Hürthle cell carcinoma: current perspectives

Thyroid Cancer Prevalence, Risk Exposure, and Clinical Features Among Transgender Female Veterans

Purpose

Transgender women experience higher-than-average rates of multiple medical conditions. Thyroid cancer occurs more frequently in those assigned female at birth than in those assigned male at birth. We sought to characterize thyroid cancer among transgender female veterans.

Methods

We reviewed charts of veterans who were (1) seen in Veterans Affairs clinics across the United States from July 2017 to December 2022, (2) had an International Classification of Diseases, revision 10, diagnosis code for thyroid cancer, and (3) had an International Classification of Diseases, revision 10, diagnosis code for gender dysphoria or were assigned male at birth and ever had a prescription for estrogens. Charts of cisgender veterans were also reviewed for comparison.

Results

Compared with calculated estimates of 0.641% (95% CI, 0.572-0.724) among cisgender females and 0.187% (95% CI, 0.156-0.219) among cisgender males, the measured prevalence among transgender female veterans was 0.341% (34/9988). Average age at thyroid cancer diagnosis in this population was 53.8 (± SEM 2.61) years. A total of 32.3% (11/34) of these patients had extrathyroidal disease at diagnosis.

Discussion

To our knowledge, this study represents the first report of thyroid cancer prevalence among transgender women in the United States. Risk exposure among all transgender veterans including further assessment of the possible contributions of obesity, smoking, and gender-affirming hormone therapy are important future analyses.

Megaprosthesis for a Rare Case of Bone Metastasis of Thyroid Carcinoma: Case Management and Surgical Approach

We present the case of a 56-year-old male patient diagnosed with Hürthle cell carcinoma (HCC) that developed widespread metastasis in bone, lung, and lymph nodes with a larger tumor located in the right tibia. The patient was only disturbed by the pain, discomfort, and disability linked to the tibial metastasis. After careful consideration, the best course of action was considered to be the surgical excision of the proximal right tibia with arthroplasty using the C LINK Megaprosthesis tumor revision system. Histological and immunohistochemical analyses were conducted on the tibial resection specimen. In addition, a comprehensive review of prior histological specimens from the primary thyroid tumor, lymph nodes, and lung was undertaken to evaluate the prognosis and provide guidance for the postoperative management of the patient.

Diagnostic performance of molecular testing in indeterminate (Bethesda III and IV) thyroid nodules with Hürthle cell cytology

BACKGROUND

Indeterminate thyroid nodules with Hürthle cell cytology remain a diagnostic challenge. The low benign call rate and positive predictive value of first-generation molecular tests precluded their use to rule out malignancy. We examined the diagnostic performance of current tests.

METHOD

This subset analysis of our prospective randomized trial compared the benign call rate and positive predictive value of Afirma Gene Sequencing Classifier and Thyroseq v3 in Bethesda III and IV nodules with Hürthle cell cytology. Molecular test samples were obtained at initial fine-needle aspiration (8/2017-7/2022) and reflexively sent for processing.

RESULTS

Molecular testing was performed on 140 Hürthle cell nodules. Of 79 nodules tested with the Afirma Gene Sequencing Classifier, the benign call rate was 84% (66/79). Nine of 66 nodules with benign results were resected, with no malignancies. Twelve of 13 nodules with suspicious results were resected, revealing 3 malignancies-2 papillary thyroid carcinomas and one Hürthle cell carcinoma (positive predictive value 25%). Of 61 nodules tested with Thyroseq v3, the benign call rate was 56% (34/61; (P < .01 versus Afirma Gene Sequencing Classifier). Five of 34 nodules with negative results were resected, with no malignancies. Nineteen of 27 nodules with positive results were resected, revealing 3 malignancies-2 papillary thyroid carcinomas and 1 Hürthle cell carcinoma (positive predictive value 16%).

CONCLUSION

The high benign call rate of current molecular tests in Hürthle cell nodules strengthens their value in enabling patients to avoid surgery.

Somatostatin Receptor Type 2 and Thyroid-Stimulating Hormone Receptor Expression in Oncocytic Thyroid Neoplasms: Implications for Prognosis and Treatment

Somatostatin receptor type 2 (SSTR2) and thyroid-stimulating hormone receptor (TSHR) display variable expression in primary thyroid tumors and have been implicated as theranostic targets. This study was designed to explore the differential expression of SSTR2 and TSHR in oncocytic (Hurthle cell) carcinoma (OC) vs oncocytic adenoma (OA). We performed a retrospective review for oncocytic neoplasms treated at our institution from 2012 to 2019. Formalin-fixed paraffin-embedded tissue blocks were used for tissue microarray construction. Tissue microarray blocks were cut into 5-μm sections and stained with anti-SSTR2 and anti-TSHR antibodies. Immunostains were analyzed by 3 independent pathologists. χ2 and logistic regression analysis were used to analyze clinical and pathologic variables. Sixty-seven specimens were analyzed with 15 OA and 52 OC. The mean age was 57 years, 61.2% were women, and 70% were White. SSTR2 positivity was noted in 2 OA (13%) and 15 OC (28%; 10 primary, 4 recurrent, and 1 metastatic) (P = .22). TSHR positivity was noted in 11 OA (73%) and 32 OC (62%; 31 primary and 1 metastatic) (P = .40). Those who presented with or developed clinical recurrence/metastasis were more likely to be SSTR2-positive (50% vs 21%; P = .04) and TSHR-negative (64.3% vs 28.9%; P = .02) than primary OC patients. Widely invasive OC was more likely to be SSTR2-positive compared to all other OC subtypes (minimally invasive and angioinvasive) (P = .003). For all patients with OC, TSHR positivity was inversely correlated with SSTR2 positivity (odds ratio, 0.12; CI, 0.03-0.43; P = .006). This relationship was not seen in the patients with OA (odds ratio, 0.30; CI, 0.01-9.14; P = .440). Our results show that recurrent/metastatic OC was more likely to be SSTR2-positive and TSHR-negative than primary OC. Patients with OC displayed a significant inverse relationship between SSTR2 and TSHR expression that was not seen in patients with OA. This may be a key relationship that can be used to prognosticate and treat OCs.

Thyroid collision tumour with pulmonary metastases treated effectively with nedaplatin and paclitaxel chemotherapy: A case report

Collision tumour of the thyroid is a rare entity for which surgical resection is the primary treatment. We present here a case of a collision thyroid tumour of oncocytic and papillary carcinoma with lung metastases occurring in a 62-year-old woman who initially presented with a rapidly enlarging cervical mass and dyspnoea. The patient had extensive venous tumour thrombosis in the internal jugular and subclavian veins. The patient received six cycles of combined chemotherapy with nedaplatin and paclitaxel which significantly reduced the size of the metastases in the lungs. Following discharge from the hospital, the patient was treated with oral anlotinib and at 14 months follow up she had not experienced any serious side effects and the metastases in her lung and thyroid surgery areas were well controlled.

Surgical management of metastatic Hürthle cell carcinoma to the skull base, cortex, and spine: illustrative case

BACKGROUND

Hürthle cell carcinoma (HCC) is an unusual and aggressive variant of the follicular type of differentiated thyroid cancer (DTC), accounting for less than 3% of DTCs but posing the highest risk of metastasis. Brain metastases are uncommonly reported in the literature but pose a poor prognosis. The low rate of brain metastases from HCC coupled with ambiguous treatment protocols for the extracranial disease complicate successful disease management and definitive treatment strategy. The authors present the case of a patient with HCC metastasis to the skull base, cortex, and spine with recent tibial metastasis.

OBSERVATIONS

Despite the presence of metastasis to the cortex, skull base, and spine, the patient responded very well to radiation therapy, sellar mass resection, and cervical spine decompression and fixation and has made a remarkable recovery.

LESSONS

The authors' multidisciplinary approach to the patient's care, including a diverse team of specialists from oncology, neurosurgery, orthopedic surgery, radiology, endocrinology, and collaboration with clinical trial researchers, was fundamental to her successful outcome, demonstrating the utility of intersecting specialties in successful outcomes in neuro-oncological patient care.

Multi-Omics and Management of Follicular Carcinoma of the Thyroid

Follicular thyroid carcinoma (FTC) is the second most common cancer of the thyroid gland, accounting for up to 20% of all primary malignant tumors in iodine-replete areas. The diagnostic work-up, staging, risk stratification, management, and follow-up strategies in patients who have FTC are modeled after those of papillary thyroid carcinoma (PTC), even though FTC is more aggressive. FTC has a greater propensity for haematogenous metastasis than PTC. Furthermore, FTC is a phenotypically and genotypically heterogeneous disease. The diagnosis and identification of markers of an aggressive FTC depend on the expertise and thoroughness of pathologists during histopathological analysis. An untreated or metastatic FTC is likely to de-differentiate and become poorly differentiated or undifferentiated and resistant to standard treatment. While thyroid lobectomy is adequate for the treatment of selected patients who have low-risk FTC, it is not advisable for patients whose tumor is larger than 4 cm in diameter or has extensive extra-thyroidal extension. Lobectomy is also not adequate for tumors that have aggressive mutations. Although the prognosis for over 80% of PTC and FTC is good, nearly 20% of the tumors behave aggressively. The introduction of radiomics, pathomics, genomics, transcriptomics, metabolomics, and liquid biopsy have led to improvements in the understanding of tumorigenesis, progression, treatment response, and prognostication of thyroid cancer. The article reviews the challenges that are encountered during the diagnostic work-up, staging, risk stratification, management, and follow-up of patients who have FTC. How the application of multi-omics can strengthen decision-making during the management of follicular carcinoma is also discussed.

Lenvatinib as a Promising Treatment Option for Unresectable Hürthle Cell Carcinoma: A Case Report

Hürthle cell carcinoma (HCC) of the thyroid gland generally has a more aggressive clinical course than other differentiated thyroid cancers (DTCs), and it is associated with a higher rate of distant metastases. In this case report, we highlight the importance of tyrosine kinase inhibitors as a management strategy for unresectable DTCs. Surgical management is challenging if the cancer is locally advanced and invades major neck structures with an increased risk of recurrence. Tyrosine kinase inhibitors (TKIs) are used in the case of advanced disease, especially in unresectable, radio-iodine refractory and with metastatic status. Lenvatinib, a TKI, used as the first line of treatment, plays a key role in improving prognosis and survival rates among patients. A 37-year-old gentleman presented with a locally advanced and widely metastasized case of large Hürthle cell carcinoma encasing the left carotid sheath and the left recurrent laryngeal nerve. Fine needle aspiration cytology (FNAC) was suggestive of HCC and a positron emission tomography-computed tomography (PET-CT) scan revealed metastases to the lungs and spine. In this case, lenvatinib was used to prevent the proliferation of malignant cells and the neovascularization of the tumor. This clinically translated into a good response in a high disease burden scenario. The patient showed positive results with lenvatinib therapy with a progression-free duration of 30 months and a reduction in the size of cancer. This case report describes the use of lenvatinib for the treatment of a large unresectable locally advanced and widely metastasized case of Hürthle cell carcinoma in a young gentleman with a response profile.

Outcomes and Trends of Treatments in High-Risk Differentiated Thyroid Cancer

OBJECTIVES

To analyze the variant-specific survival benefits and usage patterns of standardized treatment combinations of surgery (S), radioactive iodine ablation (RAI), and thyroid-stimulating hormone suppression therapy (THST) for high-risk differentiated thyroid cancer.

STUDY DESIGN

Retrospective cohort study.

SETTING

National Cancer Database.

METHODS

The 2004-2017 National Cancer Database was queried for patients receiving definitive surgery for high-risk papillary, follicular, or Hurthle cell thyroid cancer. Cox proportional hazards and Kaplan-Meier analyses assessed for treatment-associated survival.

RESULTS

Of 21,076 cases, 18,214 underwent survival analysis with a mean ± SD age of 50.6 ± 17.1 years (71.3% female). When compared with surgery alone, S + RAI was associated with reduced mortality in papillary (hazard ratio [HR], 0.574; P < .001) and follicular (HR, 0.489; P = .004) thyroid cancer. S + RAI + THST was associated with reduced mortality in papillary (HR, 0.514; P < .001), follicular (HR, 0.602; P = .016), and Hurthle cell (HR, 0.504; P = .021) thyroid cancer. In papillary thyroid cancer, S + RAI (91.3%), S + THST (89.2%), and S + RAI + THST (92.7%) were associated with higher 5-year overall survival rates than surgery (85.4%, all P < .001). Papillary thyroid cancer treatments involving THST were associated with higher 5-year overall survival rates than corresponding regimens without THST (all P < .001). In follicular thyroid cancer, S + RAI (73.9%) and S + RAI + THST (78.7%) were associated with higher 5-year overall survival rates than surgery (65.6%, all P < .05). In Hurthle cell thyroid cancer, S + RAI (66.5%) and S + RAI + THST (73.4%) were associated with higher 5-year overall survival rates than surgery (53.7%, all P < .05). On linear regression, THST usage increased by 77.5% (R² = 0.944, P < .001), while RAI usage declined by 11.3% (R² = 0.320, P = .035).

CONCLUSIONS

High-risk differentiated thyroid cancer exhibited varying susceptibilities to different treatment combinations depending on histology, with greatest responses to regimens that included RAI. Physician practices have trended toward decreased RAI and increased THST usage.

Role and Extent of Neck Dissection for Neck Lymph Node Metastases in Differentiated Thyroid Cancers

Differentiated thyroid cancers (DTC) consist of 95% of thyroid tumors and include papillary thyroid cancer (PTC), follicular thyroid cancer (FTC), and Hurthle cell thyroid cancer (HTC). Rates of lymph node metastases are different depending on histologic subtypes and <5% in FTC and between 5% and 13% in HTC. Lymph node metastasis is more frequent in PTC and while rate of clinical metastasis can be seen approximately 30% rate of routine micrometastasis can be seen up to 80%. Lymph node metastasis of DTC mostly develops first in the Level VI lymph nodes at the central compartment starting from the ipsilateral paratracheal lymph nodes and then spreading to the contralateral paratracheal lymph nodes. Spread to the Level VII is mostly after Level VI invasion. Subsequent spread is to the lateral neck compartments of Levels IV, III, IIA, and VB and sometimes to the Levels IIB and VA. Occasionally skip metastasis to the lateral neck compartments develop without spreading to the central compartments and this situation is more frequent in upper pole tumors. Although application of prophylactic central neck dissection (pCND) in DTC increases the rate of complication, due to its unclear effects on oncologic results and quality of life, the interest to the pCND is decreasing and debate on its surgical extent is increasing. pCND is not essential in DTC and characteristics of patient and tumor and experience of surgeon should be considered when deciding for pCND. Due to lower complication rate of one sided pCND compared to bilateral central neck dissection (CND), low possibility of contralateral central neck metastasis and low risk of recurrence, application of one-sided CND is logical. Although therapeutic CND (tCND) is the standart treatment when there is a clinically involved lymph node, extent of dissection is a matter of debate. A case-based decision for the extent of tCND can be made by considering patient and tumor characteristics and experience of the surgeon. Due to the higher complication risk of bilateral CND, unilateral tCND can be performed if there is no suspicious lymph node on the contralateral side and bilateral tCND can be applied when there is a suspicion for metastasis only on the contralateral side or there are features for risk of metastasis to the contralateral side. In patients with clinical central metastasis owing to intra-operative pathology results by frozen section procedure are compatible with post-operative pathology results, when there is a suspicion for contralateral metastasis, a decision for one- or two-sided dissection can be made using frozen section procedure. In DTC, it can be stated that there is a consensus in the literature about not performing prophylactic lateral neck dissection (LND), but performing therapeutic LND (tLND). In addition, there is a debate on the extent of tLND. In a meta-analysis about lateral metastasis, the rates of metastasis to the Levels IIA, IIB, III, IV, VA, and VB were 53.1%, 15.5%, 70.5%, 66.3%, 7.9%, and 21.5%, respectively. Ultrasonography (USG) is an effective procedure for detection of cervical nodal metastasis on lateral compartment. Pre-operative imaging with USG and/or combination with the fine needle aspiration biopsy (cytology/molecular test/Thyroglobulin test) can allow pre-operative detection and verification of lateral lymph node metastasis. Extent of tLND can be determined to minimize morbidity considering pre-operative USG findings, pre-operative tumor and clinical features of lateral metastasis. Especially in the presence of limited lateral metastases, limited selective LND such as Levels III, IV or Levels IIA, III, IV can be applied according to the patient. Levels IIB and VB should be added to the dissection in the presence of metastases in these regions. In cases that increase the risk of Level IIB involvement, such as presence of metastasis at Level IIA, extranodal tumor involvement, presence of multifocal tumor, and in cases that increase the risk of Level VB involvement such as macroscopic extranodal spread, and simultaneous metastases at Levels II, III, IV; Levels IIB and VB can be added to dissection material. Levels I and VA should be added to the dissection in the presence of clinically detected metastases.

Follicular and Hurthle Cell Carcinoma: Comparison of Clinicopathological Features and Clinical Outcomes

Background: Follicular thyroid carcinoma (FTC) and Hurthle cell carcinoma (HCC) are rare and aggressive thyroid cancers with limited published data comparing their outcomes or regarding their subtypes. The aim of this study was to describe clinicopathological features and compare clinical outcomes of patients with FTC and HCC based on the 2017 World Health Organization definition and extent of vascular invasion (VI). Methods: We retrospectively studied 190 patients with HCC and FTC primarily treated with surgery at Memorial Sloan Kettering Cancer Center between 1986 and 2015. Patients were classified as minimally invasive (MI), encapsulated angioinvasive with focal VI (EA-FVI), encapsulated angioinvasive with extensive VI (EA-EVI), and as widely invasive (WI). To compare clinical outcomes, patients were grouped as follows: group 1 = FTC-MI and FTC EA-FVI, group 2 = FTC EA-EVI and FTC-WI, group 3 = HCC-MI and HCC EA-FVI, group 4 = HCC EA-EVI and HCC-WI. Outcomes of interest were overall survival (OS), disease-specific survival (DSS), recurrence-free survival (RFS), locoregional recurrence-free survival (LRRFS), and distant recurrence-free survival (DRFS). Outcomes were determined using the Kaplan-Meier method and compared with log-rank test. Results: Patients with HCC (n = 111) were more likely to be older than 55 years old (59% vs. 27%, p < 0.001) with a tendency to present with more extensive VI (33% vs. 19%, p = 0.07) compared with FTC (n = 79). Comparing groups 1, 2, 3, and 4, group 4 patients were more likely to recur (DFS 98%, 93%, 98% vs. 73%, respectively, p = 0.0069). There was no statistically significant difference in OS, DSS LRRFS, or DRFS. Stratified by extent of VI (no, focal, and extensive VI), patients with extensive VI were more likely to recur (RFS 100%, 95%, 77%, p = 0.0025) and had poorer distant control (DRFS: 100%, 95%, 80%, p = 0.022), compared with patients absent or focal VI. Conclusions: Accurate assessment of the extent of VI and tumor phenotype (follicular vs. Hurthle) are essential in identifying patients at higher risk of recurrence.

Thyroid collision tumor containing oncocytic carcinoma, classical and hobnail variants of papillary carcinoma and areas of poorly differentiated carcinoma

Collision tumors are rare and may comprise components with different behavior, treatments, and prognosis. We report an unprecedented case of aggressive thyroid collision tumor containing widely invasive oncocytic carcinoma (OC), classical and hobnail (HPTC) variants of papillary carcinoma, and poorly differentiated carcinoma (PDTC). The patient underwent total thyroidectomy, radioactive iodine therapy, and within months progressed with local recurrence, and pulmonary metastases requiring neck dissection, external radiotherapy and systemic treatment with sorafenib. The rapid progression, dedifferentiated metastatic lesions, and failure to treatments resulted in the patient's death. The great variety of histological types and the evolution of this case were a challenge for the management of metastatic disease. Widely invasive OC, HPTC and PDTC are considered to have a worse prognosis. HPTC has never been reported as a component of a collision tumor. HPTC and PDTC should call attention to a possible higher-grade transformation.

Hürthle Cell Carcinoma of the Thyroid Gland: Systematic Review and Meta-analysis

INTRODUCTION

Hürthle cell carcinoma (HCC) comprises about 5% of thyroid carcinoma cases. Partly because of its rarity there is much we still need to know about HCC as compared to other histological cancer subtypes.

METHODS

We conducted a systematic literature review following PRISMA guidelines and meta-analysis, from 2000 to 2020, to investigate the main characteristics of HCC and clarify information concerning tumor behavior and treatment.

RESULTS

Our review included data from 9638 patients reported in 27 articles over the past 20 years. This tumor occurred more frequently in women (67.5%). The mean age was 57.6 years, and the mean size of the neoplasm at diagnosis was 30 mm. Extrathyroidal extension was common (24%) but lymph node metastasis was not (9%). Total thyroidectomy was the most common surgical approach, with neck dissection usually performed in cases with clinically apparent positive neck nodes. Radioiodine therapy was frequently applied (54%), although there is no consensus about its benefits. The mean 5- and 10-year overall survival was 91% and 76%, respectively.

CONCLUSION

This review serves to further elucidate the main characteristics of this malignancy. HCC of the thyroid is rare and most often presents with a relatively large nodule, whereas lymph node metastases are rare. Given the rarity of HCC, a consensus on their treatment is needed, as doubts remain concerning the role of specific tumor findings and their influence on management.

Insurance type is associated with appropriate use of surgical and adjuvant care for differentiated thyroid carcinoma

BACKGROUND

We aimed to characterize the association between differentiated thyroid cancer (DTC) patient insurance status and appropriateness of therapy (AOT) regarding extent of thyroidectomy and radioactive iodine (RAI) treatment.

METHODS

The National Cancer Database was queried for DTC patients diagnosed between 2010 and 2016. Adjusted odds ratios (AOR) for AOT, as defined by the American Thyroid Association guidelines, and hazard ratios (HR) for overall survival (OS) were calculated. A difference-in-differences (DD) analysis examined the association of Medicaid expansion with outcomes for low-income patients aged <65.

RESULTS

A total of 224,500 patients were included. Medicaid and uninsured patients were at increased risk of undergoing inappropriate therapy, including inappropriate lobectomy (Medicaid 1.36, 95% confidence interval [CI]: 1.21-1.54; uninsured 1.30, 95% CI: 1.05-1.60), and under-treatment with RAI (Medicaid 1.20, 95% CI: 1.14-1.26; uninsured 1.44, 95% CI: 1.33-1.55). Inappropriate lobectomy (HR 2.0, 95% CI: 1.7-2.3, P < .001) and under-treatment with RAI (HR 2.3, 95% CI: 2.2-2.5, P < .001) were independently associated with decreased survival, while appropriate surgical resection (HR 0.3, 95% CI: 0.3-0.3, P < .001) was associated with improved odds of survival; the model controlled for all relevant clinico-pathologic variables. No difference in AOT was observed in Medicaid expansion versus non-expansion states with respect to surgery or adjuvant RAI therapy.

CONCLUSION

Medicaid and uninsured patients are at significantly increased odds of receiving inappropriate treatment for DTC; both groups are at a survival disadvantage compared with Medicare and those privately insured.

Synchronous occurrence of Hurthle cell carcinoma with Hodgkin's lymphoma; the first reported case with literature review

Introduction

Hurthle cell carcinoma (HCC) is a rare type of thyroid cancer while Hodgkin's lymphoma (HL) is an uncommon cancer of the lymphocytes. The synchronous occurrence of HCC and HL in a single person has not been described in the literature. This report aims to present the first case of synchronous HCC and HL.

Case report

A 31-year-old male presented with a right side neck swelling for three months. Laboratory findings revealed elevated thyroglobulin (286.7 ng/ml). Ultrasound (US) examination showed several enlarged lymph nodes (<20mm) in the right side of the neck with increased vascularity. There was also a solitary solid thyroid nodule (23*20mm) in the right lobe. Fine needle aspiration cytology (FNAC) of the right lobe revealed Hurthle cell neoplasm, and right cervical lymph node was suspicious for Hodgkin's lymphoma. Right lobectomy with right lateral cervical excisional biopsy was performed. Histopathology confirmed HCC and HL.

Discussion

HCC is a differentiated cancer occurring in old age population. Multiple factors increase the risk of HCC, including the excess iodine, history of thyroid diseases, and exposure to radiation. HL is a cancer of the lymphatic system that affects young adults and older population. There is a significant association between excess body weight and cigarette smoking with the risk of HL.

Conclusion

Although extremely rare, occurrence of a few cases of other thyroid carcinomas and HL could occur. However, no relation has been described between the two cancers.

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Hurthle cell carcinoma is a rare, well-differentiated, and aggressive thyroid cancer.

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Hodgkin's lymphoma is a cancer of the lymphocytes, associated with good prognosis.

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This report presents the first case of synchronous Hurthle cell carcinoma and Hodgkin lymphoma.

Thyroid Follicular Epithelial Cell-Derived Cancer: New Approaches and Treatment Strategies

Thyroid follicular epithelial cell-derived cancer includes papillary carcinoma, follicular carcinoma, Hürthle cell carcinoma, poorly differentiated thyroid cancer, and anaplastic thyroid carcinoma. Although the incidence of thyroid cancer has increased over the past 30 years, there has not been a significant increase in patient mortality. Use of increasingly sensitive detection methods such as high-resolution imaging has enabled earlier detection and better characterization of the thyroid malignancies. In the past several years, researchers have evaluated genetic mutations promoting thyroid carcinogenesis and oncogenesis. The identification of genetic mutations is important in understanding tumor initiation and progression. Additionally, these identified mutations may also serve as potential diagnostic or prognostic indicators and therapeutic molecular targets.

Radiofrequency ablation for treatment of thyroid follicular neoplasm with low SUV in PET/CT study

OBJECTIVES

To evaluate the feasibility of radiofrequency ablation (RFA) on follicular neoplasm with low standard uptake value (SUV) in a Positron emission tomography (PET/CT) study.

METHODS

From January 2018 to July 2019, 86 consecutive patients were diagnosed with follicular neoplasm. Of the patients, 28 with PET/CT scans were enrolled in this study. All patients received ultrasound, fine/core needle aspiration, and PET/CT scan prior to treatment. In accordance with previous studies, we recommended 6 patients who had follicular neoplasm with SUVmax ≥5 undergo surgical resection due to an elevated suspicion of malignancy. For 22 patients SUVmax <5, RFA was performed using the moving shot technique. Ultrasound was performed 6 to 12 months after each procedure.

RESULTS

Statistically significant volume reductions during follow-up between values prior to RFA and 12 months post RFA were demonstrated (12.6 ± 20.9 vs. 2.4 ± 3.0 cm³, p < 0.001). Volume reduction ratios at 6-12 months (mean: 10.1 months) after RFA were 73.3% ± 17.7%. One patient presented with vocal cord palsy and recovered within 3 months after RFA. No postprocedural hypothyroidism occurred in the RFA patients.

CONCLUSIONS

By using PET/CT, we can select patients with low SUV follicular neoplasm. RFA offers a safe and feasible alternative treatment option for patients unsuitable or unwilling to undergo surgery.KEY POINTSBy using positron emission tomography-computed tomography, we can distinguish low SUV follicular neoplasm for radiofrequency ablation.For low SUV follicular neoplasm, RF ablation offers a safe and effective alternative treatment option for patients unsuitable or unwilling to undergo surgery.

Site-Specific Metastasis and Survival in Papillary Thyroid Cancer: The Importance of Brain and Multi-Organ Disease

Introduction-heterogeneity in clinical outcomes and survival was observed in patients with papillary thyroid cancer (PTC) and distant metastases. Here, we investigated the effect of distant metastases sites on survival in PTC patients. Methods-patients with a diagnosis of PTC and known metastases were identified using the Surveillance, Epidemiology, and End Results database (1975-2016). Univariate and multivariate Cox regression analyses were performed to analyze the effect of distant metastases sites on thyroid cancer-specific survival (TCSS) and overall survival (OS). Results-from 89,694 PTC patients, 1819 (2%) developed distant metastasis at the initial diagnosis, of whom 26.3% presented with the multiple-organ disease. The most common metastatic sites were lung (53.4%), followed by bone (28.1%), liver (8.3%), and brain (4.7%). In metastatic patients, thyroid cancer-specific death accounted for 73.2%. Kaplan-Meier curves showed decreased OS in patients with metastases to the brain (median OS = 5 months) and liver (median OS = 6 months) compared to lung (median OS = 10 months) and bone (median OS = 23 months). Moreover, multiple organ metastasis had a higher mortality rate (67.4%) compared to single organ metastasis (51.2%, p < 0.001). Using multivariate analysis, risk factors that significantly influence TCSS and OS were male gender (HR = 1.86, 95% CI = 1.17-2.94, p < 0.001, and HR = 1.90, 95% CI = 1.40-2.57, p = 0.009), higher tumor grade (HR = 7.31, 95% CI = 2.13-25.0, p < 0.001 and HR = 4.76, 95% CI = 3.93-5.76, p < 0.001), multiple organ involvement (HR = 6.52, 95% CI = 1.50-28.39, p = 0.026 and HR = 5.08, 95% CI = 1.21-21.30, p = 0.013), and brain metastasis (HR = 1.82, 95% CI = 1.15-2.89, p < 0.001 and HR = 4.21, 95% CI = 2.20-8.07, p = 0.010). Conclusion-the pattern of distant metastatic organ involvement was associated with variability in OS in PTC. Multi-organ metastasis and brain involvement are associated with lower survival rates in PTC. Knowledge of the patterns of distant metastasis is crucial to personalize the treatment and follow-up strategies.

Disease-free Survival of Patients with Differentiated Thyroid Cancer: A Study from a Tertiary Center in Oman

Objectives

As with global trends, the prevalence of differentiated thyroid cancer (DTC) has increased in recent years in Oman. However, to the best of our knowledge, no local studies have yet been published evaluating the prognosis of DTC cases in Oman. This study aimed to assess disease-free survival (DFS) and prognostic factors related to DTC among Omani patients attending a tertiary care center.

Methods

This retrospective, observational cohort study was conducted between January 2006 and May 2016 at the National Diabetes and Endocrine Center in Oman. Data related to DFS and prognostic factors were obtained from the electronic medical records of all ≥ 18-year-old patients diagnosed with DTC during the study period.

Results

A total of 346 DTC cases were identified. Overall, 82.7% of patients were disease-free at their last follow-up appointment. Univariate analysis indicated that various tumor characteristics including histological subtype (i.e., papillary carcinoma, Hurthle cell cancer, and minimally invasive follicular thyroid carcinoma), lymph node status, number of lymph node metastases, distant metastasis status, and TNM status (primary tumor (T), regional lymph node (N), distant metastasis (M) stage) were strong prognostic factors for DFS (p < 0.050). According to multivariate regression analysis, lymph node status, extrathyroidal extension, and angiovascular invasion were independent predictors of DFS (p < 0.050).

Conclusions

The overall prognosis of DTC among Omani patients was excellent. Treatment and follow-up strategies for patients with DTC should be tailored based on the individual’s risk factor profile.

Challenges in Cytology Specimens With Hürthle Cells

In fine-needle aspirations (FNA) of thyroid, Hürthle cells can be found in a broad spectrum of lesions, ranging from non-neoplastic conditions to aggressive malignant tumors. Recognize them morphologically, frequently represents a challenging for an adequately diagnosis and are associated with a significant interobserver variability. Although the limitations of the morphologic diagnosis still exist, the interpretation of the context where the cells appear and the recent advances in the molecular knowledge of Hürthle cells tumors are contributing for a more precise diagnosis. This review aims to describe the cytology aspects of all Hürthle cells neoplastic and non-neoplastic thyroid lesions, focusing on the differential diagnosis and reporting according to The Bethesda System for Reporting Thyroid Cytology (TBSRTC). New entities according to the latest World Health Organization (WHO) classification are included, as well as an update of the current molecular data.

Hürthle cell lesions of the thyroid: Progress made and challenges remaining

Hürthle cell-predominant thyroid fine needle aspirations (FNA) are encountered frequently in routine practice, yet they are often challenging to diagnose accurately and are associated with significant interobserver variability. This is largely due to the ubiquity of Hürthle cells in thyroid pathology, ranging from nonneoplastic conditions to aggressive malignancies. Although limitations in cytomorphologic diagnoses likely will remain for the foreseeable future, our knowledge of the molecular pathogenesis of Hürthle cell neoplasia and application of molecular testing to cytologic material have increased dramatically within the past decade. This review provides context behind the challenges in diagnosis of Hürthle cell lesions and summarizes the more recent advances in diagnostic tools.

FOLLICULAR THYROID CARCINOMA - CLINICAL AND DIAGNOSTIC FINDINGS IN A 20-YEAR FOLLOW UP STUDY

Context

Follicular thyroid carcinomas (FTC) represent 6-10 % of all thyroid carcinomas; the evolution of FTC is quite controversial, partly due to frequent changes of the histopathological definition (minimally invasive-MIFTC or widely invasive carcinoma-WIFTC) and treatment strategies adjustments.

Objective

This research aims to examine the diagnostic procedure, therapeutic attitude and survival rates of patients with FTC, over a period of 16 years in the same institution, with a follow-up of at least 4 years, by analyzing correlations between histology subtype, treatments and the rate of recurrent disease.

Subjects and methods

We have studied 5891 patients with thyroid carcinomas who have undergone surgical or oncological treatment within the institution, between 1^st January 2000 - 31^st December 2015; among them we found 133 patients (2.25%) with "pure" follicular thyroid carcinoma: 114 (86%) women and 19 (14%) men, with a female-male ratio of 6:1. The age of the patients ranged from 10 to 76 years, with an average of 47.8 years. Statistical analysis was done comparing differences among groups of MIFTC and WIFTC.

Results

There was an unexpected high percentage of WIFTC and also an increased number of biochemically persistent and/or recurrent disease in patients with MIFTC. A stronger correlation was observed with the tumour dimensions, rather than with the histopathological subtype.

Conclusions

This research observed that overall survival was associated with tumour size rather than histopathological subtype and there is an important need to perform further studies to assess the effectiveness of treatment strategies.

Challenges in the Correct Assessment of a Case of Aggressive Thyroid Carcinoma with Synchronous Breast Cancer: A Case Report and Review of the Literature of Essential Role of Radiopharmaceuticals

Thyroid carcinoma represents a complex pathology that can still be considered a medical challenge, despite having a better prognosis and life expectancy than most other neoplasms; also the scenario of multiple malignancies involving thyroid cancer is nowadays a common reality.

MATERIALS AND METHODS

We reviewed the literature regarding the aggressive presentation of synchronous thyroid and breast cancer. In the current paper, we report the case of a 59 years-old woman, diagnosed with invasive ductal breast carcinoma and papillary thyroid carcinoma, presenting a natural history of both aggressive synchronous tumors. At the moment of hospitalization, the diagnosis was breast carcinoma with multiple secondary lesions, suggestive of lung and bone metastases, and nodular goiter.

RESULTS

Searching the literature in PUBMED with the terms "thyroid carcinoma and synchronous breast carcinoma, we found 86 studies; introducing the term "aggressive," the result included 4 studies, among which, none showed to be relevant to the terms aggressive and synchronous. A similar search was done in SCOPUS finding 92 documents and after introducing the term aggressive, the number of papers was 8, none including the literature on synchronous aggressive metastatic thyroid and breast carcinoma. A majority of imaging diagnostic tools were used in this particular medical case in order to ensure the best potential outcome. The final diagnosis was papillary thyroid carcinoma with lung and unusual multiple bone metastases and synchronous invasive ductal breast carcinoma with subcutaneous metastases.

CONCLUSION

The case illustrates the challenges in the correct assessment of oncologic patients, despite the advances in medical imaging and technologies and underlines the essential role of nuclear medicine procedures in the diagnostic and therapy protocols.

Hurthle cell carcinoma in childhood: A retrospective analysis of five cases and review of pediatric literature

BACKGROUND

the available studies on Hurthle cell carcinoma (HCC) in pediatric age are scarce and based on isolated case reports. Aims of the present study were to review the available pediatric literature on HCC (2000-2019), to describe the cohort of children with this cancer histotype, and to estimate its relative prevalence in pediatric age.

PROCEDURE

We retrospectively reconstructed an HCC course in five patients < 19 years who were identified in our departments during the period 2000-2019, and we reviewed the available pediatric studies on this differentiated thyroid cancer (DTC) variant.

RESULTS

HCC occurred with a relative prevalence of 5.8% at a median chronological age of 12.5 years. None of HCC patients exhibited, at diagnosis, thyroid dysfunction, extensive lateral neck disease, or distant metastases, and all showed a persistent remission over time. Three patients showed, at diagnosis, antecedents of other diseases (Hashimoto's thyroiditis, neurofibromatosis type 1, and osteosarcoma).

CONCLUSIONS

(1) In childhood, the relative prevalence of HCC among different thyroid cancer histotypes is 5.8%, that is close to the one previously reported both in the general population and in other less numerous children's cohorts; (2) HCC may develop even early, at the age of 7; (3) in childhood, HCC does not seem to have a more aggressive behavior when compared with other DTC histotypes; (4) antecedents of other diseases are not infrequent in the history of children with HCC.

METASTATIC HÜRTHLE CELL CARCINOMA PRESENTING WITH LOW FREE THYROXINE, SEVERE HYPERCALCEMIA AND SPURIOUS GROWTH HORMONE PRODUCTION

Objective

Hürthle cell tumors constitute about 5% of thyroid neoplasms. They have malignant potential, behaving very aggressively compared to other differentiated thyroid cancers. The objective of this case report is to describe a case of a Hürthle cell carcinoma with a single large metastasis in the liver presenting almost 17 years after hemithyroidectomy. We highlight the difficulties in making a histologic diagnosis and the unpredictable nature of this cancer.

Methods

The patient history and biochemistry were detailed. Thyroid function tests analyzed on multiple platforms (single-photon emission computed tomography, dynamic magnetic resonance imaging, technetium-99m bone scan, and radioactive iodine) were used to aid biochemical and radiologic diagnosis.

Results

The patient's thyroid function test showed persistently low free thyroxine concentrations with normal thyroid stimulating hormone and free triiodothyronine, suggesting rapid deiodination in the context of a large liver lesion. Radiologic and morphologic appearances of the liver lesion led to an initial misdiagnosis of primary hepato-cellular carcinoma, revised to metastatic Hürthle cell carcinoma after positive immunochemistry. Nonparathyroid hormone-related intractable hypercalcemia of malignancy with an unusual pattern of elevated 1,25-dihydroxyvitamin D and raised fibroblast growth factor 23 concentrations culminated in his demise.

Conclusions

In Hürthle cell carcinomas treated with partial thyroidectomy, subsequent abnormal thyroid functions tests may herald a more sinister underlying diagnosis. The management of Hürthle cell carcinoma relies heavily on the initial histology results. Histologic diagnosis should be sought earlier in abnormal and suspicious distant masses. Malignant hypercalcemia poses a great challenge in delayed presentations and can prove resistant to conventional treatments.

Clinicopathological features and outcomes after radioactive iodine treatment of oncocytic well-differentiated thyroid carcinomas

OBJECTIVE

The aim of this study was to compare the clinicopathological features of Hürthle cell carcinomas (HCC) and oncocytic papillary thyroid carcinomas (OPTC) and to evaluate their response to radioactive iodine (RAI) treatment.

METHODS

We retrospectively reviewed the charts of patients with histopathologically verified OPTC (group 1) and HCC (group 2), during a 17-year period. All patients underwent total thyroidectomy and received RAI adjuvant therapy. Clinicopathological characteristics of the two groups were compared. Response to initial therapy was assessed 6 to 24 months after RAI ablation according to the American Thyroid Association dynamic risk reclassification. Clinical outcomes were evaluated.

RESULTS

A total of 28 patients (8 OPTC and 20 HCC) were included. There was no significant difference in clinicopathological features including sex, age, tumour size and vascular invasion. Distant metastases were absent in both groups. OPTC, however, presented more features of local invasion (50% vs. 10%, P = 0.03), extrathyroidal extension (25% vs. 0%, P = 0.07) and lymph node involvement (37.5% vs. 0%, P = 0.01). Median cumulative RAI activity administered to both groups was 200 mCi (range: 100-300 mCi). Response to RAI therapy was excellent in all HCC and 87.5% of OPTC (P = 0.28). One patient with OPTC (12.5%) presented an indeterminate response. Clinical outcomes were favourable after a median follow-up of 87.5 and 49 months, respectively.

CONCLUSION

Although OPTC presented more locoregional invasion, clinicopathological characteristics of OPTC and HCC were comparable. Both OPTC and HCC were iodine responsive. We suggest that adjuvant RAI therapy after total thyroidectomy is beneficial for OPTC and HCC and may improve disease-free survival.

Multi-omics Signatures and Translational Potential to Improve Thyroid Cancer Patient Outcome

Recent advances in high-throughput molecular and multi-omics technologies have improved our understanding of the molecular changes associated with thyroid cancer initiation and progression. The translation into clinical use based on molecular profiling of thyroid tumors has allowed a significant improvement in patient risk stratification and in the identification of targeted therapies, and thereby better personalized disease management and outcome. This review compiles the following: (1) the major molecular alterations of the genome, epigenome, transcriptome, proteome, and metabolome found in all subtypes of thyroid cancer, thus demonstrating the complexity of these tumors and (2) the great translational potential of multi-omics studies to improve patient outcome.

Concurrence of Papillary Thyroid Carcinoma and Hürthle Cell Carcinoma in an Iranian Woman with Hashimoto's Thyroiditis

The most usual form of the endocrine carcinoma is thyroid cancer (TC). In addition to papillary thyroid carcinoma (PTC), recent studies revealed incidence of RET/PTC rearrangement in other tumors, like Hürthle cell carcinoma (HCC) and even in non-carcinomatous disorders like Hashimoto's thyroiditis. Here, we present a case with concurrence of papillary thyroid carcinoma and Hürthle cell carcinoma.

A 60-year-old woman referred to our hospital with a mass in her neck. Physical examinations revealed painful swelling in the thyroid. Ultrasonographic examination showed two hypoechoic nodules in the right lobe. Hürthle cell variant papillary carcinoma was suggested in the cytology report of the fine needle aspiration. Permanent histopathological diagnosis was co-existence of papillary thyroid carcinoma and Hürthle cell carcinoma. The patient was asymptomatic in 14 months follow up.

Concurrence of papillary carcinoma and Hürthle cell carcinoma is a rare form of thyroid malignancies, with doubtful cytogenetic findings and biological behaviors. The results showed that it is necessary for the surgeons and pathologists to be aware of lesions for the optimal diagnostic and therapeutic interventions. Also, it is vital to follow up patients with the Hashimot’s thyroiditis who have multiple nodules to detect occult thyroid cancers and decide for better therapeutic programs.

Indeterminate thyroid nodules (TIR3A/TIR3B) according to the new Italian reporting system for thyroid cytology: A cytomorphological study

OBJECTIVE

The Italian reporting system for thyroid cytology classifies indeterminate lesions as TIR3A (low risk) or TIR3B (high risk) and is meant to provide practical guidance rather than a detailed consideration of morphological features. We aimed to assess which cytological features have the most diagnostic value and whether they are effective in classifying nodules as either TIR3A or TIR3B and in predicting histological outcomes.

METHODS

Thyroid fine-needle aspirates from 111 indeterminate nodules were reviewed blinded to clinical information, TIR3A/TIR3B classification, and histology in order to assess which cytological features (pooled into artefacts, smear background, architectural and nuclear atypia, and oncocytes) differentiate TIR3A from TIR3B, and benign from malignant histological outcomes.

RESULTS

Of the cytological features examined, those specific for TIR3B included high cellularity, nuclear atypia, oncocyte predominance and transgressing vessels. Features specific for TIR3A included artefacts, low cellularity and oncocyte sparseness. Other features, such as microfollicules/trabeculae, were non-specific. Due to the different distributions of these features, three TIR3B subgroups were identifiable: follicular lesions with oncocytic changes, pure follicular lesions, and follicular lesions with nuclear atypia, whereas no subgroups were identifiable in TIR3A. Nuclear atypia was a significant indicator of malignancy, whereas oncocyte predominance was not a reliable predictor of malignancy. High cellularity and microfollicules/trabeculae were not indicative of any histological outcome.

CONCLUSIONS

The majority of the assessed features were good predictors of histological outcomes. The TIR3A category included undefined nodules due to the absence of characterising features, whereas the TIR3B category included nodules with a greater number of distinguishing features.

LATERAL NECK DISSECTION FOR AGGRESSIVE VARIANTS OF WELL-DIFFERENTIATED THYROID CANCER

Objective: Well-differentiated thyroid cancer (WDTC) is characterized by favorable disease course and excellent survival. However, some histologic subtypes, known as aggressive histologic variants (AHVs), present a more aggressive behavior than conventional WDTC. The aim of this study was to evaluate the pattern of nodal involvement and factors influencing prognosis in N1b patients with AHVs. Methods: A multicentric retrospective analysis of patients who underwent therapeutic lateral neck dissection (ND) for WDTC between 1994 and 2015 was accomplished. AHVs included the following subtypes: tall cell, Hürtle cell, diffuse sclerosing, and poorly differentiated papillary thyroid cancer. Results: The study included a total of 352 N1b patients, 40 (11.4%) of whom had AHVs. AHVs present a similar distribution of positive nodes if compared with conventional WDTC. In AHV patients, 5-year overall survival (OS), disease-specific survival (DSS), locoregional control, and metastasis-free survival were 82.2%, 93.6%, 80.3%, and 87.3%, respectively. Advanced age (>55 years) was the only significant factor affecting survival (OS, P<.001; DSS, P = .011) in this group. In the AHV group, there were 9 (22.5%) recurrences; patients with regional recurrence and without distant metastases were effectively treated by surgery. Conclusion: The distribution of positive lymph nodes in case of AHVs is similar to that of conventional WDTC, with only level V at a relatively greater risk of harboring metastases in the former group. Survival outcomes in N1b patients with AHVs remain optimal. Total thyroidectomy, ND, and adjuvant radioiodine administration have been demonstrated to be effective treatments in the setting of AHVs. Abbreviations: AHV = aggressive histologic variant; DOD = died of disease; DSS = disease-specific survival; DSV = diffuse sclerosing variant; ETE = extrathyroidal extension; HCC = Hürthle cell carcinoma; LRC = locoregional control; LVI = lymphovascular invasion; MFS = metastasis-free survival; ND = neck dissection; NED = no evidence of disease; OS = overall survival; PDA = poorly differentiated areas; PTC = papillary thyroid carcinoma; RAI = radioiodine therapy; TCV = tall cell variant; WDTC = well-differentiated thyroid cancer.

Approach the Invasive Potential with Hurthle Cell Tumors of Thyroid

To observe the expression of P53, CyclinD1, Ki-67, Galectin-3, COX-2, Bcl-2 and approach their contribution on assessing the invasive potential for Hurthle cell tumors. Seventy-three cases of Hurthle cell tumor were collected for immunohistochemistry staining. The patients were followed up with 8 months to 5 years. Tumors were divided into four grades according to invasion and diameter:(1) extremely low risk (27 cases that less than 2 cm and without invasion), (2) low risk (18 cases that within 2-3.9 cm and without invasion), (3) moderate risk (21 cases that achieve 4 cm and without invasion), (4) high risk (7 cases that with invasion of capsule/vessel in spite of the diameter). Immunostaining presented that all 73 cases were positive with Galectin-3, COX-2 and Bcl-2. For each group, P53 positive were 29.6%, 55.6%, 90.5%, 100.0%; CyclinD1 stained with 7.4%,22.2%,52.4%,100.0% and Ki-67 were 0.0%,5.6%,9.5%,28.6%, respectively. The higher risk of tumor, the more cases that positive expressed P53 and CyclinD1. After following up within 49 patients, two of the recurring cases were positive with P53 and CyclinD1 and one of which was also highly expressed Ki-67. Detecting P53, CyclinD1 and Ki-67 might provide reference for invasive potential assessment with Hurthle cell tumors but not Galectin-3, COX-2 and Bcl-2.

Thyroseq V3 Molecular Profiling for Tailoring the Surgical Management of Hürthle Cell Neoplasms

Hürthle cell predominant thyroid nodules often confound the diagnostic utility of fine needle aspiration biopsy (FNAB) with cytology often interpreted as a Hürthle cell lesion with an indeterminate risk of malignancy, Bethesda category (BC) III or IV. Molecular diagnostics for Hürthle cell predominant nodules has also been disappointing in further defining the risk of malignancy. We present a case of a slowly enlarging nodule within a goiter initially reported as benign on FNAB, BC II but on subsequent FNAB suspicious for a Hürthle cell neoplasm, BC IV. The patient had initially requested a diagnostic lobectomy for a definitive diagnosis despite a higher risk of malignancy based on the size of the nodule > 4 cm alone. To better tailor this patient's treatment plan, a newer expanded gene mutation panel, ThyroSeq® v3 that includes copy number alterations (CNAs) and was recently found to have greater positive predictive value (PPV) for identifying Hürthle cell carcinoma (HCC), was performed on the FNAB material. Molecular profiling with ThyroSeq® v3 was able to predict a greater risk of carcinoma, making a more convincing argument in favor of total thyroidectomy. Surgical pathology confirmed a Hürthle cell carcinoma with 5 foci of angioinvasion and foci of capsular invasion.

Differential Expression of Glycolysis-Related Proteins in Follicular Neoplasms versus Hürthle Cell Neoplasms: A Retrospective Analysis

Purpose

Although currently classified as variants of follicular neoplasms (FNs), Hürthle cell neoplasms (HCNs) exhibit distinct biological characteristics. Hence, the metabolism of both neoplasms may also be different. The aims of this study were to investigate and compare the expression of glycolysis-related proteins in HCNs and FNs and to determine the clinical implications of such expression.

Methods

Tissue microarrays were constructed with 265 samples of FNs (112 follicular carcinomas (FCs) and 153 follicular adenomas (FAs)) as well as 108 samples of HCNs (27 Hürthle cell carcinomas (HCCs) and 81 Hürthle cell adenomas (HCAs)). Immunohistochemical staining for the glycolysis-related molecules Glut-1, hexokinase II, CAIX, and MCT4 was performed.

Results

The expression levels of Glut-1, hexokinase II, CAIX, and MCT4 were significantly higher in HCNs than in FNs (p < 0.001). Glut-1, hexokinase II, CAIX, and MCT4 expression levels were highest in HCC, followed by HCA, FC, and FA (all p < 0.001). In HCC, hexokinase II positivity was associated with large tumor size (>4 cm) (p = 0.046), CAIX positivity with vascular invasion (p = 0.005), and MCT4 positivity with extrathyroidal extension (p = 0.030).

Conclusion

The expression levels of the glycolysis-related proteins Glut-1, hexokinase II, CAIX, and MCT4 were higher in HCNs than in FNs and in HCCs than in HCAs.

Etiopathogenesis of oncocytomas

Oncocytomas are distinct tumors characterized by an abnormal accumulation of defective and (most probably) dysfunctional mitochondria in cell cytoplasm of such tumors. This particular phenotype has been studied for the last decades and the clarification of the etiopathogenic causes are still needed. Several mechanisms involved in the formation and maintenance of oncocytomas are accepted as reasonable causes, but the relevance and contribution of each one for oncocytic transformation may depend on different cancer etiopathogenic contexts. In this review, we describe the current knowledge of the etiopathogenic events that may lead to oncocytic transformation and discuss their contribution for tumor progression and mitochondrial accumulation.