and shape) were significantly different between MTC and PTC. Sex and ultrasound features (echogenicity, margin and calcification) were significantly different between MTC and TA. The KWAK TI-RADS and ATA guidelines showed no significant difference for MTC (area under the curve [AUC]: 0.812 and 0.808; P = .37-.85) or PTC (AUC: 0.883 and 0.885; P = .25-.96). The KWAK TI-RADS and ATA guidelines showed high specificity and sensitivity for MTC (93.9% and 62.1%, 87.9% and 65.5%) and PTC (93.9% and 67.7%, 87.9% and 77.4%), respectively. For suspicious MTC (7 cases), CB-assisted FNA provide accuracy preoperative diagnosis.

CONCLUSIONS

Although the diagnostic performance of the TI-RADS and ATA guidelines is worse for MTC than PTC, the difference is not statistically significant. CB-assisted FNA should be performed in thyroid nodules with 4a or lower suspicion to avoid misdiagnosis of MTC.

Diagnosis and pathologic characteristics of medullary thyroid carcinoma-review of current guidelines

Background

Medullary thyroid carcinoma (mtc) is a rare malignancy of the thyroid gland, and raising awareness of the recommended diagnostic workup and pathologic characteristics of this malignancy is therefore important.

Methods

We reviewed the current clinical practice guidelines and recent literature on mtc, and here, we summarize the recommendations for its diagnosis and workup. We also provide an overview of the pathology of mtc.

Results

A neuroendocrine tumour, mtc arises from parafollicular cells ("C cells"), which secrete calcitonin. As part of the multiple endocrine neoplasia (men) type 2 syndromes, mtc can occur sporadically or in a hereditary form. This usually poorly delineated and infiltrative tumour is composed of solid nests of discohesive cells within a fibrous stroma that might also contain amyloid. Suspicious nodules on thyroid ultrasonography should be assessed with fine-needle aspiration (fna). If a diagnosis of mtc is made on fna, patients require baseline measurements of serum calcitonin and carcinoembryonic antigen. Calcitonin levels greater than 500 pg/mL or clinical suspicion for metastatic disease dictate the need for further imaging studies. All patients should undergo dna analysis for RET mutations to diagnose men type 2 syndromes, and if positive, they should be assessed for possible pheochromocytoma and hyperparathyroidism.

Summary

Although the initial diagnosis of a suspicious thyroid nodule is the same for differentiated thyroid carcinoma and mtc, the remainder of the workup and diagnosis for mtc is distinct.

Diagnostic value of fine-needle aspiration combined with ultrasound for thyroid cancer

Diagnostic value of fine-needle aspiration (FNA) combined with ultrasound for thyroid cancer was evaluated. A retrospective analysis was performed on the preoperative FNA and ultrasound data of 165 thyroid nodule patients, were divided into group A (≤1 cm group) and group B (>1 cm group) based on the maximum diameter line of the thyroid nodule. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of FNA, ultrasound and FNA combined with ultrasound in the diagnosis of thyroid cancer were analyzed and compared. In group A (≤1 cm group), the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of FNA in the diagnosis of thyroid cancer were 93.33, 71.43, 91.04, 96.55 and 55.56%, respectively, those of ultrasound were 86.67, 28.57, 80.60, 91.23 and 20%, respectively, and those of FNA combined with ultrasound were 100, 28.57, 92.54, 92.6 and 100%, respectively, with statistically significant differences in the sensitivity, specificity, accuracy, positive predictive value and negative predictive value between FNA, ultrasound and FNA combined with ultrasound (P<0.05). In group B, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of FNA in the diagnosis of thyroid cancer were 100, 54.55, 94.90, 94.57 and 100%, respectively, those of ultrasound were 96.55, 72.73, 93.88, 96.55 and 72.73%, respectively, and those of FNA combined with ultrasound were 100, 63.64, 97.96, 95.92 and 100%, respectively, without statistically significant differences in the sensitivity, specificity, accuracy, positive predictive value and negative predictive value between FNA, ultrasound and FNA combined with ultrasound (P>0.05). FNA combined with ultrasound significantly improved the sensitivity and accuracy in the diagnosis of the thyroid nodule in group A, but it did not significantly improve the accuracy, sensitivity and specificity in the diagnosis of the thyroid nodule in group B.

The application value of modified thyroid imaging report and data system in diagnosing medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is highly malignant and quite different from the most common papillary thyroid carcinoma (PTC). However, most of the ultrasonic evaluation systems mainly aim at PTC at present. This study aims to evaluate the applicability of modified TI-RADS in diagnosing MTC and compare the sonographic differences of MTC, PTC, and benign nodules. Three thousand two hundred and forty-two thyroid nodules images confirmed by pathology were categorized according to modified TI-RADS and ACR TI-RADS classification. The performances of two TI-RADS were assessed by ROC curves. The correlations between classifications with the pathology and the consistency of different doctors were evaluated. The ultrasonic differences of MTC, PTC, and benign nodules were analyzed. As a result, the number of high suspicious US features increased, the malignant risk of nodules also increased of two classifications, with significant differences between categories (P < 0.001). Spearman correlation coefficients were 0.751 (modified TI-TADS) and 0.744 (ACR TI-RADS). Areas under the ROC curve of the modified TI-RADS and ACR TI-RADS were 0.960 and 0.872 (P < 0.001). At Best cut off points, the diagnostic value of modified TI-RADS was higher than that of ACR TI-RADS with a higher specificity, PPV, accuracy, and Youden index). By using modified TI-RADS to diagnose MTC and PTC, the sensitivity, specificity, NPV, accuracy, and Youden index were higher in MTC than PTC. The Kendall's correlation coefficients were 0.962, 0.930, and 0.987. MTC had special ultrasonography characters compared with PTC and benign nodules. These results suggest that modified TI-RADS is better than ACR TI-RADS in diagnosing thyroid carcinomas. Diagnostic value to MTC of modified TI-RADS is slightly higher than that to PTC, and the categorical results of different doctors were consistent. MTC had several particular features contrast to PTC and benign nodules.

Medullary thyroid carcinoma: Application of Thyroid Imaging Reporting and Data System (TI-RADS) Classification

PURPOSE

To evaluate the applicability of ultrasound (US)-based Thyroid Imaging Reporting and Data System (TI-RADS) for evaluating medullary thyroid carcinoma (MTC).

MATERIALS AND METHODS

US images and medical records of patients with cytopathology-confirmed MTC between June 2003 and November 2016 were retrospectively reviewed. Four independent reviewers (two experienced and two inexperienced radiologists) evaluated 57 pre-operative US images of patients with MTC for shape, composition, echogenicity, margin, calcification of the MTC nodules, and categorized the nodules using TI-RADS classification. Weighted Kappa statistics was used to determine the inter-observer agreement of TI-RADS. Univariate and multivariate analyses were performed to assess US findings associated with lymph node metastasis.

RESULTS

Ninety-five percent of nodules were classified as either high suspicion (68%) or intermediate suspicion (26%). The overall inter-rater agreement was good (Kappa 0.84, agreement 91.52%), and inexperienced reviewers also showed good agreements with the most experienced reviewer (weighted Kappa 0.73 and 0.81). According to the univariate analysis, TI-RADS category 5, shape, microcalcification, and extrathyroid extension were significantly associated with lymph node metastasis in MTC patients (p = 0.003, 0.008, 0.001, and 0.021, respectively). As per the multivariate analysis, the presence of microcalcification and the irregular shape of the nodule were significantly associated with metastatic lymph nodes in MTC patients (odds ratio, 26.6; 95% CI, 2.7-263.7, p = 0.005, odds ratio, 14.7; 95% CI, 1.3-170, p = 0.031, respectively).

CONCLUSION

TI-RADS is applicable for the evaluation of MTC nodules with good inter-observer agreement.

Ultrasonographic characteristics of medullary thyroid carcinoma: a comparison with papillary thyroid carcinoma

This study was designed to explore differences in the ultrasonographic characteristics of medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC). This study included 35 cases of MTC and 96 cases of PTC that were surgically and pathologically confirmed. Preoperative ultrasound images were retrospectively reviewed by two physicians (with 5 years’ experience in thyroid ultrasound) under the premise of unknown pathological results. Various ultrasonic features of nodules were assessed objectively. The clinical features of components were determined by other physicians. Age, sex, unilateral or bilateral involvement of thyroid gland, lesion size, margin, shape, echogenicity, calcification, intranodular blood flow, cervical lymph node, and tumor node metastasis (TNM) stage were compared between MTC and PTC groups. Age, sex, involvement of the thyroid gland, margin, and calcification were similar for the MTC and PTC groups. Compared with the PTC group, the lesion size in the MTC group was significantly larger (P < 0.001). A taller-than-wide shape (aspect ratio > 1) was significantly less likely in the MTC group than the PTC group (P < 0.001). A mixed echogenicity was significantly more common in the MTC group than the PTC group (P = 0.003). The MTC group had significantly enhanced intranodular blood flow (P < 0.001). The TNM stage of the MTC group was significantly higher than that of PTC group (P = 0.001). Medullary thyroid carcinomas differ significantly from PTCs in lesion size, shape, echogenicity, and intranodular blood flow.

Hypervascularity is more frequent in medullary thyroid carcinoma: Compared with papillary thyroid carcinoma

This study was designed to retrospectively compare the sonographic features of medullary thyroid carcinoma (MTC) and the features of papillary thyroid carcinoma (PTC).A total of 97 patients with 127 MTCs between January 2000 and January 2016 and 107 consecutive patients with 132 PTCs were included in this study. Two radiologists retrospectively determined the sonographic features and compared the findings of MTCs and PTCs.Compared with the patients with PTCs, the patients with MTCs were older (46.9 years vs 42.9 years, P = 0.016) and the male proportion was higher (53.6% vs 33.6%, P = 0.005). Most of the MTCs had an irregular shape (72.4%), a length/width ratio <1 (75.6%), an unclear boundary (63.8%), no peripheral halo ring (93.7%), hypoechogenicity (96.9%), heterogeneous echotexture (76.4%), no cystic change (78.7%), calcification (63.8%), and hypervascularity (72.4%). There was no significant difference in the boundary, peripheral halo ring, echogenicity, and calcification between the MTCs and PTCs. However, compared with the PTCs, a larger size (2.2 vs 1.2 cm, P <0.001), a regular shape (27.6% vs 7.6%, P <0.001), a length/width ratio <1 (75.6% vs 51.5%, P<0.001), heterogeneous echotexture (76.4% vs 54.5%, P <0.001), cystic change (21.3 vs 8.3%, P = 0.005), and hypervascularity (72.4% vs 47.7%, P <0.001) were more frequent in the MTCs.The sonographic features with a higher likelihood of malignancy are common in MTCs, including a shape taller than the width, irregular infiltrative margins, an absent halo, hypoechogenicity, the presence of microcalcifications, and increased intranodular vascularity. However, MTCs tend to possess these suspicious sonographic features less often than PTCs, with the exception of hypervascularity, which was more frequent in MTCs.

Malignancy is associated with microcalcification and higher AP/T ratio in ultrasonography, but not with Hashimoto's thyroiditis in histopathology in patients with thyroid nodules evaluated as Bethesda Category III (AUS/FLUS) in cytology

The predictors of malignancy are important for the decision of appropriate management in nodules with atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS). Our aim was to determine the ultrasonographical, clinical, and biochemical predictors of malignancy in these patients. A total of 427 patients with cytologically Bethesda Category III (AUS/FLUS) thyroid nodules were included in this retrospective study. We divided the nodules into two subgroups according to the histopathology as benign and malignant, and compared the preoperative ultrasonographical, clinical, and biochemical findings. In overall, 427 patients with 449 AUS/FLUS nodules who had undergone surgery, the rate of malignancy was 23.4 % (105/449). When evaluated separately, the rate of malignancy was 25.8 % in nodules with AUS (82/318) and 17.6 % in nodules with FLUS (23/131) (p = 0.061). The vast majority of malignant specimens in histopathology consisted of papillary thyroid carcinoma (PTC) (n = 91, 86.7 %). Preoperative ultrasonographic features of 105 malignant nodules in histopathology were compared with the 344 benign nodules in histopathology. Anteroposterior/Transverse (AP/T) ratio was significantly higher in malignant group compared to benign group (p = 0.013). In multiple logistic analysis, we found that higher AP/T ratio and microcalcification were independently associated with malignancy (p < 0.05). The malignancy-associated cut-off value of AP/T ratio at maximum sensitivity and specificity was ≥0.81. We did not find any correlation between malignancy and Hashimoto's thyroiditis in histopathology in multivariate analysis (p > 0.05). In Bethesda Category III nodules with higher AP/T ratio and microcalcification, surgery might be considered as a first therapeutic option instead of repeat fine-needle aspiration biopsy or observation.

Charting a course through the CEAs: diagnosis and management of medullary thyroid cancer

Medullary thyroid cancer (MTC) is an uncommon thyroid cancer that requires a high index of suspicion to facilitate diagnosis of early-stage disease amenable to surgical cure. The challenges of diagnosis, as well as management in the setting of persistent disease, are explored in the context of a case presenting with the incidental finding of elevated carcinoembryonic antigen (CEA) and an (18) F-fluorodeoxyglucose positron emission tomography ((18) F-FDG-PET)-positive thyroid incidentaloma detected following treatment of colorectal cancer. Strategies to individualize prognosis, and emerging PET-based imaging modalities, particularly the potential role of (18) F-DOPA-PET in staging, are reviewed.

New American Thyroid Association Sonographic Patterns for Thyroid Nodules Perform Well in Medullary Thyroid Carcinoma: Institutional Experience, Systematic Review, and Meta-Analysis

BACKGROUND

The 2015 American Thyroid Association (ATA) thyroid nodule guidelines recommend selecting nodules for biopsy based on a sonographic pattern classification. These patterns were developed based on features of differentiated thyroid cancer. This study aimed to evaluate the performance and the inter-observer agreement of this classification system in medullary thyroid carcinoma (MTC).

METHODS

The medical records of all patients with MTC evaluated at the authors' institution between 1998 and 2014 were retrospectively reviewed. Only patients with presurgical thyroid ultrasound available for review were included in the study. Five independent reviewers assessed the stored ultrasound images for composition, echogenicity, margins, presence of calcifications, and extrathyroidal extension for each nodule. The presence of suspicious lymph nodes was also evaluated when presurgical lateral neck ultrasound was available for review. Each nodule was classified according to the ATA sonographic patterns. Inter-observer agreement was calculated for each sonographic feature and for the sonographic patterns. To validate the findings, a systematic review of the literature and meta-analysis on the sonographic features of MTC was conducted.

RESULTS

In this institutional cohort, the inter-observer agreement for individual sonographic features was moderate to good (κ = 0.45-0.71), and for the ATA classification it was good (κ = 0.72). Ninety-seven percent (29/30) of the MTCs were classified in the intermediate or high suspicion patterns. A total of 249 MTCs were included in the meta-analysis. Based on pooled frequencies for solid composition and hypoechogenicity, >95% of MTCs would be classified at least in the intermediate suspicion pattern, warranting the lowest-size threshold for biopsy (≥1 cm).

CONCLUSIONS

The sonographic patterns proposed by the ATA perform well in MTC, and inter-observer agreement is good to very good.

Shear wave elastography in medullary thyroid carcinoma diagnostics

Shear wave elastography (SWE) is a modern method for the assessment of tissue stiffness. There has been a growing interest in the use of this technique for characterizing thyroid focal lesions, including preoperative diagnostics.

AIM

The aim of the study was to assess the clinical usefulness of SWE in medullary thyroid carcinoma (MTC) diagnostics.

MATERIALS AND METHODS

A total of 169 focal lesions were identified in the study group (139 patients), including 6 MTCs in 4 patients (mean age: 45 years). B-mode ultrasound and SWE were performed using Aixplorer (SuperSonic, Aix-en-Provence), with a 4-15 MHz linear probe. The ultrasound was performed to assess the echogenicity and echostructure of the lesions, their margin, the halo sign, the height/width ratio (H/W ratio), the presence of calcifications and the vascularization pattern. This was followed by an analysis of maximum and mean Young's (E) modulus values for MTC (EmaxLR, EmeanLR) and the surrounding thyroid tissues (EmaxSR, EmeanSR), as well as mean E-values (EmeanLRz) for 2 mm region of interest in the stiffest zone of the lesion. The lesions were subject to pathological and/or cytological evaluation.

RESULTS

The B-mode assessment showed that all MTCs were hypoechogenic, with no halo sign, and they contained micro- and/ or macrocalcifications. Ill-defined lesion margin were found in 4 out of 6 cancers; 4 out of 6 cancers had a H/W ratio > 1. Heterogeneous echostructure and type III vascularity were found in 5 out of 6 lesions. In the SWE, the mean value of EmaxLR for all of the MTCs was 89.5 kPa and (the mean value of EmaxSR for all surrounding tissues was) 39.7 kPa Mean values of EmeanLR and EmeanSR were 34.7 kPa and 24.4 kPa, respectively. The mean value of EmeanLRz was 49.2 kPa.

CONCLUSIONS

SWE showed MTCs as stiffer lesions compared to the surrounding tissues. The lesions were qualified for fine needle aspiration biopsy based on B-mode assessment. However, the diagnostic algorithm for MTC is based on the measurement of serum calcitonin levels, B-mode ultrasound and FNAB.

Hashimoto's Thyroiditis Does Not Affect Ultrasonographical, Cytological, and Histopathological Features in Patients with Papillary Thyroid Carcinoma

The association between papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT) is controversial. In this study, we aimed to compare preoperative thyroid functions, ultrasonography (US) features, fine-needle aspiration biopsy (FNAB) results, and histopathological characteristics of PTC in patients with and without HT. Data of 919 PTC patients were reviewed retrospectively. The diagnosis of HT was based on histopathological examination and patients were grouped as HT and non-HT. There were 1321 PTC lesions in 919 patients among which 317 (34.5 %) had coexistent HT. There were no significant differences in nodule volume, longitudinal diameter, texture, echogenicity, marginal regularity, presence of microcalcification and hypoechoic halo, and peripheral vascularization in patients with and without HT (p > 0.05, for all parameters). Macrocalcification was observed more frequently in the non-HT group (p = 0.021). FNAB results were similar in the two groups (p = 0.105). Distribution of variants, capsule invasion, vascular invasion, and extrathyroidal extension were observed with similar rates in the HT and non-HT groups. Lymph node metastasis was significantly higher in patients without HT (p = 0.012). Of the carcinomas, 66.1 % (n = 874) were papillary thyroid microcarcinoma (PTMC). Tumor size was lower in PTMC lesions coexistent with HT (p = 0.026). We observed lower rates of capsule invasion, extrathyroidal extension, and lymph node metastases in PTMC with HT compared to without HT (p = 0.007, p = 0.003, and p = 0.015, respectively). This study showed that US features, FNAB results, and histopathological findings of PTC lesions are not influenced by the presence of HT. However, PTMC seems to be related with less aggressive histopathological behavior in HT.

Use of fine-needle aspirate calcitonin to detect medullary thyroid carcinoma: A systematic review

BACKGROUND

The measurement of calcitonin in washout fluids of thyroid nodule aspirate (FNA-calcitonin) has been reported as accurate to detect medullary thyroid carcinoma (MTC). The results from these studies have been promising and the most updated version of ATA guidelines quoted for the first time that "FNA findings that are inconclusive or suggestive of MTC should have calcitonin measured in the FNA washout fluid." Here we aimed to systematically review published data on this topic to provide more robust estimates.

RESEARCH DESIGN AND METHODS

A comprehensive computer literature search of the medical databases was conducted by searching for the terms "calcitonin" AND "washout." The search was updated until April 2015.

RESULTS

Twelve relevant studies, published between 2007 and 2014, were found. Overall, 413 thyroid nodules or neck lymph nodes underwent FNA-calcitonin, 95 were MTC lesions and 93 (97.9%) of these were correctly detected by this measurement regardless of their cytologic report.

CONCLUSIONS

The present study shows that the above ATA recommendation is well supported. Almost all MTC lesions are correctly detected by FNA-calcitonin and this technique should be used to avoid false negative or inconclusive results from cytology. The routine determination of serum calcitonin in patients undergoing FNA should improve the selection of patients at risk for MTC, guiding the use of FNA-calcitonin in the same FNA sample and providing useful information to the cytopathologist for the morphological assessment and the application of tailored ancillary tests.

Sonographic features of medullary thyroid carcinomas according to tumor size: comparison with papillary thyroid carcinomas

OBJECTIVES

The aim of this study was to evaluate the differences in sonographic features of medullary thyroid carcinomas according to nodule size and compared with findings for papillary thyroid carcinomas.

METHODS

This study included 38 medullary thyroid carcinoma nodules and 91 papillary thyroid carcinoma nodules, which were confirmed by pathologic examination between May 2008 and September 2013. Nodules were divided into those that were greater than 10 mm (large nodules) and 10 mm or less (small nodules). The differences in sonographic features (composition, echogenicity, margin, calcifications, and shape) between groups were analyzed with a χ(2) test.

RESULTS

Large medullary thyroid carcinomas more frequently showed an ovoid-to-round shape and a smooth margin; small medullary thyroid carcinomas more frequently showed a taller-than-wide shape and a spiculated margin; the differences were statistically significant between the groups (P < .05). Compared with papillary thyroid carcinomas, large medullary thyroid carcinomas tended to have an ovoid-to-round shape, a smooth margin, and macrocalcifications and were more frequently diagnosed as indeterminate nodules (P < .05); however, there were no significant differences in the internal composition, calcifications, echogenicity, margin, and shape between small medullary thyroid carcinomas and small papillary thyroid carcinomas (P > .05).

CONCLUSIONS

Our data indicate that the sonographic features of medullary thyroid carcinomas are associated with tumor size; furthermore, the sonographic features of medullary thyroid carcinomas are similar to those of small papillary thyroid carcinomas but greatly different from those of large papillary thyroid carcinomas. Large medullary thyroid carcinomas are more commonly diagnosed as indeterminate nodules by sonography than large papillary thyroid carcinomas, and fine-needle aspiration biopsy or serum calcitonin measurement may be helpful.

Detection rate of FNA cytology in medullary thyroid carcinoma: a meta-analysis

BACKGROUND

The early detection of medullary thyroid carcinoma (MTC) can improve patient prognosis, because histological stage and patient age at diagnosis are highly relevant prognostic factors. As a consequence, delay in the diagnosis and/or incomplete surgical treatment should correlate with a poorer prognosis for patients. Few papers have evaluated the specific capability of fine-needle aspiration cytology (FNAC) to detect MTC, and small series have been reported. This study conducts a meta-analysis of published data on the diagnostic performance of FNAC in MTC to provide more robust estimates.

RESEARCH DESIGN AND METHODS

A comprehensive computer literature search of the PubMed/MEDLINE, Embase and Scopus databases was conducted by searching for the terms 'medullary thyroid' AND 'cytology', 'FNA', 'FNAB', 'FNAC', 'fine needle' or 'fine-needle'. The search was updated until 21 March 2014, and no language restrictions were used.

RESULTS

Fifteen relevant studies and 641 MTC lesions that had undergone FNAC were included. The detection rate (DR) of FNAC in patients with MTC (diagnosed as 'MTC' or 'suspicious for MTC') on a per lesion-based analysis ranged from 12·5% to 88·2%, with a pooled estimate of 56·4% (95% CI: 52·6-60·1%). The included studies were statistically heterogeneous in their estimates of DR (I-square >50%). Egger's regression intercept for DR pooling was 0·03 (95% CI: -3·1 to 3·2, P = 0·9). The study that reported the largest MTC series had a DR of 45%. Data on immunohistochemistry for calcitonin in diagnosing MTC were inconsistent for the meta-analysis.

CONCLUSIONS

The presented meta-analysis demonstrates that FNAC is able to detect approximately one-half of MTC lesions. These findings suggest that other techniques may be needed in combination with FNAC to diagnose MTC and avoid false negative results.

Ultrasound features of medullary thyroid carcinoma correlate with cancer aggressiveness: a retrospective multicenter study

Background

Poor prognosis of medullary thyroid cancer (MTC) with suspicious ultrasound (US) features has been reported. The aim of the study was to investigate the association between preoperative US presentation and aggressiveness features of MTC. Also, US features of MTC were compared with those previously reported.

Methods

Study group comprised 134 MTC from nine different centers. Based on US presentation the nodules were stratified in “at risk for malignancy” (m-MTC) or “probably benign” (b-MTC) lesions.

Results

Eighty nine (66.4%) m-MTC and 45 (33.6%) b-MTC were found. Metastatic lymph nodes (p = 0.0001) and extrathyroid invasiveness (p < 0.0001) were more frequent in m-MTC. There was statistically significant correlation (p = 0.0002) between advanced TNM stage and m-MTC with an Odds Ratio 5.5 (95% CI 2.1–14.4). Mean postsurgical calcitonin values were 224 ± 64 pg/ml in m-MTC and 51 ± 21 in b-MTC (p = 0.003).

Conclusions

This study showed that sonographically suspicious MTC is frequently associated with features of aggressiveness, suggesting that careful preoperative US of MTC patients may better plan their surgical approach.

Ultrasonic features of papillary thyroid microcarcinoma and non-microcarcinoma

The present study analyzed the ultrasonic features of papillary thyroid microcarcinoma (PTMC) and papillary thyroid non-microcarcinoma (non-PTMC) with the aim of improving the diagnostic value of ultrasonography. The ultrasonic features of 328 patients with papillary thyroid carcinoma (PTC), as confirmed by pathology, were retrospectively analyzed. Patients were diagnosed with PTMC if the tumor size was ≤10 mm in diameter or non-PTMC if the tumor size was >10 mm in diameter. The shape, ratio of length/width, boundary, echo, peripheral halo ring, calcification, cystic changes, blood flow, lymph node metastasis and additional accompanying thyroid diseases were compared between the patients with PTMC and non-PTMC. In total, 389 nodules were identified in the 328 patients, including 209 PTMC nodules and 180 non-PTMC nodules. The multifocality rate was 15.9% (52/328). Ultrasound scans detected a total of 371 nodules, while 18 PMTC nodules were missed diagnosed and 57 nodules were misdiagnosed as benign nodules. Statistically significant differences in the boundary, ratio of length/width, cystic changes, blood flow and lymph node metastasis were observed between the PTMC and non-PTMC groups (P<0.05). However, no statistically significant differences were observed with regard to the shape, calcification, peripheral halo rings and additional accompanying thyroid diseases between the two groups (P>0.05). Therefore, ultrasound plays an important role in the diagnosis of PTC, with PTMC and non-PTMC exhibiting different ultrasonic performances.

Elastographic presentation of medullary thyroid carcinoma

Aim of the study was to evaluate the elastographic appearance of medullary thyroid carcinoma (MTC) by a retrospective evaluation of 18 nodules histologically proven as MTC. Free-hand qualitative elastography was performed using Hitachi Logos EUB 7500. The elasticity score (ES), was assessed based on a colour elastogram, the blue colour being correlated with hard tissue, red colour with soft tissue, and green with intermediate hardness. Nodules were classified into four classes. A alleged diagnosis of malignancy was assigned to nodules with ES3 or 4 and a presumptive diagnosis of benignity was assigned to nodules with an ES1 or 2. More than half (55.6 %) of MTCs have a low-intermediate grade of elasticity. The hardest lesions (ES4) were those with ultrasonographic features highly suspicious for malignancy. In conclusion, most of MTCs present an elastographic pattern of benignity. Therefore, qualitative elastography does not add useful information in pointing out MTC on the basis of its hardness. Our data suggest a marginal role for this technique in MTC evaluation.

Calcitonin measurement in aspiration needle washout fluids has higher sensitivity than cytology in detecting medullary thyroid cancer: a retrospective multicentre study

OBJECTIVE

Only few studies analysed the capability of cytology in detecting medullary thyroid cancer (MTC), and they reported a low accuracy of this diagnostic technique. Recently, calcitonin (CT) measurement in aspiration needle washout (FNA-CT) of thyroid and neck lesions has been reported as a sensitive tool for MTC. The aim of this study is to compare the sensitivity of FNA-CT and cytology in detecting MTC and to assess a cut-off value of FNA-CT for clinical practice.

PATIENTS

Thirty-eight MTC lesions from 36 patients were retrospectively studied, diagnosed and treated in four different centres. Furthermore, 52 nonmedullary lesions from subjects undergone biopsy following increased serum CT were collected as a control group.

RESULTS

Cytology detected MTC in 21/37 lesions with 56·8% sensitivity. The median FNA-CT value was 2000 pg/ml (range 58-10 000 pg/ml) in MTC and 2·7 pg/ml (range <2-13 pg/ml) in controls (P < 0·001). Using a cut-off of 39·6 pg/ml, MTC lesions could be identified with 100% sensitivity and specificity. As the most important finding, 14 histologically proved MTC lesions could be detected by FNA-CT, despite they were cytologically diagnosed as benign or nonconclusive.

CONCLUSIONS

This study shows, as the first in a multicentre series, that FNA-CT sensitivity is higher than that of cytology in diagnosing MTC. To avoid false-negative MTC by cytology, CT measurement in aspiration needle washout is to be performed in all patients undergoing biopsy following high serum CT.