Update on anaplastic thyroid carcinoma: morphological, molecular, and genetic features of the most aggressive thyroid cancer

Cytological Features and Mimickers of Thyroid Gland Sarcomas: A Case-Based Study

Sarcomas of thyroid glands represent a distinctive subset of rare and perplexing anomaly that present a challenges in the field of thyroid pathology. Thyroid sarcomas, primary or secondary, are exceptionally rare with only a handful of case reports documented so far. The challenges lie in the fact that certain primary thyroid malignancies of epithelial origin may exhibit spindle cell morphology, making them difficult to differentiate from thyroid sarcomas. Despite the morphological similarities, discerning between these entities is crucial due to their distinct treatment and management implications. This report documents a series of unusual types of sarcoma in the thyroid gland. The aim is to explore the peculiarities of these lesions, the diagnostic challenges faced as well to study the potential implications for both clinicians and patients.

MRI features of histological subtypes of thyroid cancer in comparison with CT findings: differentiation between anaplastic, poorly differentiated, and papillary thyroid carcinoma

PURPOSE

This study aimed to evaluate the MRI features of the main histological subtypes of thyroid cancer and enable differentiation between anaplastic thyroid carcinoma (ATC), poorly differentiated thyroid carcinoma (PDTC), and papillary thyroid carcinoma (PTC).

MATERIALS AND METHODS

This study included 79 patients with histopathologically proven thyroid cancer (14 ATCs, 8 PDTCs, and 57 PTCs) who underwent neck MRI. MRI images were retrospectively reviewed and compared between the three pathologies.

RESULTS

The maximum diameter was larger in ATCs and PDTCs than in PTCs (65.2 mm and 38.4 mm vs. 26.0 mm, p < 0.01). The signal intensity ratio of the solid components on T2-weighted images (T2WIs) was higher in ATCs than in PTCs (1.13 vs. 0.89, p < 0.05). The predominant signal intensity of the solid components on T2WI exhibited hyperintensity relative to the spinal cord in ATCs more frequently than in PTCs (71% vs. 30%, p < 0.01), whereas hypointensity was more frequent in PTCs than in ATCs and PDTCs (60% vs. 0% and 13%, p < 0.01). Intratumoral ring-shaped hypointensity on T2WI was more frequent in ATCs than in PDTCs and PTCs (64% vs. 13% and 18%, p < 0.01). An ill-defined margin was more frequent in ATCs and PDTCs than in PTCs (93% and 63% vs. 25%, p < 0.01). Extrathyroidal extension, tracheal invasion, esophageal invasion, vascular invasion, and venous thrombosis were more frequently observed in ATCs than in PTCs (p < 0.05).

CONCLUSIONS

MRI could characterize the differences between ATCs, PDTCs, and PTCs.

SATB2 is an Emergent Biomarker of Anaplastic Thyroid Carcinoma: A Series with Comprehensive Biomarker and Molecular Studies

Anaplastic thyroid carcinoma (ATC) is a rare and aggressive thyroid malignancy typically comprised of undifferentiated tumor cells with various histologic morphologies, which makes the diagnosis challenging. These tumors commonly show loss of thyroglobulin and TTF1 with preservation of cytokeratin (67%) and Paired Box Gene 8 (PAX8) (55%) expression. Identification of a sensitive immunohistochemical stain to aid in the diagnosis of ATC would be beneficial. Immunohistochemistry (IHC) against special AT-rich sequence-binding protein 2 (SATB2) protein is a sensitive and specific marker expressed in colorectal adenocarcinoma and bone or soft tissue tumors with osteoblastic differentiation. However, SATB2 is also expressed in other sarcomatous/undifferentiated neoplasms lacking osteoblastic differentiation. Using quantitative reverse transcription PCR (RT-qPCR) we showed that there is variable expression of SATB2 mRNA expression in ATCs. To evaluate the role of SATB2 protein expression in ATC, we performed PAX8, SATB2, pancytokeratin (AE1/AE3 & CAM5.2), claudin-4 and TTF1 immunostaining on 23 cases. ATCs showed retained expression of PAX8 in 65% (15/23); SATB2 was detected in 74% (17/23); pancytokeratin was expressed in 65% (15/23); claudin-4 was expressed in 35% (8/23) and TTF1 showed expression in 13% (3/23) of cases. Furthermore, 83% (5/6) of ATCs which lacked SATB2 expression, retained PAX8 expression, while 88% (7/8) of the tumors without PAX8 expression were positive for SATB2. Differentiated follicular cell-derived thyroid cancers (n = 30), differentiated high grade thyroid carcinoma (n = 3), and poorly differentiated thyroid carcinoma (n = 8) were negative for SATB2 immunoreactivity. Next-generation selected cases detected the commonly identified oncogenic variants including those in BRAF, RAS, TP53, and TERT promoter. Overall, we hereby demonstrate that SATB2 IHC may be used to support the diagnosis of ATC.

Anaplastic Thyroid Carcinoma: The Great Masquerader

Anaplastic thyroid carcinoma (ATC) has been regarded as the rarest form of thyroid malignancy, which entails around 2% of thyroid malignancies. It traditionally presents with rapidly enlarging anterior neck swelling with obstructive symptoms. Due to its rich blood supply and lymphatic drainage, the thyroid gland is resistant to infection. Parallel to that, the presentation of thyroid abscess frequently points towards an underlying upper respiratory tract infection. We present a case involving an elderly female presenting with a thyroid abscess, which later turned out to be ATC following a histopathological diagnosis of the thyroid gland. The initial cytology workout was negative for malignancy. We highlight the relatively uncommon presentation along with its management.

RON receptor tyrosine kinase regulates glycolysis through MAPK/CREB signaling to affect ferroptosis and chemotherapy sensitivity of thyroid cancer cells

Anaplastic thyroid cancer (ATC) is one of the deadliest and most aggressive human malignancies for which there is currently no effective treatment. Tyrosine kinase receptor RON is highly expressed in various cancer types, including colon, pancreatic and thyroid cancer. However, its underlying role in ATC is not fully understood. The present study investigated the therapeutic potential and molecular mechanism of RON in ATC. RON expression in thyroid cancer cells was detected by western blotting. Glycolysis was assessed by measuring the extracellular acidification rate, glucose uptake, lactate concentration, and expression levels of glucose transporter 1, hexokinase 2 and pyruvate kinase M1/2. In addition, ferroptosis was assessed by detecting the levels of total iron, lipid peroxide and reactive oxygen species, and the expression levels of ferroptosis‑related proteins. Furthermore, mitochondrial function were assessed by JC‑1 staining and detection kits, respectively. The results demonstrated that RON was highly expressed in thyroid cancer cell lines. Furthermore, RON interference inhibited glycolysis, promoted ferroptosis, elevated cell sensitivity to chemotherapy and affected mitochondrial function in thyroid cancer cells. Further experiments demonstrated that RON interference affected the ferroptosis levels in thyroid cancer cells by inhibiting the glycolysis process. Mechanistically, the present results indicated that RON may affect ferroptosis, glycolysis and chemotherapy sensitivity by regulating MAPK/cAMP‑response element binding protein (CREB) signaling in thyroid cancer cells. In conclusion, the present study demonstrated that RON affected ferroptosis, glycolysis and chemotherapy sensitivity in thyroid cancer cells by regulating MAPK/CREB signaling, demonstrating its potential as a therapeutic target in thyroid cancer cells.

Combination of Dabrafenib and Trametinib in Patients with Metastatic BRAFV600E-Mutated Thyroid Cancer

PURPOSE

BRAF mutations are detected in 30%-80% of papillary thyroid cancer (PTC) cases. DaBRAFenib and trametinib showed promising antitumor activity in patients with BRAFV600E-mutated metastatic melanoma and non-small cell lung cancer. This study aimed to evaluate the efficacy and safety of daBRAFenib and trametinib in patients with metastatic BRAFV600E-mutated thyroid cancer.

MATERIALS AND METHODS

This was a retrospective study to evaluate the efficacy of daBRAFenib and trametinib in patients with metastatic BRAFV600E-mutated PTC. The patients received daBRAFenib 150 mg twice daily and trametinib 2 mg once daily at the Samsung Medical Center. This study evaluated the progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR) overall survival (OS), and safety of daBRAFenib and trametinib.

RESULTS

Between December 2019 and January 2022, 27 PTC patients including eight patients with poorly differentiated or anaplastic transformation, received daBRAFenib and trametinib. The median age was 73.0 years, and the median follow-up period was 19.8 months. The majority (81.5%) had undergone thyroidectomy, while 8 patients had received prior systemic treatments. ORR was 73.1%, with 19 partial responses, and DCR was 92.3%. Median PFS was 21.7 months, and median OS was 21.7 months. Treatment-related adverse events included generalized weakness (29.6%), fever (25.9%), and gastrointestinal problems (22.2%). Dose reduction due to adverse events was required in 81.5% of the patients.

CONCLUSION

DaBRAFenib and trametinib demonstrated a high ORR with promising PFS; however, most patients with BRAFV600E-mutated metastatic PTC required a dose reduction.

Predictors of thyroid cancer survival in Saudi Arabia: A retrospective 10-year analysis

Background

Thyroid cancer (TC) is becoming more prevalent in Saudi Arabia, currently ranking among the top three cancers affecting women. Despite its rising prevalence, there has been limited assessment of the factors influencing the survival rate (SR) among the Saudi population over an extended period. Therefore, this study aims to address this critical gap in knowledge by identifying the factors affecting the SR of TC, comparing the SR with previous studies, and exploring potential areas for improving the SR of patients.

Methods

A retrospective study analyzed secondary data from patients diagnosed with TC, as recorded in the King Abdulaziz Medical City Cancer Registry in Riyadh, Saudi Arabia, over 10 years from 2009 to 2018.

Results

Of the total 665 TC cases, the mean age at diagnosis was 46.2 years (±SD 16), and most patients were women (78.5%), with the majority being under 50 years old. The most common type of cancer was papillary thyroid carcinoma, comprising 88.6% of all TCs. Over half of the cases were localized to one of the lobes of the thyroid gland, with almost equal frequency between the two lobes. The 5-year SR of localized papillary thyroid carcinoma reached 96.5%, in contrast to the extremely low SR of anaplastic thyroid carcinoma, where most patients died within a few months of the diagnosis. Factors such as morphology, tumor extension, male gender, and age at diagnosis significantly impacted patient survival, as analyzed by the Kaplan-Meier test (p < 0.001). Compared to other types of cancer, those with anaplastic thyroid carcinoma had a lower SR.

Conclusion

The SR of TC patients is predicted by factors such as their age, morphological type, and the presence of distant metastasis.

Targeting PEAK1 sensitizes anaplastic thyroid carcinoma cells harboring BRAFV600E to Vemurafenib by Bim upregulation

Pseudopodium-enriched atypical kinase 1 (PEAK1) has been demonstrated to be upregulated in human malignancies and cells. Enhanced PEAK1 expression facilitates tumor cell survival and chemoresistance. However, the role of PEAK1 inhibition to anaplastic thyroid carcinoma cell (ATC) and vemurafenib resistance is still unknown. Here, we observed that targeting PEAK1 inhibited cell viability and colony formation, but not cell apoptosis in both of the 8505C and Hth74 cells in vitro. Targeting PEAK1 sensitized 8505C and Hth74 cells to vemurafenib by inducing cell apoptosis, and thereby decreasing cell viability. Mechanistically, vemurafenib treatment upregulated PEAK1 expression. Combined PEAK1 depletion and Vemurafenib treatment upregulated Bim expression. Targeting PEAK1 sensitized vemurafenib-induced apoptosis by upregulating Bim. In conclusion, vemurafenib resistance in ATC cells harboring BRAFV600E is associated with PEAK1 activation, resulting in the inhibition of pro-apoptotic Bim protein. Therefore, targeting PEAK1 may be an effective strategy to sensitize ATC harboring BRAFV600E to vemurafenib.

The Role of Lipid Metabolism Disorders in the Development of Thyroid Cancer

Thyroid cancer (TC) is a neoplasm with an increasing incidence worldwide. Its etiology is complex and based on a multi-layered interplay of factors. Among these, disorders of lipid metabolism have emerged as an important area of investigation. Cancer cells are metabolically reprogrammed to promote their rapid growth, proliferation, and survival. This reprogramming is associated with significant changes at the level of lipids, mainly fatty acids (FA), as they play a critical role in maintaining cell structure, facilitating signaling pathways, and providing energy. These lipid-related changes help cancer cells meet the increased demands of continued growth and division while adapting to the tumor microenvironment. In this review, we examine lipid metabolism at different stages, including synthesis, transport, and oxidation, in the context of TC and the effects of obesity and hormones on TC development. Recent scientific efforts have revealed disturbances in lipid homeostasis that are specific to thyroid cancer, opening up potential avenues for early detection and targeted therapeutic interventions. Understanding the intricate metabolic pathways involved in FA metabolism may provide insights into potential interventions to prevent cancer progression and mitigate its effects on surrounding tissues.

Comparative study between poorly differentiated thyroid cancer and anaplastic thyroid cancer: real-world pathological distribution, death attribution, and prognostic factor estimation

Background

The clinic-pathological boundary between poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) is unclear due to a wide spectrum of histopathological features and the rarity of the disease. In addition to that, with the highest mortality rate and non-standard treatment modality, the PDTC/ATC population has not been subjected to comprehensive description and comparison with the extent of histological characteristics, therapeutic response, prognostic factors, and death attribution analysis.

Method

A total of 4,947 PDTC/ATC patients from 2000 to 2018 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier survival curve estimation and Cox proportional hazard regression were applied.

Results

Overall, the 5- and 10-year DSS for PDTC were 71.9% and 68.0%, respectively, whereas the 5- and 10-year OS are 59.3% and 51.2%, respectively. The median survival time for ATC patients was 3 months with 1-year OS being 26.9% and 1-year DSS being 31.2%. During the follow-up period, 68.1% of the PDTC/ATC cohort were dead, 51.6% of which were attributed to thyroid malignancies and 16.5% to non-thyroid causes. The top three common non-thyroid causes of death were miscellaneous cancers, lower respiratory system disease, and heart disease. The histological feature of papillary thyroid cancer (PTC) was the leading pathological category for PDTC patients (51.7%), whereas 76.7% of ATC patients' pathological feature was characterized as unidentifiable. Sarcoma histological characteristics found in ATC cases suffer the highest overall mortality (vs. PTC, HR = 2.61, 95% CI 1.68-4.06, P < 0.001). Older age unidentifiable histology feature, more advanced AJCC N1b, AJCC M1, and SEER stage, tumor size larger than 5 cm, and more invasive tumor extension were independent bad outcome predictors.

Conclusion

The populational analysis of the PDTC/ATC cohort has provided reliable support for better understanding of the difference between PDTC and ATC cases and the guidance of clinical practice and further studies.

When to settle for SETTLE! A lesson learned from our cases

Spindle epithelial tumor with thymic like elements (SETTLE) is a biphasic tumor composed of epithelial and spindle cell components. It is an uncommon indolent tumor arising in the thyroid gland and most commonly affects the children and young adults. This entity is mostly overlooked because of its rarity and diagnostic difficulty on morphology. We discuss two cases of SETTLE with varied presentation, diagnostic challenges and lessons learnt from them.SETTLE should be considered as a differential especially when dealing with a thyroid lesion in young and adolescent. The article discusses the histologic details and common mimickers to be borne in mind aiding in arrival at the final diagnosis on biopsy specimens.

Evaluation of the Therapeutic Effects of Harmine on Anaplastic Thyroid Cancer Cells

Anaplastic thyroid carcinoma (ATC) is an extremely difficult disease to tackle, with an overall patient survival of only a few months. The currently used therapeutic drugs, such as kinase inhibitors or immune checkpoint inhibitors, can prolong patient survival but fail to eradicate the tumor. In addition, the onset of drug resistance and adverse side-effects over time drastically reduce the chances of treatment. We recently showed that Twist1, a transcription factor involved in the epithelial mesenchymal transition (EMT), was strongly upregulated in ATC, and we wondered whether it might represent a therapeutic target in ATC patients. To investigate this hypothesis, the effects of harmine, a β-carboline alkaloid shown to induce degradation of the Twist1 protein and to possess antitumoral activity in different cancer types, were evaluated on two ATC-derived cell lines, BHT-101 and CAL-62. The results obtained demonstrated that, in both cell lines, harmine reduced the level of Twist1 protein and reverted the EMT, as suggested by the augmentation of E-cadherin and decrease in fibronectin expression. The drug also inhibited cell proliferation and migration in a dose-dependent manner and significantly reduced the anchorage-independent growth of both ATC cell lines. Harmine was also capable of inducing apoptosis in BHT-101 cells, but not in CAL-62 ones. Finally, the activation of PI3K/Akt signaling, but not that of the MAPK, was drastically reduced in treated cells. Overall, these in vitro data suggest that harmine could represent a new therapeutic option for ATC treatment.

Glomangiosarcoma-like Anaplastic Transformation in Papillary Thyroid Carcinoma: A Novel Form of Heterologous Differentiation and a Systematic Review of Heterologous Element Prevalence

Anaplastic thyroid carcinoma (ATC) demonstrates a wide variety of morphologies and is characteristically associated with a differentiated thyroid carcinoma component. Heterologous differentiation is a rare, potentially challenging phenomenon in ATC, mostly observed as osteosarcomatous or chondrosarcomatous differentiation. We now describe a novel 'glomangiosarcoma-like' differentiation, review our archival experience from two institutions (UPMC, CC), and perform a systematic review for the prevalence of heterologous elements in ATC. The patient is a 57-year-old female who presented with 4.5 cm left thyroid, and 3.4 cm neck masses. Histologically, the thyroid demonstrated a differentiated high grade papillary thyroid carcinoma, tall cell and hobnail/micropapillary subtypes transitioning into an anaplastic component with spindled to ovoid cells with hemangiopericytoma-like vasculature showing CD34 positivity, variable muscle marker expression and pericellular lace-like type IV collagen deposition. The neck mass consisted solely of the latter morphology. Targeted next-generation sequencing was performed on high grade DTC and adjacent ATC from the thyroid as well as ATC from the neck metastasis. All three components shared BRAFV600E, TERT promoter, and PIK3CA mutations confirming a clonal origin. Archival (UPMC: n = 150, CC: n = 74) and literature review showed no prior examples. Systematic review and meta-analysis of prevalence showed a baseline pooled prevalence (generalized linear mixed model) of heterologous elements of any type to be 1.6% (95% confidence interval: 1.0-2.6%) for studies where this was specifically addressed. ATC with glomangiosarcoma-like heterologous differentiation is a rarity among an already rare morphologic category with unique diagnostic pitfalls.

Anaplastic thyroid cancer: Pathogenesis, prognostic factors and genetic landscape (Review)

Anaplastic thyroid cancer (ATC) is a rare and aggressive form of thyroid malignancy, presenting significant challenges in diagnosis and treatment. The rarity of this cancer and its aggressive nature make an accurate diagnosis difficult, requiring a multidisciplinary approach and various imaging techniques. Treatment involves a personalized multimodal approach, including surgery, adjuvant therapies and risk stratification. Prognostic factors such as age, tumor characteristics and genetic alterations play a crucial role in determining patient outcomes. Despite advancements, gaps remain in understanding the underlying mechanisms of the disease and establishing standardized treatment guidelines. Further research, collaborative efforts and multicenter studies are necessary to improve diagnostic accuracy, develop targeted therapies and biomarkers, and enhance the long-term management. The present review provides a comprehensive overview of ATC, discussing its clinical manifestations, diagnostic approaches, treatment options, prognostic factors and genetic landscape.

Molecular signature incorporating the immune microenvironment enhances thyroid cancer outcome prediction

Genomic and transcriptomic analysis has furthered our understanding of many tumors. Yet, thyroid cancer management is largely guided by staging and histology, with few molecular prognostic and treatment biomarkers. Here, we utilize a large cohort of 251 patients with 312 samples from two tertiary medical centers and perform DNA/RNA sequencing, spatial transcriptomics, and multiplex immunofluorescence to identify biomarkers of aggressive thyroid malignancy. We identify high-risk mutations and discover a unique molecular signature of aggressive disease, the Molecular Aggression and Prediction (MAP) score, which provides improved prognostication over high-risk mutations alone. The MAP score is enriched for genes involved in epithelial de-differentiation, cellular division, and the tumor microenvironment. The MAP score also identifies aggressive tumors with lymphocyte-rich stroma that may benefit from immunotherapy. Future clinical profiling of the stromal microenvironment of thyroid cancer could improve prognostication, inform immunotherapy, and support development of novel therapeutics for thyroid cancer and other stroma-rich tumors.

Substance P and Neurokinin-1 Receptor System in Thyroid Cancer: Potential Targets for New Molecular Therapies

In recent years, numerous approaches have been developed to comprehend the molecular alterations underlying thyroid cancer (TC) oncogenesis and explore novel therapeutic strategies for TC. It is now well established that the neurokinin-1 receptor (NK-1R) is overexpressed in cancer cells and that NK-1R is essential for the viability of cancer cells. The binding of substance P (SP) to NK-1R in neoplastic cells plays a pivotal role in cancer progression by promoting neoplastic cell growth, protecting tumor cells from apoptosis, triggering invasion and metastasis through the enhanced migration of cancer cells, and stimulating endothelial cell proliferation for tumor angiogenesis. Remarkably, all types of human TC (papillary, follicular, medullary, anaplastic), as well as metastatic lesions, exhibit the overexpression of SP and NK-1R compared to the normal thyroid gland. TC cells synthesize and release SP, which exerts its multiple functions through autocrine, paracrine, intracrine, and neuroendocrine processes, including the regulation of tumor burden. Consequently, the secretion of SP from TC results in increased SP levels in plasma, which are significantly higher in TC patients compared to controls. Additionally, NK-1R antagonists have demonstrated a dose-dependent antitumor action. They impair cancer cell proliferation on one side and induce apoptosis of tumor cells on the other side. Furthermore, it has been demonstrated that NK-1R antagonists inhibit neoplastic cell migration, thereby impairing both invasiveness and metastatic abilities, as well as angiogenesis. Given the consistent overexpression of NK-1R in all types of TC, targeting this receptor represents a promising therapeutic approach for TC. Therefore, NK-1R antagonists, such as the drug aprepitant, may represent novel drugs for TC treatment.

Histological findings of thyroid cancer after lenvatinib therapy

AIMS

Lenvatinib is a multikinase inhibitor used for treating unresectable or metastatic cancers, including thyroid cancer. As total thyroidectomy followed by radioactive iodine therapy is a commonly recommended initial treatment for thyroid cancer, histological findings of the thyroid after lenvatinib therapy remain unclear. Therefore, the aim of this study was to analyse in-vivo changes in patients who underwent thyroidectomy after lenvatinib therapy.

METHODS AND RESULTS

We screened 167 patients with thyroid cancer [papillary thyroid cancer (PTC), n = 102; follicular thyroid cancer (FTC), n = 26; anaplastic thyroid cancer (ATC), n = 39] who underwent lenvatinib therapy. Among these patients, six underwent thyroidectomy (lenvatinib-treated group: PTC, n = 3; FTC, n = 1; ATC, n = 2), and the specimens were examined. Five patients with PTC who did not receive lenvatinib therapy were included for comparison (untreated group). Microvessel density (MVD) was evaluated in both groups. The PTC and FTC specimens showed relatively more ischaemic changes than ATC specimens. Coagulative necrosis and ischaemic changes in cancer cells were frequently observed. ATC specimens showed fibrosis and mild cell damage. As hypothyroidism is a common side effect of lenvatinib therapy, non-cancerous thyroid tissues were also examined. Histological findings included mild lymphocytic infiltration, lymphoid follicular formation, histiocytic reaction and follicular epithelial destruction. The MVD in lenvatinib-treated tissues was significantly lower than that in untreated tissues.

CONCLUSIONS

Lenvatinib therapy probably induces relatively specific ischaemic changes in thyroid cancer cells. Moreover, inflammatory cell infiltration and decreased MVD occur to varying degrees in non-cancerous thyroid tissue and may be related to hypothyroidism, a side effect of lenvatinib.

SPRY4 as a Potential Mediator of the Anti-Tumoral Role of Macrophages in Anaplastic Thyroid Cancer Cells

Anaplastic thyroid carcinoma (ATC) is the most lethal subtype of thyroid cancer, with high invasive and metastatic potential, not responding to conventional treatments. Its aggressiveness may be influenced by macrophages, which are abundant cells in the tumor microenvironment. To investigate the role of macrophages in ATC aggressiveness, indirect co-cultures were established between ATC cell lines and THP-1-derived macrophages. Macrophages significantly increased both the migration and invasion of T235 cells (p < 0.01; p < 0.01), contrasting with a decrease in C3948 (p < 0.001; p < 0.05), with mild effects in T238 migration (p < 0.01) and C643 invasion (p < 0.05). Flow cytometry showed upregulation of CD80 (pro-inflammatory, anti-tumoral) and downregulation of CD163 (anti-inflammatory, pro-tumoral) in macrophages from co-culture with T235 (p < 0.05) and C3948 (p < 0.05), respectively. Accordingly, we found an upregulation of secreted pro-inflammatory mediators (e.g., GM-CSF, IL-1α; p < 0.05) in C3948-macrophage co-cultures. Proteomic analysis showed the upregulation of SPRY4, an inhibitor of the MAPK pathway, in C3948 cells from co-culture. SPRY4 silencing promoted cancer cell invasion, reverting the reduced invasion of C3948 caused by macrophages. Our findings support that macrophages play a role in ATC cell aggressiveness. SPRY4 is a possible modulator of macrophage-ATC cell communication, with a tumor suppressor role relevant for therapeutic purposes.

Primary thyroid rhabdomyosarcoma in an adult: A challenging case with histomolecular diagnosis and literature review

INTRODUCTION AND IMPORTANCE

Primary thyroid sarcomas are very rare tumours, accounting for less than 1 % of all thyroid malignancies. We present the fifth case in the literature of primary thyroid rhabdomyosarcoma and the third in adults with, for the first time, an extensive molecular analysis.

CASE PRESENTATION

A 61-year-old woman presented with a rapidly progressive neck mass with extensive local invasion of the tumour.

CLINICAL DISCUSSION

Histologically, the neoplasm was composed of sheets of pleomorphic or spindle-shaped cells with eosinophilic cytoplasm and few large and very pleomorphic cells admixed with the spindle cell proliferation, without any thyroid epithelial component. Immunohistochemically, the tumour cells were positive for muscular markers and negative for epithelial and thyroid differentiation markers. Molecular tests revealed the presence of NF1, PTEN and TERT pathogenic mutations. Classifying undifferentiated neoplasm with muscular differentiation into the thyroid is challenging as many more common differential diagnoses could be favoured including anaplastic thyroid carcinoma with rhabdoid phenotype, leiomyosarcoma, and other rare sarcomas.

CONCLUSION

Primary thyroid rhabdomyosarcoma is extremely rare and can be diagnostically challenging. We emphasize the histological, immunohistochemical and molecular criteria in order to make an accurate diagnosis.

Synergic Induction of Autophagic Cell Death in Anaplastic Thyroid Carcinoma

Anaplastic thyroid carcinoma (ATC) has poor prognosis, high mortality rate and lack of effective therapy. A synergic combination of PD-L1 antibody together with cell death promoting substances like deacetylase inhibitors (DACi) and multi-kinase inhibitors (MKI) could sensitize ATC cells and promote decay by autophagic cell death. The PD-L1-inhibitor atezolizumab synergized with panobinostat (DACi) and sorafenib (MKI) leading to significant reduction of the viability, measured by real time luminescence, of three different patient-derived primary ATC cells, of C643 cells and follicular epithelial thyroid cells too. Solo administration of these compounds caused a significant over-expression of autophagy transcripts; meanwhile autophagy proteins were almost not detectable after the single administration of panobinostat, thus supporting a massive autophagy degradation process. Instead, the administration of atezolizumab caused an accumulation of autophagy proteins and the cleavage of the active caspases 8 and 3. Interestingly, only panobinostat and atezolizumab were able to exacerbate the autophagy process by increasing the synthesis, the maturation and final fusion with the lysosomes of the autophagosome vesicles. Despite ATC cells could be sensitized by atezolizumab via the cleavage of the caspases, no reduction of cell proliferation or promotion of cell death was observed. The apoptosis assay evidenced the ability of panobinostat alone and in combination with atezolizumab to induce the phosphatidil serine exposure (early apoptosis) and further the secondary necrosis. Instead, sorafenib was only able to cause necrosis. The increase of caspases activity induced by atezolizumab, the apoptosis and autophagy processes promoted by panobinostat synergize thus promoting cell death in well-established and primary anaplastic thyroid cancer cells. The combined therapy could represent a future clinical application for the treatment of such lethal and untreatable solid cancer.

A unique case of anaplastic thyroid carcinoma comprising of two distinct patterns osteoclastic variant and squamous cell carcinoma in separate lobe imitating collision tumor: A case report

Anaplastic thyroid carcinoma with two distinct morphologies in two lobes with no intermixing is very rare and not reported earlier. Furthermore, osteoclastic variant of anaplastic thyroid carcinoma as well as primary squamous cell carcinoma without any differentiated components are also very rare with only few reported cases describing their cytological features. Herein, we are reporting a unique and first case of anaplastic thyroid carcinoma comprising of two distinct patterns osteoclastic variant and squamous cell carcinoma in different lobes in a 55-years-old lady with review of literature.

Adding pieces to the puzzle of differentiated-to-anaplastic thyroid cancer evolution: the oncogene E2F7

Anaplastic Thyroid Cancer (ATC) is the most aggressive and de-differentiated subtype of thyroid cancer. Many studies hypothesized that ATC derives from Differentiated Thyroid Carcinoma (DTC) through a de-differentiation process triggered by specific molecular events still largely unknown. E2F7 is an atypical member of the E2F family. Known as cell cycle inhibitor and keeper of genomic stability, in specific contexts its function is oncogenic, guiding cancer progression. We performed a meta-analysis on 279 gene expression profiles, from 8 Gene Expression Omnibus patient samples datasets, to explore the causal relationship between DTC and ATC. We defined 3 specific gene signatures describing the evolution from normal thyroid tissue to DTC and ATC and validated them in a cohort of human surgically resected ATCs collected in our Institution. We identified E2F7 as a key player in the DTC-ATC transition and showed in vitro that its down-regulation reduced ATC cells' aggressiveness features. RNA-seq and ChIP-seq profiling allowed the identification of the E2F7 specific gene program, which is mainly related to cell cycle progression and DNA repair ability. Overall, this study identified a signature describing DTC de-differentiation toward ATC subtype and unveiled an E2F7-dependent transcriptional program supporting this process.

Neoadjuvant famitinib and camrelizumab, a new combined therapy allowing surgical resection of the primary site for anaplastic thyroid carcinoma

BACKGROUND

Anaplastic thyroid cancer (ATC) is considered the most lethal thyroid cancer, with an overall 5-year survival rate below 10%. The FDA approved a BRAF/MEK inhibitor combination for the treatment of patients with BRAF-mutated ATC. However, effective therapeutic options for patients with wild-type BRAF are lacking.

CASE

In our phase II study, patients having advanced/metastatic solid ATCs were treated with famitinib and camrelizumab, a combination therapy involving a multi-targeted kinase inhibitor and an anti-PD-1 antibody. We report a case of a patient with locally advanced unresectable ATC who underwent this combination therapy, allowing us to perform complete surgical resection followed by post-operative radiation therapy.

CONCLISION

To the best of our knowledge, this is the first report describing the use of famitinib and camrelizumab as a neoadjuvant treatment for ATC with wild-type BRAF. Clinical trial for a novel neoadjuvant approach for ATC are currently open for enrollment.

BI-847325, a selective dual MEK and Aurora kinases inhibitor, reduces aggressive behavior of anaplastic thyroid carcinoma on an in vitro three-dimensional culture

BACKGROUND

Anaplastic thyroid carcinoma (ATC) is the most aggressive subtype of thyroid cancer. In this study, we used a three-dimensional in vitro system to evaluate the effect of a dual MEK/Aurora kinase inhibitor, BI-847325 anticancer drug, on several cellular and molecular processes involved in cancer progression.

METHODS

Human ATC cell lines, C643 and SW1736, were grown in alginate hydrogel and treated with IC₅₀ values of BI-847325. The effect of BI-847325 on inhibition of kinases function of MEK1/2 and Aurora kinase B (AURKB) was evaluated via Western blot analysis of phospho-ERK1/2 and phospho-Histone H3 levels. Sodium/iodide symporter (NIS) and thyroglobulin (Tg), as two thyroid-specific differentiation markers, were measured by qRT-PCR as well as flow cytometry and immunoradiometric assay. Apoptosis was assessed by Annexin V/PI flow cytometry and BIM, NFκB1, and NFκB2 expressions. Cell cycle distribution and proliferation were determined via P16, AURKA, and AURKB expressions as well as PI and CFSE flow cytometry assays. Multidrug resistance was evaluated by examining the expression of MDR1 and MRP1. Angiogenesis and invasion were investigated by VEGF expression and F-actin labeling with Alexa Fluor 549 Phalloidin.

RESULTS

Western blot results showed that BI-847325 inhibits MEK1/2 and AURKB functions by decreasing phospho-ERK1/2 and phospho-Histone H3 levels. BI-847325 induced thyroid differentiation markers and apoptosis in ATC cell lines. Inversely, BI-847325 intervention decreased multidrug resistance, cell cycle progression, proliferation, angiogenesis, and invasion at the molecular and/or cellular levels.

CONCLUSION

The results of the present study suggest that BI-857,325 might be an effective multi-targeted anticancer drug for ATC treatment.

TGF-β, to target or not to target; to prevent thyroid cancer progression?

Thyroid cancer (TC) is a common endocrine cancer with a rising incidence. Current treatment fails to eliminate aggressive thyroid tumours, prompting an investigation into the processes that cause disease progression. In this review, we provide insight into TGF-β driven epithelial to mesenchymal transition (EMT), summarizing the current literature surrounding thyroid carcinogenesis, and discuss the potential for therapeutic strategies targeting the TGF-β signalling pathway. Understanding the underlying mechanisms that regulate cancer stem cell (CSC) growth and TGF-β signalling may provide novel therapeutic approaches for highly resistant TCs.

Intrathyroidal Plasmacytoma with Pleomorphic Multilobated Bizarre Cells: A Rare Primary Clinicopathological Presentation Mimicking Anaplastic Carcinoma of Thyroid

BACKGROUND

Plasmacytoma involving thyroid gland is infrequent and can present as either primary extramedullary plasmacytoma or secondary to multiple myeloma.

METHODS AND RESULTS

We present a case of 71 years old male who complained of a huge anterior neck swelling accompanied by dysphagia and dyspnoea. Fine needle aspiration cytology was suggestive of anaplastic carcinoma of thyroid (ATC), however, the subsequent histomorphology supported by immunohistochemistry (IHC) astoundingly favoured the diagnosis of plasmacytoma. Further evaluation revealed the presence of lymphadenopathy and single bone lesion in the present case which was rather suggestive of secondary involvement of thyroid to multiple myeloma. However, the case was unique in view of its presentation as a rapidly enlarging thyroid mass associated with stridor and cytomorphological findings which were of an undifferentiated malignancy favouring ATC. The use of a broad and judicious IHC panel clinched the final diagnosis of plasmacytoma.

CONCLUSION

The present case emphasizes the diligent use of IHC in such cases given different therapeutic and prognostic implications.

A novel prognostic model for papillary thyroid cancer based on epithelial-mesenchymal transition-related genes

BACKGROUND

The frequent incidence of postsurgical recurrence issues in papillary thyroid cancer (PTC) patients is a primary concern considering the low cancer-related mortality. Previous studies have demonstrated that epithelial-mesenchymal transition (EMT) activation is closely related to PTC progression and invasion. In this study, we aimed to develop a novel EMT signature and ancillary nomogram to improve personalized prediction of progression-free interval (PFI).

METHODS

First, we carried out a differential analysis of PTC samples and pairwise normal thyroid samples to explore the differentially expressed genes (DEGs). The intersection of the DEGs with EMT-related genes (ERGs) were identified as differentially expressed EMT-related genes (DE-ERGs). We determined PFI-related DE-ERGs by Cox regression analysis and then established a novel gene classifier by LASSO regression analysis. We validated the signature in external datasets and in multiple cell lines. Further, we used uni- and multivariate analyses to identify independent prognostic characters.

RESULTS

We identified 244 prognosis-related DE-ERGs. The 244 DE-ERGs were associated with several pivotal oncogenic processes. We also constructed a novel 10-gene signature and relevant prognostic model for recurrence prediction of PTC. The 10-gene signature had a C-index of 0.723 and the relevant nomogram had a C-index of 0.776. The efficacy of the signature and nomogram was satisfying and closely correlated with relevant clinical parameters. Furthermore, the signature also had a unique potential in differentiating anaplastic thyroid cancer (ATC) samples.

CONCLUSIONS

The novel EMT signature and nomogram are useful and convenient for personalized management for thyroid cancer.

USP26 promotes anaplastic thyroid cancer progression by stabilizing TAZ

Anaplastic thyroid cancer (ATC) is one of the most lethal and aggressive human malignancies, with no effective treatment currently available. The Hippo tumor suppressor pathway is highly conserved in mammals and plays an important role in carcinogenesis. TAZ is one of major key effectors of the Hippo pathway. However, the mechanism supporting abnormal TAZ expression in ATC remains to be characterized. In the present study, we identified USP26, a DUB enzyme in the ubiquitin-specific proteases family, as a bona fide deubiquitylase of TAZ in ATC. USP26 was shown to interact with, deubiquitylate, and stabilize TAZ in a deubiquitylation activity-dependent manner. USP26 depletion significantly decreased ATC cell proliferation, migration, and invasion. The effects induced by USP26 depletion could be rescued by further TAZ overexpression. Depletion of USP26 decreased the TAZ protein level and the expression of TAZ/TEAD target genes in ATC, including CTGF, ANKRD1, and CYR61. In general, our findings establish a previously undocumented catalytic role for USP26 as a deubiquitinating enzyme of TAZ and provides a possible target for the therapy of ATC.

Osteoclastic variant of anaplastic thyroid carcinoma: An insight into a rarest of rare entity

Anaplastic thyroid carcinoma is a rare and a very aggressive thyroid malignancy with a dismal prognosis. It has a short history and presents with a rapidly increasing neck mass associated with compressive symptoms like pain, hoarseness of voice, dysphagia and shortness of breath. Osteoclastic variant is an extremely rare variant, which is, characterize by presence of a large number of multinucleated giant cells, which resemble osteoclasts. Here we report two cases of this unusual variant in a 68 years old and 49 years old male with a short history of thyroid swelling.

Long non-coding RNA CATIP antisense RNA 1 (lncRNA CATIP-AS1) downregulation contributes to the progression and metastasis of thyroid cancer via epithelial-mesenchymal transition (EMT) pathway

Thyroid cancer (THCA) is the most common cancer of the endocrine system across the globe. To date, the mechanism of development of THCA remains scarcely known. In this study, we aim to elucidate the long non-coding RNA CATIP antisense RNA 1 (lncRNA CATIP-AS1/CATIP-AS1) role in the pathogenesis of THCA and its regulatory mechanism. The result shows that the CATIP-AS1 was significantly downregulated in THCA tissues and cells and was associated with a poor prognosis of patients diagnosed with THCA. The overexpression of CATIP-AS1 significantly inhibited THCA cell proliferation, migration, and epithelial–mesenchymal transition (EMT) but increased the THCA cell apoptosis. We found that CATIP-AS1 endogenously sponges miR-515-5p and its overexpression could inhibit miR-515-5p regulatory effect. Moreover, the overexpression of miR-515-5p repressed the Smad4 expression level, consequently reversed the inhibiting effect of overexpressed CATIP-AS1 on the proliferation, and migration of THCA cell. It also reversed the increased THCA cell apoptosis and the downregulated-CATIP-AS1-induced cell EMT inhibition. Summarily, we demonstrated that the CATIP-AS1 promotes the progression and metastasis of THCA via EMT pathway partly through regulating the miR-515-5p and Smad4 expression in THCA cell. The CATIP-AS1 could be a promising biomarker for early THCA detection and prognosis and a possible therapeutic target for its treatment.

Anaplastic thyroid carcinoma in a brush-tailed rock-wallaby (Petrogale penicillata)

Background

Neoplasia is considered to be rare in macropods. Anaplastic thyroid carcinoma (ATC) also known as undifferentiated or giant cell carcinoma, is a rare but aggressive and lethal solid tumour reported to affect humans, dogs, cats, racoons and birds. It is derived from poorly differentiated follicular cells and lacks the characteristic architectural pattern of arrangement of tumour cells. ATC has not previously been reported in macropods.

Case Report

A brush‐tailed rock‐wallaby (Petrogale penicillata) was presented for a mass on the ventral neck. A clinical diagnosis of thyroid carcinoma was suspected based on radiology, ultrasound and cytology. Other than palliative care, treatment was declined. Four months later the wallaby was found dead and submitted for necropsy. Gross examination and histopathology demonstrated a unilateral ATC with vascular neoplastic emboli and distant metastases to the heart, lungs and liver.

Conclusion

The clinical signs associated with thyroid tumours may be the result of localised growth and expansion of the thyroid, metastatic disease or a combination of these effects. Most thyroid tumours are nonfunctional. Based on the lack of typical clinical signs associated with functional thyroid tumours, in this case, we conclude that the thyroid tumour in this wallaby was likely to be nonfunctional. The cause of death in this wallaby was likely due to the heavy tumour burden with compromised cardiorespiratory function exacerbated by dorsoventral compression of the larynx. More study is needed to better understand thyroid neoplasia in macropods.

Flurbiprofen inhibits cell proliferation in thyroid cancer through interrupting HIP1R-induced endocytosis of PTEN

Background

The incidence of thyroid cancer, a most common tumor in the endocrine system, has increased in recent years. A growing number of studies have focused on the molecular mechanisms of thyroid cancer subtypes, aiming to identify effective therapeutic targets. Endocytosis is of vital significance in the malignant development of tumors, although its involvement in thyroid cancer has been rarely reported.

Methods

HIP1R expressions in thyroid cancer from the TCGA database were analyzed by UALCAN software. Thyroid epithelial and cancer cell lines were cultured in vitro. Western blotting and quantitative PCR were used to analyze protein and mRNA levels, respectively. Cell viability was measured by CCK-8 assay. Immunofluorescence staining indicated protein distribution in cell. Co-immunoprecipitation was used to study protein–protein interaction. Immunohistochemical staining was used to analyze protein expression in clinical tissues. Differences between groups were compared using the two-tailed Student’s t test, and those among three or more groups were compared by one-way or two-way ANOVA.

Results

In the present study, HIP1R (Huntingtin Interacting Protein 1 Related) was found upregulated in thyroid cancer tissues and cell lines compared with that in the controls, while knockdown of HIP1R significantly inhibited the proliferation of thyroid cancer cells. Since HIP1R is essential for the clathrin-dependent endocytic process, we thereafter explored the effect of HIP1R on the endocytosis of thyroid cancer cells. Interestingly, knockdown of HIP1R significantly reduced the number of clathrin-coated pits (CCPs) in thyroid cancer cells. In addition, the interaction between HIP1R and PTEN (phosphatase and tensin homolog) was identified in thyroid cancer cells. Knockdown of HIP1R downregulated intracellular PTEN in thyroid cancer cells, but upregulated membrane-binding PTEN. Notably, flurbiprofen, a commonly used analgesic, significantly inhibited the proliferation of thyroid cancer cells and interfered with the interaction between HIP1R and PTEN, thereby enhancing the binding of PTEN to cell membrane. However, the proliferation inhibitory effect of flurbiprofen was attenuated when knocking down HIP1R or PTEN.

Conclusions

Upregulated HIP1R in thyroid cancer cells promotes cell proliferation and mediates the endocytosis of PTEN. Flurbiprofen may exert an anti-tumor effect on thyroid cancer by blocking the interaction between HIP1R and PTEN.

Anaplastic Thyroid Carcinoma: An Update

Anaplastic thyroid carcinoma (ATC) is a rare and undifferentiated form of thyroid cancer. Its prognosis is poor: the median overall survival (OS) of patients varies from 4 to 10 months after diagnosis. However, a doubling of the OS time may be possible owing to a more systematic use of molecular tests for targeted therapies and integration of fast-track dedicated care pathways for these patients in tertiary centers. The diagnostic confirmation, if needed, requires an urgent biopsy reread by an expert pathologist with additional immunohistochemical and molecular analyses. Therapeutic management, defined in multidisciplinary meetings, respecting the patient's choice, must start within days following diagnosis. For localized disease diagnosed after primary surgical treatment, adjuvant chemo-radiotherapy is recommended. In the event of locally advanced or metastatic disease, the prognosis is very poor. Treatment should then involve chemotherapy or targeted therapy and decompressive cervical radiotherapy. Here we will review current knowledge on ATC and provide perspectives to improve the management of this deadly disease.

Collision tumor of the thyroid - a challenge during the COVID-19 pandemic

Some of the patients with anaplastic thyroid carcinomas have a coexistent differentiated thyroid cancer, sustaining the hypothesis that this cancer may develop from more differentiated tumors. We describe a case with a collision tumor of the thyroid, defined as a neoplastic lesion composed of two distinct cell populations, with distinct borders. The patient presented during the COVID-19 pandemic with dysphonia, dyspnea, multinodular goiter and a painless, rapidly enlarging, left cervical swelling. She had been first time diagnosed with left nodular goiter in 2007, with an indication for surgery, which she declined. After partial excision of the left latero-cervical adenopathy, the pathological analysis showed massive lymph node metastasis from anaplastic thyroid cancer. A total thyroidectomy was done; the postoperative pathological exam identified a papillary thyroid microcarcinoma in the right lobe and an anaplastic thyroid cancer in the left lobe. Postoperatively, levothyroxine treatment was started and the patient was referred to radiotherapy. This case highlights the importance of urgent management of some cases with compressive multinodular goiter, even during the COVID-19 pandemic.

Dabrafenib plus trametinib in patients with BRAF V600E–mutant anaplastic thyroid cancer: updated analysis from the phase II ROAR basket study

Background:

Combined therapy with dabrafenib plus trametinib was approved in several countries for treatment of BRAF V600E-mutant anaplastic thyroid cancer (ATC) based on an earlier interim analysis of 23 response-assessable patients in the ATC cohort of the phase II Rare Oncology Agnostic Research (ROAR) basket study. We report an updated analysis describing the efficacy and safety of dabrafenib plus trametinib in the full ROAR ATC cohort of 36 patients with ~4 years of additional study follow-up.

Patients and methods:

ROAR (NCT02034110) is an open-label, nonrandomized, phase II basket study evaluating dabrafenib plus trametinib in BRAF V600E-mutant rare cancers. The ATC cohort comprised 36 patients with unresectable or metastatic ATC who received dabrafenib 150 mg twice daily plus trametinib 2 mg once daily orally until disease progression, unacceptable toxicity, or death. The primary endpoint was investigator-assessed overall response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1. Secondary endpoints were duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety.

Results:

At data cutoff (14 September 2020), median follow-up was 11.1 months (range, 0.9–76.6 months). The investigator-assessed ORR was 56% (95% confidence interval, 38.1% to 72.1%), including three complete responses; the 12-month DOR rate was 50%. Median PFS and OS were 6.7 and 14.5 months, respectively. The respective 12-month PFS and OS rates were 43.2% and 51.7%, and the 24-month OS rate was 31.5%. No new safety signals were identified with additional follow-up, and adverse events were consistent with the established tolerability of dabrafenib plus trametinib.

Conclusions:

These updated results confirm the substantial clinical benefit and manageable toxicity of dabrafenib plus trametinib in BRAF V600E-mutant ATC. Dabrafenib plus trametinib notably improved long-term survival and represents a meaningful treatment option for this rare, aggressive cancer.

A mediastinal malignant thyroid paraganglioma: A case report and literature review

Introduction and importance

Thyroid cancer is the most common endocrine malignancy, while primary paraganglioma of the thyroid gland (TP) is an unusual tumour and in rare cases, this disease tends to mimic thyroid cancer. They are rare extra-adrenal neuroendocrine tumours originating from the neural crest, and are found almost exclusively in the head and neck area.

Case presentation

We present a case of a 53-year-old man, in whom a mediastinal lesion originating from the left lobe of the thyroid gland was found on routine ultrasound and subsequent computed tomography (CT).

Clinical discussion

Total thyroidectomy and lymph dissection were performed. A review of the literature was made and a discussion was held regarding the diagnosis, the importance of surgical treatment and further behaviour.

Conclusion

Surgical removal of the thyroid gland is the main treatment, followed by radiation therapy. The diagnosis and differential diagnosis with other thyroid tumours is extremely important in terms of subsequent behaviour and prognosis.

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Lesions like the one we described should be operated on.

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Examination of surgical specimen is more accurate than transcutaneous biopsy.

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Cervicotomy is an appropriate approach but extension to sternotomy could occur.

Epstein-Barr Virus-Associated Gastric Cancer: Old Entity with New Relevance

Gastric cancer (GC) represents a major public health issue worldwide, being the fifth most common cancer and one of the leading causes of death by cancer. In 2014, The Cancer Genome Atlas (TCGA) established that tumors positive for Epstein-Barr virus (EBV) are considered a specific subtype of GC (EBVaGC). Several meta-analyses have shown that EBVaGC represents almost 10% of all gastric cancer worldwide, with small differences in the geographic distribution. This tumor subtype has a high potential of being clinically relevant and studies have shown that it has specific features, a better prognosis, and increased overall survival. In this review, we summarize some of the most frequent aspects of EBVaGC, including the specific features of this GC subtype, data regarding the potential steps of EBVaGC carcinogenesis, and perspectives on treatment opportunities.

Is it Anaplastic Thyroid Cancer, Primary Thyroid Lymphoma, or Rosai Dorfman Disease? An Elusive Histopathologic Diagnosis of a Thyroid Mass

The aim of this study is to present an elusive case of primary thyroid lymphoma (PTL), initially thought to be anaplastic thyroid carcinoma, then Rosai Dorfman disease, before the final diagnosis of PTL was made. An elderly female with hypothyroidism presented with compressive airway symptoms secondary to an enlarging neck mass. Imaging was suggestive of undifferentiated thyroid cancer. The initial biopsy was unexpectedly consistent with a lymphoproliferative disorder such as Rosai-Dorfman disease. A repeat biopsy with immunohistochemical analysis yielded a diagnosis of diffuse large B-cell lymphoma of germinal center subtype. The patient was spared thyroid surgery and started on appropriate chemotherapy. PTL is within the differential diagnosis that physicians must consider in a patient with a rapidly-enlarging neck mass. A clinical index of suspicion and early accurate diagnosis may spare the patient from unnecessary surgery that is required of most other non-hematopoeitic thyroid malignancies.

Solid Thyroid Follicular Nodules With Longitudinal Nuclear Grooves: Clinicopathologic, Immunohistochemical, and Molecular Genetic Study of 18 Cases

CONTEXT.—

Follicular thyroid nodules can be a source of diagnostic difficulties, particularly when they display atypical features commonly associated with malignancy, such as nuclear grooves.

OBJECTIVE.—

To differentiate lesions with atypical features from similar-appearing benign and malignant lesions.

DESIGN.—

Eighteen cases of atypical follicular thyroid nodules characterized by a solid growth pattern and prominent longitudinal nuclear grooves were studied and examined for clinicopathologic characteristics.

RESULTS.—

The lesions occurred in 16 women and 2 men aged 36 to 88 years and measured from 0.2 to 1.5 cm. The tumors were well circumscribed and noninvasive, and histologically characterized by a predominantly solid growth pattern with rare scattered follicles or a combination of solid growth pattern with minor follicular areas. A striking feature seen in all cases was the occurrence of longitudinal nuclear grooves. Immunohistochemical stains showed negativity for cytokeratin 19 (CK19) and HBME-1 in 8 cases; in the other 10, there was focal positivity for HBME-1 in 4 cases and diffuse positivity in 6. All cases were negative for galectin-3 and for CK19, with the exception of 1 case, which was CK19+/HBME-1-. Next-generation sequencing of 16 cases with a 161-gene panel detected 14 single nucleotide variants in 12 cases, predominantly NRAS and HRAS mutations. Clinical follow-up ranging from 18 to 72 months (median, 43.7 months) did not disclose any evidence of recurrence or metastases.

CONCLUSIONS.—

We interpret these lesions as low-grade, indolent follicular proliferations that need to be distinguished from papillary thyroid carcinoma, follicular adenoma, and noninvasive follicular thyroid neoplasms with papillary-like nuclear features.

Dramatic clinical response to dabrafenib plus trametinib in anaplastic thyroid carcinoma and the challenges faced during the COVID-19 pandemic

Anaplastic thyroid carcinoma is the rarest tumor of the thyroid gland, representing less than 2% of clinically recognized thyroid cancers. Typically, it has an extremely rapid onset, fatal outcomes in most cases, and a median overall survival of 3 to 10 months despite aggressive multidisciplinary management. The presence of targetable mutations in anaplastic thyroid carcinoma patients is an opportunity for treatment when conventional therapeutics approaches are not effective, a frequent situation in the majority of patients. We present our experience in the management of a patient with unresectable anaplastic thyroid cancer who had a remarkable and rapid response to treatment with dabrafenib and trametinib during the COVID-19 pandemic. After four weeks of dabrafenib 150 mg twice daily plus trametinib 2 mg daily, he showed a dramatic reduction of the cervical mass around 90%. Nearly eight weeks under treatment with dabrafenib plus trametinib, the patient remains with minimal locoregional disease without distant metastases.

Papillary Thyroid Carcinoma with Desmoid-Type Fibromatosis: Review of Published Cases

Simple Summary

Papillary thyroid cancer (PTC)-desmoid type fibromatosis (DTF) is one of the rarest variants of PTC. The diagnosis is histological, and detecting a mutation of CTNNB1 in the mesenchymal component is highly suggestive of PTC-DTF. The treatment is essentially surgical. We conducted a review of all cases of PTC-DTF found in the English literature and our aim is to describe patient’s characteristics, histology, immunohistochemistry and somatic mutations of every case.

Abstract

Desmoid-type fibromatosis (DTF) is a very rare variant of papillary thyroid carcinoma (PTC). It is essentially a dual tumor with a component of classical PTC with malignant epithelial proliferation (BRAF-mutated) and another component of mesenchymal proliferation (CTNNB1-mutated). We conducted a literature review on PTC-DTF. In total, 31 articles were identified, that together reported on 54 patients. The mean age was 47 years, with a 2.2:1 female predominance. No ultrasound features were found to be helpful in differentiating PTC-DTF from other PTC variants. Of the 43 cases that reported histological details, 60% had locally infiltrative disease (T3b or T4). Around 48% had cervical lymph node metastases, but none had distant metastases. While PTC-DTF may be locally more aggressive than classic PTC, its overall behavior is similar and can include extrathyroidal extension and lymph node metastases, which may contain a stromal component and show extranodal invasion. The mainstay of treatment for PTC-DTF is surgery, and the DTF component is not expected to be sensitive to radioactive iodine. External radiotherapy, non-steroidal anti-inflammatory drugs, tyrosine kinase inhibitors and chemotherapy have also been used in selected cases. Due to the rarity of these tumors and the lack of specific treatment guidelines, management should be discussed in a multidisciplinary team.

Prognostic Role of Pre-Treatment [18F]FDG PET/CT in Patients with Anaplastic Thyroid Cancer

Simple Summary

This study evaluates the prognostic capability of the ¹⁸fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography (PET)/computed tomography (CT) in patients with anaplastic thyroid cancer (ATC) which can be used as a potential biomarker reflecting glycolysis. ATC is a rare, but highly lethal disease with a one-year overall survival of 20%, and its prognostic factors have rarely been investigated. In this study, survival data correlated with PET/CT derived parameters provide evidence that FDG uptake assessed by PET/CT is a prognostic marker, which may have a clinical impact on the management of patients with ATC.

Abstract

Anaplastic thyroid carcinoma (ATC) is a rare but highly lethal disease. Therefore, its diagnosis at an early stage and a rapid and accurate establishment of a proper treatment strategy is warranted. Tumor glycolysis assessed by ¹⁸fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography (PET)/computed tomography (CT) is predictive of many cancers despite its limited proven applicability to ATC. We investigated the prognostic capability of [¹⁸F]FDG PET/CT in patients with ATC. Forty patients with ATC were subjected to [¹⁸F]FDG PET/CT for pre-treatment evaluation. The tumor size and stage, overall survival (OS), and PET parameters, including the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were analyzed. The 1-year OS rate was 17.5% with a mean life expectancy of 7.1 months. Distant metastasis was detected solely using PET/CT in 37.5% of cases. High SUVmax, MTV, and TLG were significantly associated with poor prognosis (p < 0.001, p = 0.002, and p < 0.001, respectively). A significant difference (p < 0.001) was observed in OS between patients with a high and low tumor SUVmax. Glucose metabolism assessed by [¹⁸F]FDG PET/CT was significantly associated with the OS of patients with ATC. PET-derived parameters such as SUVmax, MTV, and TLG are useful prognostic biomarkers for ATC.

Sarcomatoid hepatocellular carcinoma is distinct from ordinary hepatocellular carcinoma: Clinicopathologic, transcriptomic and immunologic analyses

Sarcomatoid hepatocellular carcinoma (SHCC), which was a rare histological subtype of hepatocellular carcinoma (HCC), is currently subclassified as poorly differentiated HCC because of insufficient evidence to define SHCC as a subtype of HCC. We aimed to assess the feasibility of classifying SHCC as a histological subtype of HCC by comprehensively identifying novel and distinct characteristics of SHCC compared to ordinary HCC (OHCC). Fifteen SHCCs (1.4%) defined as HCC with at least a 10% sarcomatous component, 15 randomly disease-stage-matched OHCCs and 163 consecutive OHCCs were extracted from 1106 HCCs in the Pathology Database (1997-2019) of our hospital. SHCC patients showed poor prognosis, and the tumors could be histologically subclassified into the pleomorphic, spindle and giant cell types according to the subtype of carcinomas with sarcomatoid or undifferentiated morphology in other organs. The transcriptomic analysis revealed distinct characteristics of SHCC featuring the upregulation of genes associated with epithelial-to-mesenchymal transition and inflammatory responses. The fluorescent multiplex immunohistochemistry results revealed prominent programmed death-ligand 1 (PD-L1) expression on sarcomatoid tumor cells and higher infiltration of CD4⁺ and CD8⁺ T cells in SHCCs compared to OHCCs. The density of CD8⁺ T cells in the nonsarcomatous component of SHCCs was also higher than that in OHCCs. In conclusion, the comprehensive analyses in our study demonstrated that SHCC is distinct from OHCC in terms of clinicopathologic, transcriptomic and immunologic characteristics. Therefore, it is reasonable to consider SHCC as a histological subtype of HCC.

Gold-Based Nanoplataform for the Treatment of Anaplastic Thyroid Carcinoma: A Step Forward

Anaplastic thyroid carcinoma (ATC) is a very rare subtype of thyroid carcinoma and one of the most lethal malignancies. Poor prognosis is mainly associated with its undifferentiated nature, inoperability, and failing to respond to the typically used therapies for thyroid cancer. Photothermal Therapy (PTT) entails using light to increase tissues' temperature, leading to hyperthermia-mediated cell death. Tumours are more susceptible to heat as they are unable to dissipate it. By using functionalized gold nanoparticles (AuNPs) that transform light energy into heat, it is possible to target the heat to the tumour. This study aims to formulate ATC-targeted AuNPs able to convert near-infrared light into heat, for PTT of ATC. Different AuNPs were synthetized and coated. Size, morphology, and surface plasmon resonances band were determined. The optimized coated-AuNPs were then functionalized with ligands to assess ATC's specificity. Safety, efficacy, and selectivity were assessed in vitro. The formulations were deemed safe when not irradiated (>70% cell viability) and selective for ATC. However, when irradiated, holo-transferrin-AuNPs were the most cytotoxic (22% of cell viability). The biodistribution and safety of this formulation was assessed in vivo. Overall, this novel formulation appears to be a highly promising approach to evaluate in a very near future.

High-grade mucoepidermoid carcinoma in the thyroid gland with poor prognosis

Mucoepidermoid carcinoma (MEC) is the most common malignant neoplasm of the salivary gland, but primary thyroid MEC has rarely been reported and usually has a good prognosis. Herein, I report a case of thyroidal MEC with a poor prognosis in an 82-year-old woman with an anterior neck mass. Ultrasonography and computed tomography revealed a thyroid mass. The patient initially underwent fine-needle aspiration, was diagnosed with malignancy, and underwent a right lobectomy. On gross examination, a 4.0×3.6×2.6 cm-sized ill-defined, unencapsulated, and infiltrative tan to whitish mass with necrosis was identified. Microscopically, epidermoid tumor cell nests or solid sheets were identified. Mucous cells that were positive for periodic acid-Schiff and mucicarmine stains were also identified within epidermoid cell nests. Frequent mitosis and necrosis were observed. Immunohistochemical staining for p40 and p63 was positive, and that for thyroid transcription factor-1 and paired box gene 8 was focally positive. According to the Armed Forces Institute of Pathology grading system for salivary gland MEC, the current case was classified as high-grade MEC. After surgery, the patient suffered from dyspnea due to a remnant neck mass that compressed and obstructed the trachea; therefore, the patient refused further treatment. Thyroidal MECs are considered low-grade with a favorable prognosis, but there are several reported cases of thyroidal MEC with poor prognosis. The current case is a rare presentation of high-grade thyroidal MEC with a poor prognosis.

2021 American Thyroid Association Guidelines for Management of Patients with Anaplastic Thyroid Cancer

Background: Anaplastic thyroid cancer (ATC) is a rare but highly lethal form of thyroid cancer. Since the guidelines for the management of ATC by the American Thyroid Association were first published in 2012, significant clinical and scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, and researchers on published evidence relating to the diagnosis and management of ATC. Methods: The specific clinical questions and topics addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of the Task Force members (authors of the guideline). Relevant literature was reviewed, including serial PubMed searches supplemented with additional articles. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations. Results: The guidelines include the diagnosis, initial evaluation, establishment of treatment goals, approaches to locoregional disease (surgery, radiotherapy, targeted/systemic therapy, supportive care during active therapy), approaches to advanced/metastatic disease, palliative care options, surveillance and long-term monitoring, and ethical issues, including end of life. The guidelines include 31 recommendations and 16 good practice statements. Conclusions: We have developed evidence-based recommendations to inform clinical decision-making in the management of ATC. While all care must be individualized, such recommendations provide, in our opinion, optimal care paradigms for patients with ATC.

TMEM158 May Serve as a Diagnostic Biomarker for Anaplastic Thyroid Carcinoma: An Integrated Bioinformatic Analysis

Anaplastic thyroid carcinoma (ATC) is a rare but extremely lethal malignancy. However, little is known about the pathogenesis of ATC. Given its high mortality, it is critical to improve our understanding of ATC pathogenesis and to find new diagnostic biomarkers. In the present study, two gene microarray profiles (GSE53072 and GSE65144), which included 17 ATC and 17 adjacent non-tumorous tissues, were obtained. Bioinformatic analyses were then performed. Immunohistochemistry (IHC) and receiver operating characteristic (ROC) curves were then used to detect transmembrane protein 158 (TMEM158) expression and to assess diagnostic sensitivity. A total of 372 differentially expressed genes (DEGs) were identified. Through protein-protein interaction (PPI) analysis, we identified a significant module with 37 upregulated genes. Most of the genes in this module were related to cell-cycle processes. After co-expression analysis, 132 hub genes were selected for further study. Nine genes were identified as both DEGs and genes of interest in the weighted gene co-expression network analysis (WGCNA). IHC and ROC curves confirmed that TMEM158 was overexpressed in ATC tissue as compared with other types of thyroid cancer and normal tissue samples. We identified 8 KEGG pathways that were associated with high expression of TMEM158, including aminoacyl-tRNA biosynthesis and DNA replication. Our results suggest that TMEM158 may be a potential oncogene and serve as a diagnostic indicator for ATC.

Comprehensive guidance on the diagnosis and management of primary mesenchymal tumours of the thyroid gland

Most primary thyroid tumours are of epithelial origin. Primary thyroid mesenchymal tumours are rare but are being increasingly detected. A vast majority of thyroid mesenchymal tumours occur between the fourth and seventh decades of life, presenting as progressively enlarging thyroid nodules that often yield non-diagnostic results or spindle cells on fine needle aspiration biopsy. Surgery is the preferred mode of treatment, with adjuvant chemoradiotherapy used for malignant thyroid mesenchymal tumours. Benign thyroid mesenchymal tumours have excellent prognosis, whereas the outcome of malignant thyroid mesenchymal tumours is variable. Each thyroid mesenchymal tumour is characterised by its unique histopathology and immunohistochemistry. Because of the rarity and aggressive nature of malignant thyroid mesenchymal tumours, a multidisciplinary team-based approach should ideally be used in the management of these tumours. Comprehensive guidelines on the management of thyroid mesenchymal tumours are currently lacking. In this Review, we provide a detailed description of thyroid mesenchymal tumours, their clinical characteristics and tumour behaviour, and provide recommendations for the optimal management of these tumours.