Clinical challenges with calcitonin-negative medullary thyroid carcinoma

Management of medullary thyroid cancer based on variation of carcinoembryonic antigen and calcitonin

Carcinoembryonic antigen (CEA) and calcitonin (Ctn) are pivotal biomarkers in the diagnosis and management of medullary thyroid carcinoma (MTC). However, their diagnostic reliability in perioperative period remains a topic of ongoing debate. This review synthesizes researches on perioperative fluctuations in CEA and Ctn levels, and evaluates the impact of their different combinations on MTC diagnosis, treatment decisions, and prognosis. Our findings highlight it is crucial to understand and interpret the various combinations of CEA and Ctn fluctuations within a clinical context. Furthermore, to reduce diagnostic errors and improve patient outcomes, we recommend follow-up diagnostic and treatment protocols designed to address the potential pitfalls associated with the use of these biomarkers.

Matrix Metalloproteinases 2 and 9 and Their Tissue Inhibitors in the Diagnostics of Medullary Thyroid Carcinoma

Medullary Thyroid Carcinoma (MTC) is a tumor of the neuroendocrine system. In recent years, the need to assess the MTC diagnostic-related parameters has emerged with the aim to elucidate the mechanisms involved in this pathology. The objective of this study was to evaluate the role of Matrix Metalloproteinases (MMPs) 2 and 9, their tissue inhibitors of matrix metalloproteinases (TIMPs), S100 protein, and amyloid in the diagnostic of MTC. Thirty-two samples with MTC (72% women) were included in this cross-sectional study and divided by groups: T category 1 (T1)≤20 mm and T category 2 (T2) 20 to 40 mm of tumor size. MMPs 2 and 9, TIMPs 2 and 1, S100 protein, and calcitonin in tissues were obtained by immunohistochemical techniques. The presence of amyloid in tissue sections was detected on Thioflavin T-stained slides under fluorescent microscope. Percentage of positive cells (P) observed for MMP-2 was higher in those samples presenting T2 MTC with respect to those with T1 MTC ( P <0.05). Moreover, P-MMP-2 showed a direct correlation with higher T category of MTC (Rho=0.439, P  < 0.001), whereas P-MPP-9 was directly correlated with S100 protein and the intensity of calcitonin in tissues (Rho=0.419, P =0.017; Rho=0.422, P =0.016, respectively. Therefore, MMPs were directly correlated with some traditional biomarkers of MTC. In this regard, P-MMP-2 was more expressed in type 2 MTC. Combining the analysis of traditional and other useful biomarkers of MTC as MMPs 2 and 9 could be a useful strategy in the diagnostic of MTC.

Case Report: A Challenging Clinical Problem of Calcitonin-Negative Medullary Thyroid Cancer Diagnosis and Surveillance

Medullary carcinoma of the thyroid is a rare neuroendocrine carcinoma that originates from the malignant proliferation of parafollicular C cells. In almost 100% of the cases, medullary carcinoma of the thyroid is associated with high levels of calcitonin and carcinoembryonic acid (CEA). Both carcinoembryonic antigen and calcitonin are used for the diagnosis and surveillance of medullary carcinoma of the thyroid. Calcitonin-negative medullary carcinoma of the thyroid is an extremely rare entity that is characterized by classic medullary carcinoma of the thyroid morphology without raised serum calcitonin levels. We describe the case of a middle-aged lady who presented with a few-month history of neck swelling associated with compressive symptoms. CT of the neck showed a large right thyroid nodule with central necrosis and retrosternal extension to the superior mediastinum. There was also a 360-degree encasement of the right common carotid artery. She underwent fine needle aspiration (FNAC) of the right thyroid nodule, and histopathology showed typical features of medullary carcinoma of the thyroid. Immunohistochemical staining for calcitonin and carcinoembryonic antigen was negative but positive for other neuroendocrine markers, i.e., synaptophysin and chromogranin A. Serum calcitonin and carcinoembryonic antigen levels were also in the normal range. So, a rare diagnosis of calcitonin-negative medullary carcinoma of the thyroid was made. As the disease was inoperable because of vascular encasement, a plan for external beam radiation therapy (ERBT) to the neck was made. Medullary carcinoma of the thyroid with normal serum levels of calcitonin is a very rare entity, with only a few cases reported in the literature. In this case report, we have presented a rare case of medullary thyroid carcinoma (MTC) with normal-range serum calcitonin levels, how it was diagnosed, and how to follow up postoperatively.

Analytical Performance Evaluation of a New Calcitonin Assay

BACKGROUND

The use of efficient laboratory calcitonin (CT) testing is required for optimal management of medullary thyroid carcinoma. Several pitfalls are related to the calcitonin laboratory assays and a careful evaluation is needed. We report the analytical performances of the new Siemens ADVIA-Centaur-CALCT (CT-XPT) assay and its comparison with our standard method DiaSorin-Calcitonin-II-Gen (CT-LIA) assay.

METHODS

Analytical performance of the CT-XPT-assay, limit of blank (LOB), limit of detection (LOD), and limit of quantification (LOQ), were determined. We also evaluated the in vitro stability of the sample, together with the linearity and percentage recovery.

RESULTS

The CT-XPT-assay showed a better detection limit than the CT-LIA assay, with lower values of LOB (0.86 pg/mL vs 1.00 pg/mL) and LOQ (1.65 pg/mL vs 3.00 pg/mL). Both values were in agreement with those reported by the manufacturer. Within- and between-run precision demonstrated a good concordance of results. Regarding the in vitro stability of CT, the low CT concentration sera showed a much greater decrease in CT levels compared to the high concentration sera. Correlation studies showed a good correlation between the two methods (Kappa Cohen coefficent, KC: 0.68, agreement % for male: 89.58%; KC: 0.63; agreement % for female: 88.33%).

CONCLUSIONS

Our findings showed a good correlation between the CT-LIA and CT-XPT methods. Moreover, we demonstrated that the analytical performance of the CT-XPT assay, together with its technical specifications, could represent major features of the CT-XPT method. Collectively, the technical evaluation and the analytical results described in the presented paper highlight that the novel CT-XPT is a valid method for CT testing in a clinical diagnostic setting.

Oncologic outcomes of calcitonin-negative medullary thyroid carcinoma

OBJECTIVE

Calcitonin (Ct)-negative medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor. This study aimed to clarify its incidence, clinicopathologic characteristics, management, and treatment outcome.

METHODS

We retrospectively analyzed data of patients with primary MTC. Patients were divided into two groups according to the preoperative serum Ct level (Ct-negative and Ct-positive). The demographic, pathologic, and molecular characteristics, and treatment outcomes were compared between the two groups. In the Ct-negative group, we analyzed the association between the operation type and treatment outcome.

RESULTS

Of the total 312 patients, 24 were diagnosed with Ct-negative MTC. The rate of lymph node metastasis was significantly higher in the Ct-positive than in the Ct-negative group (47.9% vs. 0%, p<0.001). The proportion of patients with Ki-67 ≤10% was significantly higher in the Ct-negative than in the Ct-positive group (87.5% vs. 38.2%, p<0.001). Excellent response was achieved by 91.7% and 34.7% of patients in the Ct-negative and Ct-positive groups, respectively (p<0.001). In the Ct-negative group, excellent response was achieved by all female patients, but only 50% of male patients.

CONCLUSIONS

Ct-negative MTC is rare and unlikely to develop lymph node metastasis. Unilateral lobectomy tends to provide a satisfactory chance of excellent response; however, this requires further validation.

Feasibility of lateral sentinel lymph node biopsy in medullary thyroid cancer: A surrogate tool for determining prophylactic lateral neck dissection-A pilot study

BACKGROUNDS

This study aimed to evaluate usefulness of lateral sentinel lymph node biopsy (SLNB) in determining lateral neck dissection (LND) of patients with medullary thyroid cancer (MTC).

METHODS

Sixteen patients with MTC were enrolled in the study from January 2013 to June 2019. Intratumoral injection of technetium (Tc)-99m phytate followed by lymphoscintigraphy was performed preoperatively. Lateral sentinel lymph nodes were detected by a collimated gamma probe and underwent frozen analysis. Ipsilateral LND was performed in all patients to assess lateral LN status.

RESULTS

The identification rate of sentinel lymph nodes (SLNs) detected by radioisotope was 87.5% (14 of 16 patients). The sensitivity, specificity, positive predictive value, and negative predictive value of frozen analyses were 66.7%, 100%, 100%, and 91.6%, respectively. Based on final histopathology, however, the diagnostic values of lateral SLNB were all 100%.

CONCLUSIONS

This study showed that lateral SLNB can be a promising surgical tool for decisions on LND in patients with MTC.

Calcitonin-Negative Neuroendocrine Carcinoma of the Thyroid Gland: Case Report and Literature Review

Calcitonin-negative neuroendocrine tumor (CNNET) of the thyroid is an extremely rare entity. In some of the previously reported cases within the literature, the terms “atypical medullary thyroid carcinoma,” “calcitonin-free oat cell carcinoma,” and “a distinct clinical entity” were applied to NETs without definitive evidence of calcitonin production. In the English-language literature, not only are there only few reported cases of CNNET, but the criteria for diagnosis in these cases are also controversial. Most of the current published cases were also treated surgically for local disease. We describe a case of NET of the thyroid with calcitonin, chromogranin A and thyroglobulin negativity, synaptophysin and TTF-1 positivity, and a high Ki-67 proliferation index with metastases in the cervical region as well as mediastinal adenopathies. This case was considered an unresectable thyroid carcinoma, and chemotherapy including cisplatin and etoposide was started as neoadjuvant treatment at the department of medical oncology. Total thyroidectomy plus bilateral and central cervical dissection was performed, and the patient underwent 2 cycles of adjuvant radiotherapy. Currently, the patient's ¹⁸F-FDG-PET/CT findings show a complete response 17 months after diagnosis. In conclusion, CNNET of the thyroid is very rare and there is limited evidence regarding treatment in patients with metastases. Chemotherapy including cisplatin and etoposide as well as early aggressive surgical resection appears to positively impact patients' survival.

Medullary Thyroid Carcinoma With Elevated Serum CEA and Normal Serum Calcitonin After Surgery: A Case Report and Literature Review

Background

Medullary thyroid carcinoma (MTC) is a relatively rare malignant tumor subtype originated the parafollicular C cells of the thyroid gland, producing tumor markers including calcitonin (Ctn), carcinoembryonic antigen (CEA), and chromogranin A. Preoperative serum Ctn and CEA value is important for assessing disease burden, postoperative serum Ctn and CEA can help to determine whether there are recurrence and distant metastasis.

Case Presentation

We report a rare case in which the CEA level continued to increase and the Ctn value was normal after total thyroidectomy and central lymph node dissection in a MTC patient. The patient was asymptomatic during one and half year follow-up until lateral lymph node metastasis was revealed. However, the CEA level raised again after lateral neck lymph node dissection and bone metastases were found by 18F-FDG PET-CT.

Conclusion

This case reminded us the recurrence of MTC should be suspected for patients with simply elevated CEA after surgery for MTC. Differential diagnosis of other malignant tumors and timely lymph node biopsy is of great significance for management.

Characterization of "suspicious for malignancy" for non-papillary carcinoma diagnoses on thyroid fine-needle aspiration

INTRODUCTION

To evaluate the incidence, risk of malignancy, and management of "suspicious for malignancy" (SFM) for non-papillary carcinoma diagnoses according to The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC).

MATERIALS AND METHODS

A retrospective search was performed for all thyroid fine-needle aspirations (FNAs) with an SFM diagnosis in the electronic Pathology database at The Johns Hopkins Hospital from 2000 to 2019. During this period, a total of 644 cases were diagnosed as SFM. Of these, 55 cases of "suspicious for non-papillary thyroid carcinoma" (SNPTC) were identified. These 55 cases were then compared with 65 random cases of "suspicious for papillary thyroid carcinomas" (SPTC) diagnoses as a control group.

RESULTS

The SNPTC subgroup consisted of 28 cases of "suspicious for medullary thyroid carcinoma" (SMTC) (50.91%), 4 cases of "suspicious for metastasis" (SMET) (7.27%), 3 cases of "suspicious for malignant lymphoma" (SML) (5.45%), 2 cases of "suspicious for poorly-differentiated thyroid carcinoma" (SPDC) (3.64%), and 18 cases of "suspicious for malignancy, not otherwise specified" (SNOS) (32.73%). When compared to SPTC, SNPTC patients' average age was older (P = 0.004). Ancillary studies assisted in diagnosing SNPTC more so than SPTC (P < 0.001). Immunohistochemical studies were performed for 11 cases, molecular studies for 6 cases, and needle rinse calcitonin level for 1 case. When correlated with surgical follow-ups, the risk of malignancy (ROM) was 91.18% for SNPTC compared to 93.75 for SPTC%.

CONCLUSIONS

SNPTC was rarely diagnosed when compared with SPTC. SMTC was the most commonly diagnosed SNPTC subgroup, followed by SNOS. The ROM of SNPTC was slightly lower than that of SPTC. Ancillary studies and previous clinical history, in addition to cytomorphology, was helpful when rendering the diagnosis of SNPTC.

Paraganglioma-like medullary thyroid carcinoma: A case report and literature review

Medullary thyroid carcinoma (MTC) accounts for 3%-5% of all thyroid malignancies. Most MTC can be diagnosed by their typical cytologic and histologic morphology and immunohistochemical features. However, some rare variants of MTC may pose diagnostic difficulties on both cytology and histology. Paraganglioma-like MTC (PLMTC) is a rare, but widely recognized variant of MTC. PLMTC is known to share morphological and architectural similarities with paraganglioma, hyalinizing trabecular tumor, and carcinomas of thyroid follicular cell origin, such as follicular carcinoma and follicular variant of papillary thyroid carcinoma. The combination of clinicopathologic features and a battery of immunohistochemical markers is essential for making a correct diagnosis. Herein, we report one case of PLMTC with both cytologic and histologic features and review the clinicopathologic features of previously reported cases.

Calcitonin-negative neuroendocrine tumor of the thyroid with metastasis to liver-rare presentation of an unusual tumor: A case report and review of literature

BACKGROUND

Neuroendocrine tumors mainly occur in the stomach, intestine, pancreas, and lung and are rarely detected in the thyroid. Thyroid neuroendocrine tumors, designated medullary thyroid carcinoma, generally present with elevated calcitonin. Calcitonin-negative neuroendocrine tumors of the thyroid are extremely rare.

CASE SUMMARY

Here, we present a case report of a 56-year-old female patient with a neck pain complaint. Total thyroidectomy was conducted after comprehensive evaluation, and diagnosis was confirmed as calcitonin-negative neuroendocrine tumor of the thyroid. Two months later, liver metastasis was detected, and transcatheter arterial chemoembolization was subsequently performed to control growth. However, the curative effect was unsatisfactory and multiple intrahepatic metastases occurred after 3 mo.

CONCLUSION

Owing to the rarity of this disease, no clear guidelines are available for treatment. In addition to reporting this rare case, we have reviewed and summarized associated medical literature with an aim to provide a comprehensive reference platform for subsequent research.

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.

CALCITONIN REVISITED IN 2020

Calcitonin (CT) is a polypeptidic hormone specifically secreted by the thyroid parafollicular cells (C cells) and tangentially involved in human phosphocalcic and bone metabolism. CT from other species (e.g. salmon) is more potent than human CT and has limited therapeutic applications. The neoplastic proliferation of C cells leads to medullary thyroid carcinoma (MTC) generally characterized by an increase of CT secretion. Serum CT is therefore the ideal marker for MTC and can confirm its presence at an early stage, as well as the follow up of its remission or progression/relapse/survival after surgery. There are, however, controversies such as the necessity of CT screening in patients with thyroid nodules, or particular situations causing false positive or false negative results. Our minireview also deals with an up-to-date of surgical procedures for MTC, as well as with non-surgical therapy.

Genetic analysis of a hereditary medullary thyroid carcinoma case with normal preoperative serum calcitonin levels

CONTEXT

Serum calcitonin is often elevated in medulla thyroid carcinoma (MTC) and thus serves as an indicator of primary and recurrent disease. However, there are MTC patients with normal Serum calcitonin and the underlying mechanisms are largely unknown.

CASE DESCRIPTION

A 48-year-old female patient presenting with a right anterior cervical mass was diagnosed with medullary carcinoma. She had elevated carcinoembryonic antigen (CEA) but normal Serum calcitonin levels. Next generation sequencing (NGS) of paired tumor and peripheral blood revealed a germline pathogenic RET mutation, indicating the hereditary nature of MTC in this patient. Two somatic loss-of-function mutations in DICER1 gene were also found, which we postulated to account for the normal calcitonin levels found in this patient. To our knowledge, this is the first report of a hereditary MTC case displaying a normal Serum calcitonin.

CONCLUSIONS

The case suggests NGS can be used in the diagnosis of hereditary MTC and exploring the reasons of normal Serum calcitonin in these patients.

Calcitonin negative Medullary Thyroid Carcinoma: a challenging diagnosis or a medical dilemma?

BACKGROUND

Medullary thyroid carcinoma is a neuroendocrine tumor belonging form a malignant growth of the thyroid parafollicular C-cells, representing from 1 to 10% of all thyroid cancer. The biochemical activity of medullary thyroid carcinoma includes the production of calcitonin and carcinoembryogenic antigen, which are sensitive tumor markers, facilitating the diagnosis, follow-up and prognostication. The diagnosis is reached through the identification of high basal calcitonin serum level or after pentagastrin stimulation test. Medullary thyroid carcinoma is able to produce other relevant biomarkers as procalcitonin, carcinoembryionic antigen and chromogranin A. In Literature are described few cases of medullary thyroid carcinoma without elevation of serum calcitonin, an extremely rare event. The aim of this study was to analyse the presentation, the main features and therapeutic management of medullary thyroid carcinoma associated with negative serum calcitonin levels.

METHODS

Using the PubMed database, a systematic review of the current Literature was carried out, up to February 2018. Finally, nineteen articles met our inclusion criteria and were selected according to the modified Newcastle-Ottawa scale.

RESULTS

Fourty-nine patients with definitive pathology confirming medullary thyroid carcinoma and with calcitonin serum level in the normal range were identified (24 female, 24 male and not reported gender in 1 case). Mean age was 51.7 years. Serum calcitonin levels were reported for 20 patients with a mean value of 8.66 pg/mL and a range of 0.8-38 pg/mL. Despite the low or undetectable calcitonin serum level, at immunochemistry in almost the half of the cases reported by the Authors, the tumors presented diffuse or focal positivity for calcitonin and carcinoembryionic antigen, while was reported a chromogranin A positivity in 41 of the 43 tested patients.

CONCLUSIONS

Calcitonin negative medullary thyroid carcinoma is an extremely rare pathology. The diagnosis and the surveillance is often challenging and delayed, due to the lack of elevation of serum markers as calcitonin and carcinoembryionic antigen. Further studies are needed, to better define options for management of non secretory medullary thyroid carcinoma and to identify new and reliable biomarkers associated to diagnosis and relapse of this medical dilemma.

Case report of a neuroendocrine tumor of the thyroid gland with limited calcitonin expression: a diagnostic challenge

Medullary thyroid carcinoma (MTC) is a malignant tumor of the parafollicular cells, which produce calcitonin. As a result, calcitonin is an important tool for diagnosing MTC. When there is focal or no calcitonin staining, diagnosis of MTC can be challenging as this may suggest differences in cell origin and in prognosis and recurrence of the disease. The prognosis and guidelines for management and follow up for MTC remain inconclusive. Here, we present a case of primary neuroendocrine tumor of the thyroid gland with only focal calcitonin staining on immunohistochemistry and low serum calcitonin level despite a tumor size of almost 4 cm. The assumption of C-cell origin was made from positive staining for carcinoembryonic agent (CEA), thyroid transcription factor 1 (TTF-1) and paired box 8 (PAX8) without expression of thyroglobulin (Tg). The patient underwent thyroid lobectomy and follow-up monitoring with ultrasound and measurements of calcitonin and CEA levels, without any further surgical intervention. Few cases of neuroendocrine tumors with limited calcitonin expression have been published and the etiology and prognosis are still unknown. Our case suggests that limited calcitonin expression cannot completely exclude the diagnosis of MTC. This rare type of MTC should be differentiated from the typical presentation of MTC. Treatment and post-operative surveillance should be tailored based on the individual.

Metastases to the Thyroid: Potential Cytologic Mimics of Primary Thyroid Neoplasms

Secondary tumors of the thyroid gland, although uncommon, can sometimes pose as diagnostic dilemmas on fine-needle aspiration cytology, frequently mimicking primary thyroid neoplasms. An accurate diagnosis of such lesions, however, is critical for patient management and prognosis. The present study reviews the cytologic aspects of secondary involvement of the thyroid, listing the most common primary malignancies that metastasize to this gland. Knowledge of such morphologic aspects, combined with prompt clinical correlation, is essential for the cytopathologist to achieve a proper, definite diagnosis.

Refractory thyroid carcinoma: which systemic treatment to use?

The incidence of thyroid cancer has increased markedly in recent decades, but has been stable in terms of mortality rates. For the most part, these cancers are treated with surgery, which may or may not be followed by radioactive iodine depending on the tumor subtype. Still, many of these cancers will recur and may be treated with radioactive iodine or another surgery. It is unclear what treatment is best for cases of locally advanced or metastatic thyroid cancer that are refractory to radioactive iodine. Chemotherapy has a very low response rate. However, in the past few years, several systemic therapies, primarily targeted, have emerged to improve the overall survival of these patients. Alternative treatments are also of interest, namely peptide receptor radionuclide therapy or immunotherapy.

Plasma Calcitonin Levels and miRNA323 Expression in Medullary Thyroid Carcinoma Patients with or without RET Mutation

Background: Medullary thyroid cancer (MTC) is an endocrine tumor featuring parafollicular or C-cell differentiation, with calcitonin as a specific biomarker in MTC diagnosis. Germline mutations in the RET proto-oncogene are considered responsible for its familial occurrence and somatic mutations can cause sporadic lesions. MicroRNAs can act as oncogenes or tumor suppressors by inhibiting the expression of target genes.. The aim of this study was to investigate relationships between plasma levels of calcitonin and miRNA323 expression in MTC patients with or without RET mutation. Methods: In this cross-sectional study, MTC lesions (based on pathological confirmation) were investigated. Genomic DNA was extracted and Exons 10 and 11 of RET were genotyped using PCR-sequencing. Division was into two groups of 43 cases each with or without mutation. Plasma levels of calcitonin were determined in both. Results: miRNA323 was measured using real-time-PCR. After performing normality tests, independent T-tests and Mann Whitney tests were used for the statistical comparison of parametric and nonparametric data, respectively. Plasma levels of calcitonin were significantly higher in MTC cases without a RET mutation compared to those with a mutation. Conclusion: There was no significant difference between the two groups regarding the expression of miRNA323 so that this parameter could not be used as a bio-index germ line mutations in MTCs. However, determination of calcitonin levels in plasma might be helpful in this regard.