Preoperative diagnosis of medullary thyroid carcinoma: fine needle aspiration cytology as compared with serum calcitonin measurement

An audit of medullary thyroid carcinoma from a tertiary care hospital in northwest India

Introduction

Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy originating from parafollicular C cells. It accounts for 5%-10% of all thyroid malignancies.

Methods

An ambispective analysis of pathologically proven MTC presented in a tertiary care hospital in northwest India was performed after considering demography, clinical manifestation, RET mutation status, management, and outcome as denominators.

Results

Among 2,735 thyroid malignancy cases who presented to our institute in the last 10 years (2012-2022), 78 (3%) had MTC with a mean age of presentation of 43 ± 11 years; 60% of them were female. The median duration of symptoms was 23 months (IQR 12-36 months). The most common presenting complaint was goiter with lymphadenopathy (80.8%). Among the atypical presentations, one each had ectopic Cushing's syndrome, hypertensive crisis in pregnancy due to pheochromocytoma, synchronous chondrosarcoma, and Von Hippel-Lindau disease spectrum. Median calcitonin and carcinoembryonic antigen (CEA) levels at presentation were 1,274 pg/mL (n = 64) and 149 ng/mL (n = 39), respectively. Twenty-two patients were germline RET mutation-positive, and they presented at a younger age. Majority of the patients presented with stage IV disease. Surgery was the primary modality of therapy. Twenty-nine patients received radiotherapy and 25 patients received tyrosine kinase inhibitors (TKIs). Nine patients received peptide receptor radiotherapy (PRRT) with Lu-177 with neoadjuvant capecitabine. Median progression-free survival (PFS) was 60 months. Patients without structurally and biochemically residual disease and stable disease after the first modality of therapy (Log-rank 11.4; p = 0.004) had a better PFS. Female patients (Log-rank: 9.5; p = 0.002) had a better PFS than male patients.

Conclusion

This study showed that MTC comprises 3% of thyroid malignancies with a female preponderance. RET mutation-positive patients had a younger age at presentation. Surgery was the first-line therapy. Radiotherapy, TKI, and PRRT were given as a part of second-line or third-line therapy due to persistent disease and/or disease recurrence. The median PFS was better in female patients and in patients who had no residual lesions and stable disease after the primary modality of therapy.

Male gender as a poor prognostic factor in medullary thyroid carcinoma: behavior or biological difference?

BACKGROUND

Due to the low incidence and heterogeneous behavior of medullary thyroid carcinoma (MTC), its prognostic factors are still not well stablished. While several large studies have investigated the impact of gender in differentiated thyroid cancer (DTC), its role in MTC outcomes remains controversial. We aim to identify MTC prognostic features, specially focusing on the role of gender.

METHODS

The present study is a retrospective analysis of 76 patients diagnosed with MTC between 1984 and 2018 at a Portuguese Comprehensive Cancer Center.

RESULTS

Patients presented a median age at diagnosis of 49 years and multiple endocrine neoplasia type 2 (MEN2) was identified in 27.6% of them, with those individuals being significantly younger (P<0.001). Most cases were diagnosed as stage IV disease (46.9%), except for the subgroup detected through presymptomatic genetic screening (55.6% at stage I). The 5- and 10-year survival rates were 87.6% and 75.6%, respectively. Univariate analysis identified male gender (P=0.010), age ≥45 years (P=0.007), presence of distant metastasis at diagnosis (P<0.01), capsule invasion (P=0.004), extrathyroidal invasion (P=0.003) and absence of biochemical cure after surgery (P=0.042) as having a negative impact on prognosis. On multivariate analysis, male gender (P=0.046) remained an independent predictor of mortality, as well as an older age (P<0.001) and the presence of distant metastases (P=0.012).

CONCLUSIONS

Male gender independently predicted worse survival in MTC patients even after adjusting for age and disease stage. The few older studies on the topic pointed to a behavioral explanation regarding medical care seeking patterns by men, but our study and newer genetic and basic-science oriented publications raise the possibility of a true biological difference between genders in the tumorigenesis of MTC that should me further investigated.

Diagnostic value and cost-effectiveness of FNA-CT versus FNAC for medullary thyroid carcinoma

OBJECTIVE

To evaluate the diagnostic performance and cost-effectiveness of calcitonin assays in fine-needle aspiration washout fluid (FNA-CT) compared to fine-needle aspiration cytology (FNAC) for medullary thyroid carcinoma (MTC).

METHODS

A total of 27,404 patients from three medical centres between January 2020 and May 2022 were screened for serum calcitonin (sCT). Of whom, 223 patients met endpoints and were enroled for analyses. Based on sCT levels, patients were divided into two groups (group 1: 10 pg/ml< sCT ≤100 pg/ml and group 2: sCT > 100 pg/ml). The diagnostic performance and cost-effectiveness of FNA-CT and FNAC were compared.

RESULTS

Most patients (N = 25,228; 92.1%) with thyroid nodules had normal sCT levels. In group 1, 24 and 167 nodules were diagnosed as MTC and non-MTC lesions, respectively. FNA-CT showed better performance in diagnosing MTC than FNAC in terms of sensitivity (100.0% vs. 58.3%), negative predictive value (100.0% vs. 94.3%), and overall accuracy (100.0% vs. 94.7%). In group 2, 67 and 7 nodules were diagnosed as MTC and non-MTC lesions, respectively. The diagnostic performance of FNA-CT was superior to FNAC in terms of sensitivity (100.0% vs. 64.2%), negative predictive value (100.0% vs. 22.6%), and overall accuracy (100.0% vs. 67.6%). Furthermore, analysis from the decision tree model showed that FNA-CT was a cost-effective tool for diagnosing MTC lesions.

CONCLUSIONS

FNA-CT can serve as an auxiliary and cost-effective approach for patients with indeterminate sCT levels to detect occult MTC lesions. FNA-CT can be recommended for patients with sCT >100 pg/ml to overcome the high false-negative rate of FNAC.

The dilemma of routine testing for calcitonin thyroid nodule's patients to detect or exclude medullary carcinoma: one single negative test should be valuable as rule-out strategy to avoid further calcitonin measurements over time

PURPOSE

While calcitonin (CT) measurement is recognized as the most accurate tool to diagnose medullary thyroid carcinoma (MTC), its routine use in patients with thyroid nodule (TN) is not universally accepted. The present study raised the question whether a TN patient with an initial normal CT can have suspicious CT levels (i.e., at least >20 pg/ml) later during his follow-up.

METHODS

The historical database of our institution was searched to select TN patients undergone multiple CT tests, having an initial normal CT, and clinically followed up for years. The event of a CT above 20 pg/ml (mild-to-moderate suspicion) and 100 pg/ml (high suspicion) was searched in the follow-up of the included patients.

RESULTS

According to the study design, the study sample encompassed 170 patients (131 female, 39 male) with initial CT value ≤10 pg/ml. On the first CT test, patients were 54.8 years and median CT was 2.1 pg/ml in both females and males. Over a period of 14.5 years and a median clinical follow-up of patients of 53.0 (23.9-102.5) months, MTC could be excluded by histology or cytology in 109 (64%) and clinically in the remaining ones. On the follow-up over time, no patients had CT >20 pg/ml and only two cases had CT just above 10 pg/ml.

CONCLUSION

According to the present results, one single CT testing with normal value could be reasonably used as a rule-out strategy in patients with TN to avoid further CT measurements.

Novel Therapeutics and Treatment Strategies for Medullary Thyroid Cancer

Medullary thyroid cancer is a rare thyroid malignancy with unique management considerations. In general, small intrathyroidal tumors are cured by total thyroidectomy with central compartment dissection, while large tumors and those with disease spread to regional lymph nodes and distant organs (most commonly lung, liver, and bone) are more difficult to cure. The last decade has seen significant progress in the treatment of advanced MTC, largely due to the discovery and availability of novel targeted therapies, including new drugs specifically targeting the RET protooncogone.

Preoperative serum calcitonin may improve initial surgery for medullary thyroid cancer in patients with indeterminate cytology

BACKGROUND

Medullary thyroid cancer (MTC) is rare, with poorer outcomes than differentiated thyroid cancer. We aimed to identify areas for improvement in the pre-operative evaluation of patients with possible MTC in a high-volume endocrine surgery unit in accordance with current practice guidelines. We hypothesised that the selective use of serum calcitonin (sCT) as a biomarker for possible MTC could guide the extent of initial surgical management.

METHODS

We recruited MTC patients between 2000 and 2020 from the Monash University Endocrine Surgery Unit database. Demographics, tumour characteristics, pre-operative evaluation, operative management, and outcomes were analysed.

RESULTS

Of 1454 thyroid cancer patients, 43 (3%) had MTC. Pre-operatively, 36 (84%) patients with MTC confirmed on cytology (28, 65%), elevated sCT (6, 14%) or RET mutation (2, 4%). Of these 36 patients, 31 (86%) had optimal extent of thyroidectomy and lymph node dissection (LND). Five (14%) had less than total thyroidectomy due to nerve injury. Thirty-four patients had compartmental LND. In the 12 (27%) patients with indeterminate or non-diagnostic cytology, 5 had elevated sCT and were managed as above. None of the remaining seven had LND, thus potentially suboptimal surgery.

CONCLUSION

Our findings reflect the rarity of MTC, and the challenges of pre-operative diagnosis. The addition of sCT may improve surgical planning in patients with indeterminate cytology.

Performing Calcitonin Immunocytochemistry on an Additional ThinPrep Slide in Fine-Needle Aspiration Diagnosis of Medullary Thyroid Carcinoma

OBJECTIVES

This study reviewed the institutional experience of performing calcitonin immunostain on an additional ThinPrep slide in fine-needle aspiration (FNA) diagnosis of medullary thyroid carcinoma (MTC).

METHODS

Thyroid FNA cases with MTC suspected or included in the differential diagnosis during cytologic evaluation and calcitonin immunostain performed were retrieved and reviewed.

RESULTS

Calcitonin immunostain was performed in 132 cases with 41 positive, 81 negative, and 10 indeterminate results. All calcitonin-positive cases had a cytologic diagnosis of MTC while all calcitonin-negative cases were cytologically classified as non-MTCs except for two cases suspicious for MTC. In 10 cases with an indeterminate calcitonin result, diagnoses of non-MTC and suspicious for MTC were rendered in 6 and 4 cases, respectively. Histopathologic follow-up was available in 85 (64%) cases. All cytologically diagnosed MTC cases were confirmed on histopathology. In 3 MTC cases with an indeterminate calcitonin result, 1 case was misclassified cytologically as follicular neoplasm. The calculated sensitivity, specificity, positive predictive value, and negative predictive value of calcitonin immunostain were all 100% for diagnosing MTC.

CONCLUSIONS

Our study demonstrates the feasibility of performing calcitonin immunostain on an additional ThinPrep slide. Calcitonin immunocytochemistry is a valuable adjunct test for FNA diagnosis and differential diagnosis of MTC.

Head-to-head comparison of FNA cytology vs. calcitonin measurement in FNA washout fluids (FNA-CT) to diagnose medullary thyroid carcinoma. A systematic review and meta-analysis

PURPOSE

The sensitivity of cytology after fine needle aspiration (FNA-cytology) in detecting medullary thyroid carcinoma (MTC) is low. To overcome this problem, measuring calcitonin (CT) in washout fluid of FNA (FNA-CT) has been largely diffused and showed good performance. However, no evidence-based study exists comparing systematically the sensitivity of FNA-cytology and FNA-CT. This study aimed to systematically review the literature and collect data allowing a head-to-head comparison meta-analysis between FNA-cytology and FNA-CT in detecting MTC lesions.

METHODS

The online databases of PubMed/MEDLINE and Scopus were searched until June 2021. Original articles reporting the use of both FNA-cytology and FNA-CT in the same series of histologically proven MTC lesions were included They were extracted general features of each study, number of MTC lesions (nodule and neck lymph nodes), and true positive and false negatives of both FNA-cytology and FNA-CT.

RESULTS

Six studies were included. The sensitivity of FNA-cytology varied from 20% to 86% with a pooled value of 54% (95% CI 35-73%) and significant heterogeneity. The sensitivity of FNA-CT was higher than 95% in almost all studies with a pooled value of 98% (95% CI 96-100%) without heterogeneity. The sensitivity of FNA-CT was significantly higher than that of FNA-cytology.

CONCLUSIONS

FNA-CT is significantly more sensitive than FNA-cytology in detecting MTC. Accordingly, FNA-CT represents the standard method to use in patients with suspicious MTC lesions, combined with cytology.

Medullary Thyroid Cancer: An Experience from a Tertiary Care Hospital of a Developing Country

Background

Medullary thyroid carcinoma (MTC) is a rare type of thyroid cancer that occasionally occurs as part of MEN2A. The universal treatment of MTC is total thyroidectomy with central lymph node dissection. For disease progression, carcinoembryonic antigen (CEA) and calcitonin (CTN) need to be followed. Our aim was to study the presence and patterns of the above-mentioned characteristics of MTC in our population.

Methodology

This retrospective study was conducted in a tertiary care hospital of Pakistan in which data of thirty-two medullary thyroid cancer patients over the past 20 years were reviewed and analysed after fulfilment of inclusion criteria. Their clinical, pathological, biochemical and treatment modalities were recorded through a retrospective review of their medical record files.

Results

The mean age of patients was 42.88 ± 2.67 years in our study, with a male-to-female ratio of 2:1. Patients with sporadic MTC were 68.8%, while 31.2% were familial. The rates of metastasis were highest in bones followed by lungs and liver. Total thyroidectomy was performed in 26 (81.2%) patients and among those chemotherapy and XRT were performed in one and two patients, respectively. Histologically, the mean tumour size was 7.62 ± 3.64 cm. Median pre-surgery calcitonin was 5756 pg/ml that decreased to 29.3 pg/ml post-surgery. Median pre-surgery CEA level was 246.5 ng/ml that decreased to 6.39 ng/ml post-surgery. Two patients were RET positive.

Conclusion

MTC usually presents in the fourth decade of life with male predominance and mostly sporadic occurrence. Total thyroidectomy with subsequent serial calcitonin and CEA levels thereafter are the mainstay of treatment and follow-up.

Constitutive Cytomorphologic Features of Medullary Thyroid Carcinoma Using Different Staining Methods

(1) Background: Accurate preoperative identification of medullary thyroid carcinoma (MTC) is challenging due to a spectrum of cytomorphologic features. However, there is a scarcity of studies describing the cytomorphologic features as seen on fine-needle aspiration (FNA) smears prepared using different staining methods. (2) Methods: We performed a retrospective study on MTC cases with available FNA slides from 13 hospitals distributed across 8 Asia-Pacific countries. The differences in the constitutive cytomorphologic features of MTC with each cytopreparatory method were recorded. A comparative analysis of cytologic characteristics was carried out with appropriate statistical tests. (3) Results: Of a total of 167 MTC samples retrospectively recruited, 148 (88.6%) were interpreted as MTC/suspicious for MTC (S-MTC). The staining methods used were Papanicolaou, hematoxylin-eosin, and Romanowsky stains. Seven out of the eleven cytologic criteria can be readily recognized by all three cytopreparatory methods: high cellularity, cellular pleomorphism, plasmacytoid cells, round cells, dyshesive cells, salt-and-pepper chromatin, and binucleation or multinucleation. An accurate diagnosis was achieved in 125 (84.5%) of the 148 samples whose FNAs exhibited five or more atypical features. Conclusions: The present work is the first study on MTC to compare the morphological differences among the cytologic staining techniques. We investigated the constitutive features and the reliability of diagnostic parameters. A feasible scoring system based upon cytomorphologic data alone is proposed to achieve a high degree of diagnostic accuracy.

Not all that is miliary is tuberculosis: Metastatic medullary thyroid carcinoma mimicking miliary tuberculosis

Medullary carcinoma of the thyroid should be considered in the differential diagnosis of miliary pattern of micronodules on chest imaging, irrespective of clinical features.

Do medullary thyroid carcinoma patients with high calcitonin require bilateral neck lymph node clearance? A case report

BACKGROUND

In clinical work, 85%-90% of malignant thyroid diseases are papillary thyroid cancer (PTC); thus, clinicians neglect other types of thyroid cancer, such as medullary thyroid carcinoma (MTC).

CASE SUMMARY

We report a 53-year-old female patient with a preoperative calcitonin level of 345 pg/mL. There was no definitive diagnosis of MTC by preoperative fine-needle aspiration cytology or intraoperative frozen pathology, but the presence of PTC and MTC was confirmed by postoperative paraffin pathology. The patient underwent total thyroidectomy and bilateral central lymph node dissection. Close follow-up at 1.5 years after surgery revealed no signs of recurrence or metastasis.

CONCLUSION

The issue in clinical work-up regarding types of thyroid cancer provides a novel and challenging idea for the surgical treatment of MTC. In the absence of central lymph node metastasis, it is worth addressing whether patients with high calcitonin can undergo total thyroidectomy and bilateral central lymph node dissection without bilateral lateral neck lymph node dissection.

Recurrent medullary thyroid carcinoma treated with percutaneous ultrasound-guided radiofrequency ablation: A case report

BACKGROUND

Treatment for neck lymph node metastases after adequate initial surgery in medullary thyroid carcinoma (MTC) has been controversial. Ultrasound (US)-guided radiofrequency ablation (RFA) has been widely used in recurrent well-differentiated thyroid carcinoma. Here, we report for the first time the use of RFA in a patient with recurrent MTC.

CASE SUMMARY

We report the case of a 56-year-old woman with cervical lymph node metastases of MTC. Four years previously, she had undergone a total thyroidectomy and neck lymph node dissection. A neck US revealed many enlarged nodes during the follow-up period. Moreover, the serum calcitonin jumped to 198.17 pg/mL, which strongly indicated the recurrence of MTC. Subsequently, two metastatic lymph nodes were confirmed by US-guided fine-needle aspiration-cytology and fine-needle aspiration-calcitonin, and then the patient was treated with RFA. Four months later, the neck US and a contrast-enhanced US showed obvious shrinkage in the ablation zones, and the serum calcitonin dropped to 11.80 pg/mL.

CONCLUSION

This case suggests that RFA may be an effective and safe treatment for local recurrent MTC.

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.

Cabozantinib and vandetanib for unresectable locally advanced or metastatic medullary thyroid cancer: a systematic review and economic model

BACKGROUND

Medullary thyroid cancer (MTC) is a rare form of cancer that affects patients' health-related quality of life (HRQoL) and survival. Cabozantinib (Cometriq^®; Ipsen, Paris, France) and vandetanib (Caprelsa^®; Sanofi Genzyme, Cambridge, MA, USA) are currently the treatment modality of choice for treating unresectable progressive and symptomatic MTC.

OBJECTIVES

(1) To evaluate the clinical effectiveness and safety of cabozantinib and vandetanib. (2) To estimate the incremental cost-effectiveness of cabozantinib and vandetanib versus each other and best supportive care. (3) To identify key areas for primary research. (4) To estimate the overall cost of these treatments in England.

DATA SOURCES

Peer-reviewed publications (searched from inception to November 2016), European Public Assessment Reports and manufacturers' submissions.

REVIEW METHODS

A systematic review [including a network meta-analysis (NMA)] was conducted to evaluate the clinical effectiveness and safety of cabozantinib and vandetanib. The economic analysis included a review of existing analyses and the development of a de novo model.

RESULTS

The systematic review identified two placebo-controlled trials. The Efficacy of XL184 (Cabozantinib) in Advanced Medullary Thyroid Cancer (EXAM) trial evaluated the efficacy and safety of cabozantinib in patients with unresectable locally advanced, metastatic and progressive MTC. The ZETA trial evaluated the efficacy and safety of vandetanib in patients with unresectable locally advanced or metastatic MTC. Both drugs significantly improved progression-free survival (PFS) more than the placebo (p < 0.001). The NMA suggested that, within the symptomatic and progressive MTC population, the effects on PFS were similar (vandetanib vs. cabozantinib: hazard ratio 1.14, 95% credible interval 0.41 to 3.09). Neither trial demonstrated a significant overall survival benefit for cabozantinib or vandetanib versus placebo, although data from ZETA were subject to potential confounding. Both cabozantinib and vandetanib demonstrated significantly better objective response rates and calcitonin (CTN) and carcinoembryonic antigen (CEA) response rates than placebo. Both cabozantinib and vandetanib produced frequent adverse events, often leading to dose interruption or reduction. The assessment group model indicates that, within the EU-label population (symptomatic and progressive MTC), the incremental cost-effectiveness ratios (ICERs) for cabozantinib and vandetanib are > £138,000 per quality-adjusted life-year (QALY) gained. Within the restricted EU-label population (symptomatic and progressive MTC with CEA/CTN doubling times of ≤ 24 months), the ICER for vandetanib is expected to be > £66,000 per QALY gained. The maximum annual budget impact within the symptomatic and progressive population is estimated to be ≈£2.35M for cabozantinib and ≈£5.53M for vandetanib. The costs of vandetanib in the restricted EU-label population are expected to be lower.

LIMITATIONS

The intention-to-treat populations of the EXAM and ZETA trials are notably different. The analyses of ZETA subgroups may be subject to confounding as a result of differences in baseline characteristics and open-label vandetanib use. Attempts to statistically adjust for treatment switching were unsuccessful. No HRQoL evidence was identified for the MTC population.

CONCLUSIONS

The identified trials suggest that cabozantinib and vandetanib improve PFS more than the placebo; however, significant OS benefits were not demonstrated. The economic analyses indicate that within the EU-label population, the ICERs for cabozantinib and vandetanib are > £138,000 per QALY gained. Within the restricted EU-label population, the ICER for vandetanib is expected to be > £66,000 per QALY gained.

FUTURE RESEARCH PRIORITIES

(1) Primary research assessing the long-term effectiveness of cabozantinib and vandetanib within relevant subgroups. (2) Reanalyses of the ZETA trial to investigate the impact of adjusting for open-label vandetanib use using appropriate statistical methods. (3) Studies assessing the impact of MTC on HRQoL.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016050403.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Cytologic diagnosis of medullary thyroid carcinoma in the Asia-Pacific region

BACKGROUND

The accurate preoperative identification of medullary thyroid carcinoma (MTC) is challenging due to the rarity of tumor and variable cytologic appearance. The Asian experience with diagnosing MTC by fine-needle aspiration (FNA) was scarcely reported.

METHODS

Cases of MTC with available FNA slides were enrolled from 13 hospitals representing 8 Asia-Pacific countries. Clinicopathological information, including sample preparation technique, staining method, original cytologic diagnosis and review diagnosis were collected.

RESULTS

Of a total of 145 MTC cases retrospectively recruited, 99 (68.3%) were initially interpreted as MTC/suspicious for MTC (S-MTC). The distribution of original FNA diagnostic categories was not associated with the staining method or sample preparation technique. The staining methods used were Papanicolaou, hematoxylin-eosin and Romanowsky stains. Liquid-based cytology (LBC) was used only in three countries. After reviewing all cases, the diagnostic rate of MTC/S-MTC increased to 91.7% (133/145). Cases with initially unrecognized MTC had either marked pleomorphism or cytology mimicking papillary carcinoma or follicular neoplasm. Although LBC provided certain benefits, there was no significant difference in diagnostic accuracy between conventional smear and LBC. Immunocytochemistry was available in 38 cases (26.2%), all of which were correctly recognized as MTC.

CONCLUSION

Our report summarizes how MTC is handled in contemporary Asian thyroid FNA practice. Although the detection rate of MTC by cytology alone is less satisfactory, integration with ancillary tests could achieve an excellent performance. The recognition of constitutive cytomorphologic features is needed for each cytopreparatory method, which may result in a lower threshold to initiate further workup for MTC.

Update on the Treatment of Medullary Thyroid Carcinoma in Patients with Multiple Endocrine Neoplasia Type 2

Medullary Thyroid Carcinoma (MTC) is a rare neuroendocrine cancer that accounts for 1-2% of thyroid cancers in the United States (U.S.). While most cases are sporadic, 25% of MTC cases are hereditary. These hereditary cases occur in the setting of Multiple Endocrine Neoplasia Type 2A (MEN2A) or 2B (MEN2B) driven by mutations in the Rearranged during Transfection RET proto-oncogene. This article discusses hereditary MTC in the setting of MEN2 and the treatment options available for it. The first line treatment for this disease is typically a total thyroidectomy and tyrosine kinase inhibitors. Two tyrosine kinase inhibitors, vandetanib and cabozantinib, have been approved for treatment of advanced MTC, but options beyond those are limited. However, several promising treatments are being studied, which are discussed in this review.

Early Diagnosis of Medullary Thyroid Cancer: Are Calcitonin Stimulation Tests Still Indicated in the Era of Highly Sensitive Calcitonin Immunoassays?

Background: Measurements of both basal (b) calcitonin (CT) and calcium (Ca)-stimulated CT (Ca-sCT) levels are performed to identify medullary thyroid cancer (MTC) at an early stage when used as part of the diagnostic workup of thyroid nodules (CT screening). Novel immunochemiluminometric assays, which are highly sensitive and specific for monomeric CT and avoid cross-reactivity, have been introduced over the past decade. No prospectively generated data have so far become available to answer the frequently raised question as to whether Ca-sCT in contrast to bCT alone is helpful and, therefore, still indicated for the early detection of MTC. Methods: Ca-stimulation tests were performed in 149 consecutive patients with thyroid nodules and elevated bCT. Regardless of Ca-sCT levels, all patients had an operation applying a uniform surgical protocol, including thyroidectomy and systematic lymph node dissection. Recently published sex-specific cutoff levels for the differentiation of MTC and other C-cell pathologies (C-cell hyperplasia [CCH]) were used to compare the diagnostic performance of bCT or Ca-sCT alone and in combination using receiver-operating characteristic (ROC) analysis. In addition, CT cutoff levels to predict lateral lymph node metastasis were evaluated for bCT compared with Ca-sCT. Follow-up for all patients was documented and correlated with initial CT levels. Results: MTC was identified in 76 (50.1%) patients, in 21/76 (27.6%) with lymph node and in 4 (5.3%) with distant metastasis. Using predefined cutoff levels, patients could effectively be subdivided into a group above the cutoff level with definitive diagnosis of MTC (100%) and below (gray zone) with a significant overlap of CCH and MTC (all classified as pT1a; males: 19/58 [37.5%], females: 7/41 [17.1%]). The areas under the ROC curve (AUC) were excellent for the diagnosis of MTC in all tests. Determination of bCT proved to be superior for both diagnosing MTC in males (AUC for bCT: 0.894; AUC for Ca-sCT: 0.849) and females (bCT: 0.935; Ca-sCT: 0.868) and also for diagnosing lymph node metastasis in the lateral compartment (males: bCT: 0.925; Ca-sCT: 0.810; females: bCT: 0.797; Ca-sCT: 0.674). Combining both tests did not improve diagnostic accuracy. Using a cutoff level of >85 pg/mL for females and >100 pg/mL for males, the sensitivity for diagnosing lateral neck lymph node metastasis was 100%. Below these cutoff levels, no patient showed persistent or recurrent disease (median follow-up: 46 [ ± 27] months). Conclusions: Predefined sex-specific bCT cutoff levels are helpful for the early detection of MTC and for predicting lateral neck lymph node metastasis. Ca-sCT did not improve preoperative diagnostics. bCT levels >43 and >100 pg/mL for males and of >23 and >85 pg/mL for females are relevant for advising patients and planning the extent of surgery.

Calcitonin testing for detection of medullary thyroid cancer in people with thyroid nodules

BACKGROUND

Thyroid nodules are very common in general medical practice, but rarely turn out to be a medullary thyroid carcinoma (MTC). Calcitonin is a sensitive tumour marker for the detection of MTC (basal calcitonin). Sometimes a stimulation test is used to improve specificity (stimulated calcitonin). Although the European Thyroid Association's guideline advocates calcitonin determination in people with thyroid nodules, the role of routine calcitonin testing in individuals with thyroid nodules is still questionable.

OBJECTIVES

The objective of this review was to determine the diagnostic accuracy of basal and/or stimulated calcitonin as a triage or add-on test for detection of MTC in people with thyroid nodules.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase and Web of Science from inception to June 2018.

SELECTION CRITERIA

We included all retrospective and prospective cohort studies in which all participants with thyroid nodules had undergone determination of basal calcitonin levels (and stimulated calcitonin, if performed).

DATA COLLECTION AND ANALYSIS

Two review authors independently scanned all retrieved records. We extracted data using a standard data extraction form. We assessed risk of bias and applicability using the QUADAS-2 tool. Using the hierarchical summary receiver operating characteristic (HSROC) model, we estimated summary curves across different thresholds and also obtained summary estimates of sensitivity and specificity at a common threshold when possible.

MAIN RESULTS

In 16 studies, we identified 72,368 participants with nodular thyroid disease in whom routinely calcitonin testing was performed. All included studies performed the calcitonin test as a triage test. Median prevalence of MTC was 0.32%. Sensitivity in these studies ranged between 83% and 100% and specificity ranged between 94% and 100%. An important limitation in 15 of the 16 studies (94%) was the absence of adequate reference standards and follow-up in calcitonin-negative participants. This resulted in a high risk of bias with regard to flow and timing in the methodological quality assessment. At the median specificity of 96.6% from the included studies, the estimated sensitivity (95% confidence interval (CI)) from the summary curve was 99.7% ( 68.8% to 100%). For the median prevalence of MTC of 0.23%, the positive predictive value (PPV) for basal calcitonin testing at a threshold of 10 pg/mL was 7.7% (4.9% to 12.1%). Summary estimates of sensitivity and specificity for the threshold of 10 pg/mL of basal calcitonin testing was 100% (95% CI 99.7 to 100) and 97.2% (95% CI 95.9 to 98.6), respectively. For combined basal and stimulated calcitonin testing, sensitivity ranged between 82% and 100% with specificity between 99% and 100%. The median specificity was 99.8% with an estimated sensitivity of 98.8% (95% CI 65.8 to 100) .

AUTHORS' CONCLUSIONS

Both basal and combined basal and stimulated calcitonin testing have a high sensitivity and specificity. However, this may be an overestimation due to high risk of bias in the use and choice of reference standard The value of routine testing in patients with thyroid nodules remains questionable, due to the low prevalence, which results in a low PPV of basal calcitonin testing. Whether routine calcitonin testing improves prognosis in MTC patients remains unclear.

Lymph Node Metastases of Medullary Thyroid Cancer: Role of Calcitonin in the Washout Fluid of Fine-Needle Aspiration

INTRODUCTION

The diagnostic value of calcitonin (CT) measurement in fine-needle aspirate washout (FNA-CT) for medullary thyroid cancer (MTC) lymph node (LN) metastases remains to be determined. It may increase the diagnostic sensitivity, but data on this subject is sparse.

OBJECTIVE

Our study aimed to evaluate the utility of FNA-CT in the diagnosis of LN metastases of MTC.

METHODS

We retrospectively investigated, in our institutional database, 69 consecutive FNA LN cytology from 42 patients who underwent FNA cytology and CT measurement in needle washout for suspicious LN between 2012 and 2017.

RESULTS

From the total of 69 FNA, 30 (43.4%) were performed in patients with personal history of MTC. MTC was detected in 19 FNA cytology (27.5%), and CT was detectable in needle washout in 23 cases (median = 2014 pg/mL; interquartile range = 490-15111 pg/mL). Based on the combined results of FNA-CT and FNA cytology, LN surgical resection was performed in 33 cases (47.8%). Histology reported MTC LN metastases in 21 lesions (63.6%). Regarding the diagnosis of MTC LN metastases, FNA cytology showed sensitivity of 81.8% and specificity of 97.9%, and FNA-CT demonstrated sensitivity of 100% and specificity of 97.9%. We determined through ROC analysis an optimal FNA-CT cut-off value of 23 pg/mL for the diagnosis of LN metastases (sensitivity 100%; specificity 100%).

CONCLUSIONS

FNA-CT may be a valuable diagnostic tool for detection of MTC LN metastases, along with FNA cytology, and it should be included in the clinical workup of neck adenopathies in patients with MTC or with thyroid nodules.

Medullary thyroid carcinoma with double negative calcitonin and CEA: a case report and update of literature review

BACKGROUND

Medullary thyroid carcinoma is a malignant uncommon and aggressive tumour of the parafollicular C cells. In about 75% of cases it is sporadic while, in case of RET mutation, it is associated to multiple endocrine neoplasia type 2 (25% of cases). The biochemical features of medullary thyroid carcinoma include the production of calcitonin and carcinoembryogenic antigen. The above-mentioned features are useful in the diagnostic process as well as in the follow up and in the prognostication of the disease. Even if calcitonin elevation is strongly associated to MTC, it can also be found increased in many pathological different conditions as pregnancy, lactation, C-cells hyperplasia, autoimmune thyroiditis, end stage renal disease, lung and prostate cancer and several neuroendocrine tumours. Major medullary thyroid tumours are usually connected to high doses of circulating calcitonin, in fact non-secretory variants have hardly been described.

CASE PRESENTATION

We herein report the case of a 59 years old male, who had undergone total thyroidectomy for multinodular goiter with negative preoperative calcitonin, showing medullary thyroid carcinoma at definitive pathology. To the best of our knowledge, this is the first case documenting a non-secretory medullary thyroid carcinoma, with double negative markers at the time of diagnosis and at the relapse.

CONCLUSION

A Literature review underlining pathological hypothesis, differential diagnosis and alternative and innovative biomarkers to identify non-secretory medullary thyroid carcinoma was carried out.

Medullary Thyroid Carcinoma: An Update on Imaging

Medullary thyroid carcinoma (MTC), arising from the parafollicular C cells of the thyroid, accounts for 1–2% of thyroid cancers. MTC is frequently aggressive and metastasizes to cervical and mediastinal lymph nodes, lungs, liver, and bones. Although a number of new imaging modalities for directing the management of oncologic patients evolved over the last two decades, the clinical application of these novel techniques is limited in MTC. In this article, we review the biology and molecular aspects of MTC as an important background for the use of current imaging modalities and approaches for this tumor. We discuss the modern and currently available imaging techniques—advanced magnetic resonance imaging (MRI)-based techniques such as whole-body MRI, dynamic contrast-enhanced (DCE) technique, diffusion-weighted imaging (DWI), positron emission tomography/computed tomography (PET/CT) with 18F-FDOPA and 18F-FDG, and integrated positron emission tomography/magnetic resonance (PET/MR) hybrid imaging—for primary as well as metastatic MTC tumor, including its metastatic spread to lymph nodes and the most common sites of distant metastases: lungs, liver, and bones.

Calcitonin Screening in Nodular Thyroid Disease: Is There a Definitive Answer?

INTRODUCTION

Calcitonin (Ctn) is a hormone secreted by thyroid "C" cells and is considered an excellent marker for medullary thyroid carcinoma (MTC). However, the use of Ctn to screen patients with nodular thyroid disease (NTD) remains controversial.

OBJECTIVE

The aim of this work was to define the frequency of hypercalcitoninemia among NTD patients followed at a tertiary referral hospital.

METHODS

A retrospective analysis was made of basal Ctn measurements and corresponding patients' records between January 2011 and December 2015. Hypercalcitoninemia was defined as > 10 pg/mL. Depending on the Ctn value, three groups were considered: G1, ≤10 pg/mL; G2, 10-100 pg/mL; G3, ≥100 pg/mL.

RESULTS

Ctn was requested in an NTD context for 1,504 patients, 69 of whom had hypercalcitoninemia. Of these, 20 underwent surgery (G2, 11; G3, 9), and a histological diagnosis of MTC was established in 12 (G2, 3/27%; G3, 9/100%). Surgery was chosen based solely on Ctn levels in 7 cases, since only 5 had a positive cytology.

CONCLUSIONS

Hypercalcitoninemia was found in 4.6% of NTD patients. Ctn levels ≥100 pg/mL were associated with a greater CMT risk than values between 10 and 100 pg/mL, reinforcing results from other groups. The need for an adequate interpretation of results as well as an appropriate selection of patients to surgery stresses the importance of endocrinologists requesting and interpreting results.

A pioneering RET genetic screening study in the State of Ceará, Brazil, evaluating patients with medullary thyroid cancer and at-risk relatives: experience with 247 individuals

OBJECTIVE

Initial diagnosis of medullary thyroid carcinoma (MTC) is frequently associated with advanced stages and a poor prognosis. Thus, the need for earlier diagnoses and detection in relatives at risk for the disease has led to increased use of RET genetic screening.

SUBJECTS AND METHODS

We performed RET screening in 247 subjects who were referred to the Brazilian Research Consortium for Multiple Endocrine Neoplasia (BRASMEN) Center in the State of Ceará. Direct genetic sequencing was used to analyze exons 8, 10, 11, and 13-16 in MTC index cases and specific exons in at risk relatives. Afterward, clinical follow-up was offered to all the patients with MTC and their affected relatives.

RESULTS

RET screening was performed in 60 MTC index patients and 187 at-risk family members. At the initial clinical assessment of the index patients, 54 (90%) were diagnosed with apparently sporadic disease and 6 (10%) diagnosed with hereditary disease. After RET screening, we found that 31 (52%) index patients had sporadic disease, and 29 (48%) had hereditary disease. Regarding at-risk relatives, 73/187 were mutation carriers. Mutations in RET codon 804 and the rare p.M918V mutation were the most prevalent.

CONCLUSIONS

Performing RET screening in Ceará allowed us to identify a different mutation profile in this region compared with other areas. RET screening also enabled the diagnosis of a significant number of hereditary MTC patients who were initially classified as sporadic disease patients and benefited their relatives, who were unaware of the risks and the consequences of bearing a RET mutation.

Calcitonin measurement in fine-needle aspirate washout fluid by electrochemiluminescence immunoassay for thyroid tumors

Purpose

For the differential diagnosis of medullary thyroid carcinoma (MTC) on thyroid nodules, ultrasound-guided fine-needle aspiration cytology is a useful and safe procedure, but its diagnostic accuracy is not high enough. As an ancillary method to accurately diagnose MTC, the calcitonin in fine-needle aspirate washout fluid (FNA-Ct) is used. However, no data are available about cut-off values of FNA-Ct using the currently available electrochemiluminescence immunoassay (ECLIA).

Methods

We investigated 180 thyroid nodules in 141 patients. After smearing, the syringe and needle used for the FNA were rinsed with normal saline (0.5 mL). The calcitonin in the washout was measured by ECLIA.

Results

The FNA-Ct in the non-MTC nodules of MTC patients, non-MTC nodules of non-MTC patients, and MTC nodules were 10.6-2100 pg/mL (median 24.6 pg/mL), < 0.5-21.0 pg/mL (median < 0.5 pg/mL), and 94.9-4,070,000 pg/mL (median 177,000 pg/mL), respectively. A receiver operating characteristic analysis of the MTC nodules and the non-MTC nodules of the non-MTC patients indicated that the cut-off value was 21.0 pg/mL, leading to 100% sensitivity and 100% specificity.

Conclusions

This is the first study to determine the cut-off value of FNA-Ct with an ECLIA, and we propose that the optimal cut-off value is 21.0 pg/mL.

Serum calcitonin negative mixed medullary-follicular carcinoma initially diagnosed as medullary thyroid carcinoma by fine-needle aspiration cytology: A case report and review of the literatures

Medullary thyroid carcinoma (MTC) is potentially lethal. A prompt and accurate diagnosis is the prerequisite for the treatment of MTC. Fine-needle aspiration (FNA) is a reliable diagnostic tool in the assessment of thyroid nodules. However, cytologic assessment of MTC based on FNA has several drawbacks due to morphological variants. We present a case of MTC diagnosed through FNA cytology, which was eventually histologically confirmed as a mixed medullary-follicular carcinoma with negative serum calcitonin expression. Hence, diagnosis of MTC based on FNA should be applied with caution. Ultrasound characteristics of suspicious thyroid nodules are recommended to be evaluated by FNA. However, calcitonin levels should be measured in both the FNA washout fluid and serum when features of MTC are presented or cytology result is inconclusive. If adequate FNA sample is available, a supplementary immunocytochemical staining of markers such as calcitonin, chromogranin, carcinoembryonic antigen, and thyroglobulin is helpful for a correct diagnosis of MTC.

Thyroid Cancer: Risk-Stratified Management and Individualized Therapy

Thyroid cancer is the most common endocrine malignancy. Differentiated thyroid cancer (DTC) with the two subtypes, papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC), is the most frequent subtype of thyroid cancer; more rare subtypes are medullary thyroid cancer (MTC) and anaplastic thyroid cancer (ATC). The incidence of DTC has increased rapidly in recent years due to the more frequent use of imaging methods such as ultrasound of the neck and fine-needle aspiration (FNA) of thyroid nodules. After total thyroidectomy and radioiodine treatment, DTC remains an indolent and curable disease in most patients, whereas the cure rate in MTC is lower and depends on early diagnosis. Most ATCs are incurable. In recent years, there has been great progress in identifying genetic changes in thyroid cancer, and genetic testing of FNA samples or blood samples provides useful information for clinical decision making. Tumor staging, either postoperatively or by imaging, and measuring the tumor markers thyroglobulin for DTC and calcitonin for MTC, allow for dynamic risk-adapted stratification for follow-up procedures. In advanced metastatic thyroid cancer, molecular targeted therapy using tyrosine kinase receptor inhibitors, including sorafenib, lenvantinib, vandetanib, and cabozantinib, helps control tumor progression and prolongs progression-free survival. Using a dynamic risk-stratified approach to manage thyroid cancer, the outcomes for most thyroid cancer patients are excellent compared with those for other cancers. The major challenge in the future is to identify high-risk patients and to treat and monitor them appropriately. Clin Cancer Res; 22(20); 5012-21. ©2016 AACR SEE ALL ARTICLES IN THIS CCR FOCUS SECTION, "ENDOCRINE CANCERS REVISING PARADIGMS".

Outcome of Treatment for Medullary Thyroid Carcinoma-a Single Centre Experience

We conducted this study to evaluate the demography, clinical presentation, management and outcomes of medullary thyroid carcinoma (MTC) from the Indian context. This was a retrospective study of patients with MTC managed between January 2008 and December 2016. All pertinent data was collected and the results were analysed using STATA (v.13.1). MTC accounted for 90/2022 (4.45%) patients managed with thyroid cancer during the study period. The mean age of presentation was 40 years (range 14-70 years) with 47 males and 43 females. The most common presentation included goitre with cervical lymphadenopathy seen in 60 patients (66.7%). There were 11 patients (12.2%) with systemic metastasis at presentation. Rearranged during transfection (RET) testing was performed in 71 patients and was positive in 25 (35.2%). The mutations among these patients were seen in the following codons: 634 (12), 804 (8), 790 (3) and 618 (2). Persistent hypercalcitoninemia (calcitonin > 50 pg/ml) was observed in 62/80 (77.5%) patients. Forty patients underwent a meta-iodo-benzyl-guanidine (MIBG) scan in the postoperative period, 10 were positive. The mean duration of follow-up was 32 months and 10 patients defaulted from follow-up. Sixteen patients developed metastasis during the period of follow-up while eight patients expired. The mean survival was 85.75 months (95% CI 78.7-92.7). MTC accounted for 4.5% of thyroid carcinomas in this cohort among which 35% were hereditary. Persistent hypercalcitoninemia following surgery is seen in more than 70% of patients but this does not affect survival. RET screening should be performed for all patients with MTC as curative surgery can be offered for mutation positive offspring.

Serum calcitonin reference values for calcium stimulation tests by electrochemiluminescence immunoassay in Japanese men with non-medullary thyroid carcinoma

PURPOSE

Calcitonin is the most sensitive tumor marker of medullary thyroid carcinoma (MTC) and a calcium stimulation test is used to improve this sensitivity. In Japan, the electrochemiluminescence immunoassay (ECLIA) is currently the only test performed to measure serum calcitonin. There is a gender difference in the reference value of serum calcitonin; however, a reference upper limit for use with ECLIA has been reported only for women, but not for men.

METHODS

We conducted the calcium stimulation test using ECLIA in 21 men with non-medullary thyroid carcinoma (non-MTC), before and after total thyroidectomy.

RESULTS

Preoperatively, the basal calcitonin values were within normal limits in all patients. They increased to a mean value of 37.6 pg/mL after calcium stimulation, and we calculated that the reference upper limit was 83.7 pg/mL. The stimulation test results after total thyroidectomy showed undetectable basal and stimulated calcitonin values in every patient (<0.5 pg/mL).

CONCLUSIONS

To our knowledge, this is the first study to calculate reference values for this stimulation test using an ECLIA in men with non-MTC. We propose that men can be regarded as biochemically cured or as having normal serum calcitonin values when the stimulated calcitonin values obtained by ECLIA are <83.7 pg/mL before and <0.5 pg/mL after total thyroidectomy.

Measurement of thyroglobulin, calcitonin, and PTH in FNA washout fluids

Different imaging tools, circulating endocrine markers, and fine-needle aspiration (FNA) cytology are of great importance in the diagnosis and follow-up of different thyroid and parathyroid diseases. Sometimes, however, they are conflicting or inconclusive: interestingly, measuring endocrine markers (i.e. thyroglobulin, calcitonin, parathyroid hormone) in fluids from FNA proved to be a very useful complementary diagnostic tool in such cases. The determination of endocrine markers in fluids other than serum/plasma has been developed in the last years. Although studies have reported overall satisfactory results, a good standardization of procedures has not yet been reached, and further efforts should be made in order to better define pre-analytical, analytical, and post-analytical aspects. Here we reviewed critically the literature on the measurement of FNA endocrine markers, focusing on laboratory issues, such as preparation of the sample, choice of solution, and technical features of determination of these markers. Indeed, information for use of FNA-Tg, FNA-CT, and FNA-PTH in clinical practice was also provided.

Routine calcitonin measurement in nodular thyroid disease management: is it worthwhile?

PURPOSE

To evaluate the diagnostic accuracy of routine calcitonin measurement in patients with nodular thyroid disease.

METHODS

Consecutive patients with nodular thyroid disease (n = 640) were studied. Serum calcitonin levels were measured under basal conditions, and when basal values were between 10-100 pg/mL, testing was repeated after pentagastrin (PG) stimulation. Patients with previously diagnosed or familial medullary thyroid cancer (MTC) were excluded. Patients were operated on when basal or stimulated calcitonin >100 pg/mL or when other surgical indications were present.

RESULTS

Four cases of MTC were identified. MTC was diagnosed in 75% of patients with basal calcitonin >100 pg/mL. One out of 11 patients with basal calcitonin between 10-100 pg/mL was diagnosed with MTC. PG stimulation resulted in elevation in 4 cases, where 1 case was diagnosed with MTC. Positive predictive value for basal calcitonin levels in the preoperative diagnosis of MTC was 5% for values between 10-100 pg/mL and 100% for values >100 pg/mL. Possible reasons for false positivity were papillary thyroid cancer in 17%, renal insufficiency in 8.3%, Hashimoto thyroiditis in 17% and β-blocker use in 33%. Positive predictive value for the PG test (>100 pg/mL) was 25% in the entire series. The cost of adding calcitonin measurement (±PG stimulation) to the preoperative work-up, resulted in €912.68 per MTC patient to detect the disease.

CONCLUSION

Basal calcitonin measurement together with PG stimulation in cases of basal calcitonin >10 pg/mL detects MTC in 0.62% of patients with nodular thyroid disease.

Analytical Performance of a Gene Expression Classifier for Medullary Thyroid Carcinoma

BACKGROUND

The aim of this study was to demonstrate the analytical validity of an RNA classifier for medullary thyroid carcinoma (MTC).

METHODS

Fresh-frozen tissue specimens were obtained from commercial sources, and MTC diagnoses were confirmed by histopathology review. De-identified patient fine-needle aspiration biopsies (FNABs) and whole blood from normal donors were obtained. Total RNA was extracted, amplified, and hybridized to custom microarrays for gene expression analysis. Gene expression data were normalized and classified via a machine learning algorithm. Positive control materials were produced from MTC tissues and tested across multiple experiments and laboratories. Twenty-seven MTC tissue specimens were used to evaluate the sensitivity of the MTC classifier. Gene expression data from tissues and FNABs were used to model classifier response to mixtures of MTC samples with normal thyroid tissue, a benign thyroid nodule, a Hürthle cell adenoma, and whole blood. Select mixture conditions were confirmed in vitro. Assay tolerance to RNA input variation (5-25 ng) and genomic DNA contamination (30% by mass) was evaluated. The intra- and inter-run reproducibility and inter-laboratory accuracy of MTC classifier results were characterized.

RESULTS

The MTC classifier sensitivity of 96.3% [confidence interval 81.0-99.9%] was determined retrospectively using 27 MTC confirmed tissue specimens. One false-negative result in a necrotic tissue implicated sample necrosis in reduced classifier sensitivity. Dilution modeling of MTC samples with normal or benign tissues showed consistent detection of MTC down to 20% sample proportions, with in vitro confirmation of 20% analytical sensitivity. Classifier tolerance to RNA input variation (5-25 ng), genomic DNA contamination (30% by mass), and an interfering substance (blood) was demonstrated with 100% accurate classifier results under all tested conditions. The maximum observed run-to-run score difference for a single FNAB sample was ∼1 unit compared with the average score difference between 38 MTC and non-MTC FNABs of ∼32 units. MTC classifier results for 20 tissues processed from total RNA in two different laboratories showed 100% concordance.

CONCLUSIONS

The MTC classifier, offered as part of the routine molecular testing of cytology-indeterminate thyroid nodules, demonstrates robust analytical sensitivity, specificity, accuracy, and reproducibility.

Arriving at the Right Diagnosis in an Era of Precision Medicine

In the era of precision medicine and targeted therapy, diagnostic inaccuracy can have tremendous ramifications. We present the case of a 61-year-old man initially diagnosed with small cell lung cancer by pathology. Prior to initiating chemotherapy, multidisciplinary discussions led to an amendment of the diagnosis to medullary thyroid cancer.

Reference values of serum calcitonin with calcium stimulation tests by electrochemiluminescence immunoassay before/after total thyroidectomy in Japanese patients with thyroid diseases other than medullary thyroid carcinoma

Calcitonin is a very sensitive tumor marker of medullary thyroid carcinoma (MTC). MTC patients usually have very high values of serum calcitonin that can be used to diagnose the disease. To improve the diagnostic sensitivity in family members with small MTCs and to evaluate the postoperative biochemical cure status, a calcium stimulation test is widely used. Serum calcitonin has been measured using several methods, but in Japan, only an electrochemiluminescence immunoassay (ECLIA) is currently performed to determine serum calcitonin. Reference values for the calcium stimulation test using an ECLIA have not been reported. Here we conducted a calcium stimulation tests in 26 patients without MTC before and after total thyroidectomy. Preoperatively, the basal calcitonin values of all patients were within normal limits and increased to a mean of 14.4 pg/mL after calcium stimulation. We transformed the peak values before total thyroidectomy to a logarithmic distribution and calculated the normalized mean ± 1.96× standard deviation; the reference upper limit was thus expressed. In the female patients with non-MTC, the reference upper limit was 67.6 pg/mL. In all patients, the calcium stimulation test results after total thyroidectomy showed undetectable basal and stimulated calcitonin values (<0.5 pg/mL). This is the first study to determine reference values to be used for the calcium stimulation test along with an ECLIA in non-MTC patients. We propose that female patients are regarded as biochemically cured or normal when the stimulated calcitonin values by ECLIA are <67.6 pg/mL before surgery and <0.5 pg/mL after total thyroidectomy.

Serum calcitonin negative medullary thyroid carcinoma: a systematic review of the literature

Generally, calcitonin (CT) values below the upper reference limit rule-out medullary thyroid carcinoma (MTC) with very high accuracy. However, sparse cases of serum-calcitonin-negative MTC (CT-NEG-MTC) have been reported. Here we reviewed CT-NEG-MTC reported in literature, discussed the potential causes and proposed a practical laboratory and clinical approach. A comprehensive literature search was conducted by using the terms "medullary thyroid carcinoma" AND "non-secreting calcitonin" OR "undetectable calcitonin". The search was updated until December 2014. Original articles that described CT-NEG-MTC were eligible for inclusion. Only MTC cases with preoperative CT below the upper reference limit were included in the present review. Eleven papers with 18 CT-NEG-MTC cases (age 50 years, size 26 mm) were retrieved. Four patients with poorly differentiated MTC died within 3 years. Different CT assays were employed and different reference values were adopted. Preoperative serum CT values were below the institution cut-off levels in all cases, and undetectable in four patients. In some papers negative CT results were confirmed by additional tests. Further laboratory investigations were performed in some of the included studies. In patients with well founded suspicious of MTC and within the reference limits/undetectable CT other laboratory investigations [carcinoembryonic antigen (CEA), procalcitonin, CT stimulation, CT in washout of nodule's aspiration] have to be performed. Surgical approach to CT-NEG-MTC does not differ from those secreting CT. Postoperative follow-up of these rare cases should include periodical imaging and measurement of all potential markers. Patients with poorly differentiated MTC are at higher risk of disease-related death, and require more aggressive follow-up strategy.

Retrospective analysis of 140 cases of medullary thyroid carcinoma followed-up in a single institution

Familial cases of medullary thyroid carcinoma (MTC) may be diagnosed by genetic screening, while in sporadic tumors the diagnosis relies mainly on fine-needle aspiration cytology. The aim of the present study was to determine the demographic, clinical and pathological characteristics of MTC patients followed-up at the Portuguese Institute of Oncology Francisco Gentil (Lisbon, Portugal). For that purpose, a retrospective analysis of 140 MTC patients diagnosed between 1990 and 2010 was performed. The results indicated that patients with hereditary MTC (11.4%) were significantly younger than patients with sporadic MTC. Of the latter, 34.3% had no clinical suspicion of MTC prior to surgery. The sensitivity of cytology and calcitonin (CT) assay in diagnosing MTC were 51.3 and 98.7%, respectively. All familial index cases and 69.0% of sporadic cases presented with advanced stage disease at the time of diagnosis, while 73.0% of familial MTC detected by genetic/pentagastrin screening were diagnosed at the early stage of the disease. Biochemical cure (BC) was achieved in 39.7% of patients and, of these, only 6.5% relapsed. The 5 and 10-year survival rates were 79.3 and 73.6%, respectively. Age >45 years (P=0.026), advanced stage at diagnosis (P<0.001) and absence of BC (P<0.001) were predictors of a worse prognosis on univariate analysis. However, when the patients detected by genetic/pentagastrin screening were excluded from the analysis, age was no longer a prognostic factor, although disease stage remained a significant prognostic factor. On multivariate analysis, BC was the only factor with a significant impact on prognosis (P=0.031). In addition, the present study confirmed that the majority of patients were diagnosed at advanced stages, and CT determination was observed to be more sensitive than cytology to diagnose MTC. Patients at early stages were more prone to achieve BC, which was a favorable prognostic factor. To the best of our knowledge, the present study reports for the first time that age at diagnosis is not a predictor of survival for patients with MTC when cases diagnosed by genetic/pentagastrin screening (who are usually young patients at the initial stages of the disease), are excluded from the analysis.

Epidemiology and Clinical Presentation of Medullary Thyroid Carcinoma

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor originating from the thyroid C cells producing mainly calcitonin (CTN) used as tumor marker. MTC occurs either sporadic (75%) or in a hereditary form (multiple endocrine neoplasia type 2, MEN2), due to germline mutations in the RET proto-oncogene. The discovery of an MTC in a patient has several diagnostic implications involving a specific strategy: preoperative evaluation of the tumor marker CTN and the extent of the disease, classification of MTC as sporadic or hereditary by DNA testing, and screening for associated endocrinopathies in hereditary MTC. Elevated CTN is a highly sensitive and specific tumor marker for diagnosis and follow-up of MTC. CTN is directly related to the tumor mass. In patients with nodular thyroid disease, diagnosis of MTC could be made by CTN determination as an indicator of tumor burden in conjunction with fine-needle aspiration. Patients with confirmed sporadic or hereditary MTC should have a total thyroidectomy and depending on the preoperative CTN value and the extent of disease additional dissection of the lymph nodes in the central and lateral neck compartment. In MEN 2 patients diagnosed by screening, the time of prophylactic thyroidectomy depends on RET mutation and CTN level.

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.

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.

The Role of Core Needle Biopsy and Its Impact on Surgical Management in Patients with Medullary Thyroid Cancer: Clinical Experience at 3 Medical Institutions

BACKGROUND AND PURPOSE

Medullary thyroid carcinoma is an uncommon malignancy that is challenging to diagnose. Our aim was to present our experience using core needle biopsy for the diagnosis of medullary thyroid carcinoma compared with fine-needle aspiration.

MATERIALS AND METHODS

Between January 2000 and March 2012, 202 thyroid nodules in 191 patients were diagnosed as medullary thyroid cancer by using sonography-guided fine-needle aspiration, core needle biopsy, or surgery. One hundred eighty-three thyroid nodules in 172 patients were included on the basis of the final diagnosis. We evaluated the sensitivity and positive predictive value of fine-needle aspiration and core needle biopsy for the diagnosis of medullary thyroid cancer. We compared the rate of a delayed diagnosis, a diagnostic surgery, and surgery with an incorrect diagnosis for fine-needle aspiration and core needle biopsy and investigated the factors related to the fine-needle aspiration misdiagnosis of medullary thyroid cancer.

RESULTS

Fine-needle aspiration showed 43.8% sensitivity and 85.1% positive predictive value for the diagnosis of medullary thyroid cancer; 25.7% (44/171) of patients had a delayed diagnosis, while 18.7% (32/171) underwent an operation for accurate diagnosis, and 20.5% (35/171) underwent an operation with an incorrect diagnosis. Core needle biopsy achieved 100% sensitivity and positive predictive value without a delay in diagnosis (0/22), the need for a diagnostic operation (0/22), or an operation for an incorrect diagnosis (0/22). A calcitonin level of <100 pg/mL was the only significant factor for predicting the fine-needle aspiration misdiagnosis of medullary thyroid cancer (P = .034).

CONCLUSIONS

Core needle biopsy showed a superior sensitivity and positive predictive value to fine-needle aspiration and could optimize the surgical management in patients with medullary thyroid cancer. Because the ability of fine-needle aspiration to diagnose medullary thyroid cancer significantly decreases in patients with serum calcitonin levels of <100 pg/mL, core needle biopsy could be indicated for these patients to optimize their surgical management.

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.

Diagnóstico, tratamento e seguimento do carcinoma medular de tireoide: recomendações do Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia

Introdução O carcinoma medular de tireoide (CMT) origina-se das células parafoliculares da tireoide e corresponde a 3-4% das neoplasias malignas da glândula. Aproximadamente 25% dos casos de CMT são hereditários e decorrentes de mutações ativadoras no proto-oncogene RET (REarranged during Transfection). O CMT é uma neoplasia de curso indolente, com taxas de sobrevida dependentes do estádio tumoral ao diagnóstico. Este artigo descreve diretrizes baseadas em evidências clínicas para o diagnóstico, tratamento e seguimento do CMT. Objetivo O presente consenso, elaborado por especialistas brasileiros e patrocinado pelo Departamento de Tireoide da Sociedade Brasileira de Endocrinologia e Metabologia, visa abordar o diagnóstico, tratamento e seguimento dos pacientes com CMT, de acordo com as evidências mais recentes da literatura. Materiais e métodos: Após estruturação das questões clínicas, foi realizada busca das evidências disponíveis na literatura, inicialmente na base de dados do MedLine-PubMed e posteriormente nas bases Embase e SciELO – Lilacs. A força das evidências, avaliada pelo sistema de classificação de Oxford, foi estabelecida a partir do desenho de estudo utilizado, considerando-se a melhor evidência disponível para cada questão. Resultados Foram definidas 11 questões sobre o diagnóstico, 8 sobre o tratamento cirúrgico e 13 questões abordando o seguimento do CMT, totalizando 32 recomendações. Como um todo, o artigo aborda o diagnóstico clínico e molecular, o tratamento cirúrgico inicial, o manejo pós-operatório e as opções terapêuticas para a doença metastática. Conclusões O diagnóstico de CMT deve ser suspeitado na presença de nódulo tireoidiano e história familiar de CMT e/ou associação com feocromocitoma, hiperparatireoidismo e/ou fenótipo sindrômico característico, como ganglioneuromatose e habitus marfanoides. A punção aspirativa por agulha fina do nódulo, a dosagem de calcitonina sérica e o exame anatomopatológico podem contribuir na confirmação do diagnóstico. A cirurgia é o único tratamento que oferece a possibilidade de cura. As opções de tratamento da doença metastática ainda são limitadas e restritas ao controle da doença. Uma avaliação pós-cirúrgica criteriosa para a identificação de doença residual ou recorrente é fundamental para definir o seguimento e a conduta terapêutica subsequente.

Usefulness of preoperative serum calcitonin in patients with nodular thyroid disease without suspicious history or cytology for medullary thyroid carcinoma

OBJECTIVE

To evaluate the usefulness of preoperative serum calcitonin (sCT) in patients with nodular disease without suspicion of medullary thyroid carcinoma (MTC) in history or cytology.

PATIENTS AND METHODS

sCT was measured before thyroidectomy in 494 patients with nodular disease who had no family history of MTC or multiple endocrine neoplasia type 2, and no cytological suspicion of MTC.

RESULTS

Basal sCT was < 10 ng/mL in 482 patients and none of them had MTC. One patient with basal sCT > 100 pg/mL had MTC. Among the 11 patients with basal sCT between 10 and 100 pg/mL, MTC was diagnosed in only one. The two patients with MTC were submitted to total thyroidectomy, combined with elective lymph node dissection indicated exclusively based on hypercalcitoninemia, and sCT was undetectable after six months.

CONCLUSIONS

Preoperative sCT is useful for the detection of sporadic MTC in patients with nodular disease, even in the absence of suspicious history or cytology.

Update on medullary thyroid cancer

Medullary thyroid carcinoma (MTC) is a rare type of thyroid cancer, demonstrating variable behavior from indolent disease to highly aggressive, progressive disease. There are distinguishing phenotypic features of sporadic and hereditary MTC. Activation or overexpression of cell surface receptors and up-regulation of intracellular signaling pathways in hereditary and sporadic MTC are involved in the disease pathogenesis. There has been an exponential rise in clinical trials with investigational agents, leading to approval of 2 medications for progressive, advanced MTC. Developments in understanding the pathogenesis of MTC will hopefully lead to more effective and less toxic treatments of this rare but difficult to treat cancer.

Comparison of serum calcitonin and procalcitonin in detecting medullary thyroid carcinoma among patients with thyroid nodules

BACKGROUND

To prospectively evaluate the role of procalcitonin (PCT) in detecting or excluding medullary thyroid carcinoma (MTC) among patients with thyroid nodules and increased calcitonin (CT) levels.

METHODS

Fourteen of 1236 patients referred for thyroid nodules had increased serum CT >10 pg/mL. A stimulation test with pentagastrin was done and both CT and PCT were measured after stimulation. All patients underwent thyroid ultrasound, fine-needle cytology and, if indicated, surgery with histological and immunohistochemical examination of the surgical specimens.

RESULTS

After follow-up, two MTCs were found. These two patients had basal CT >100 pg/mL and detectable (>0.1 ng/mL) PCT, with 100% sensitivity. Pentagastrin stimulated CT achieved values above 100 pg/mL in two MTCs and in other two cases with no MTC outcome (50% PPV and 83% NPV). On the contrary, all patients with no MTC had both basal and stimulated undetectable PCT (100% PPV and 100% NPV).

CONCLUSIONS

The addition of basal PCT measurement in patients with thyroid nodule(s) and increased CT may significantly improve accuracy of CT measurement without needing a PG stimulation test.