Poorly differentiated carcinoma of the thyroid: validation of the Turin proposal and analysis of IMP3 expression

Ultrasound and histopathological assessment of benign, borderline, and malignant thyroid tumors in pediatric patients: an illustrative review and literature overview

Background

The risk of malignancy in thyroid nodules is higher in children than in adults, often necessitating a more aggressive endocrine and surgical approach. However, given that not all solid thyroid nodules are malignant, a more conservative approach may also be appropriate in certain cases.

Objective

This study aims to present an illustrative analysis of the pathological foundations underlying the sonographic appearance of benign, borderline, and malignant thyroid nodules in the pediatric population at a single tertiary thyroid center.

Methods

A total of 47 well-documented pediatric patients referred for thyroid surgery between 2010 and 2023 were analyzed. This retrospective assessment included an examination of demographic data, hormonal profiles, ultrasound findings, and histopathology reports.

Results

Ultrasound and histopathology of thyroid nodules provided insights into subgroup differentiation. Benign nodules like dyshormonogenetic goiter showed solid hypoechoic features on ultrasound and dense fibrosis on histopathology, while thyroid follicular nodular disease exhibited isoechoic nodules with halos, histologically revealing dilated follicles. In borderline tumors, well-differentiated tumor of uncertain malignant potential (WDT-UMP) nodules were hypo/hyperechoic with occasional capsular invasion, resembling papillary thyroid carcinoma (PTC) features histologically. Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) appeared as well-defined hypoechoic nodules with a hypoechoic rim, with histology showing follicular architecture and PTC nuclear features, but no invasion. Follicular tumor of uncertain malignant potential (FT-UMP) displayed hypo/hyperechoic patterns and indistinct borders, with uncertain capsular invasion and no PTC nuclear features. Malignant lesions showed distinct patterns: PTC as hypoechoic, irregular nodules with mixed vascularization, follicular thyroid carcinoma as large, hyperechoic nodules with invasive features, and poorly differentiated thyroid carcinoma (PDTC) as heterogeneous hypoechoic masses.

Conclusion

Because of the significant overlap in sonographic features among benign, borderline, and certain malignant thyroid lesions in pediatric patients, ultrasonography alone is insufficient for accurate risk stratification. This overlap necessitates referrals for fine-needle aspiration biopsy (FNAB) in children more frequently than in adults. Future studies utilizing artificial intelligence (AI) to predict clinical outcomes in thyroid nodule diagnostics may offer new advancements, particularly given the increasing number of pediatric patients with solid thyroid lesions.

Prognostic impact of fibrosclerotic changes in non-papillary, non-anaplastic, follicular cell-derived thyroid carcinomas

In non-papillary follicular cell-derived thyroid carcinomas, prognostic factors are scarce. Intratumoral fibrosis was identified as an adverse factor in papillary and medullary carcinomas, but it has not been investigated in other subtypes. We aimed at exploring the presence of intratumoral fibrosclerosis in a cohort of 132 non-papillary follicular cell-derived thyroid carcinomas (53 follicular and 31 oncocytic carcinomas, including 10 high grade differentiated thyroid carcinomas and 48 poorly differentiated carcinomas) and correlating its presence and extent with clinical and pathological features and survival. For each case, all available hematoxylin and eosin slides were reviewed, and the presence of fibrosclerosis was assessed as the percentage of tumor area and semi-quantitatively scored as absent, mild (≤ 10%) or extensive (> 10%). In addition, digital image analysis was applied in 65 cases. Scoring of intratumoral fibrosis showed a strong agreement between two observers and between observers and digital image quantification. The presence and extent of intratumoral fibrosis were significantly associated with poorly differentiated carcinoma histology, large tumor size, extent of vascular invasion, presence of necrosis, high mitotic index, positive nodal status, and aggressive clinical outcome, and with a shorter disease-free and disease-specific survival, the former also in follicular and oncocytic carcinomas analyzed separately. These data support the potential use of fibrosis in the clinical practice since it is both easily assessable and significantly associated with the presence of parameters of aggressiveness. In addition, fibrosis is correlated with decreased survival rate independently from the tumor histotypes, suggesting its potential role as novel prognostic factor in non-papillary follicular cell-derived thyroid carcinomas.

Low Mitotic Activity in Papillary Thyroid Cancer: A Marker for Aggressive Features and Recurrence

CONTEXT

The significance of low mitotic activity in papillary thyroid cancer (PTC) is largely undefined.

OBJECTIVE

We aimed to determine the behavioral landscape of PTC with low mitotic activity compared with that of no and high mitotic activity.

METHODS

A single-institution consecutive series of patients with PTC from 2018 to 2022 was reviewed. Mitotic activity was defined as no mitoses, low (1-2 mitoses/2 mm2) or high (≥3 mitoses/2 mm2) per the World Health Organization. The 2015 American Thyroid Association risk stratification was applied to the cohort, and clinicopathologic features were compared between groups. For patients with ≥6 months of follow-up, Cox regression analyses for recurrence were performed.

RESULTS

A total of 640 PTCs were included-515 (80.5%) no mitotic activity, 110 (17.2%) low mitotic activity, and 15 (2.3%) high mitotic activity. Overall, low mitotic activity exhibited rates of clinicopathologic features including vascular invasion, gross extrathyroidal extension, and lymph node metastases in between those of no and high mitotic activity. PTCs with low mitotic activity had higher rates of intermediate- and high-risk American Thyroid Association (ATA) risk stratification compared with those with no mitotic activity (P < .001). Low mitotic activity PTCs also had higher recurrence rates (15.5% vs 4.5%, P < .001). Low mitotic activity was associated with recurrence, independent of the ATA risk stratification (HR 2.96; 95% CI 1.28-6.87, P = .01).

CONCLUSION

Low mitotic activity is relatively common in PTC and its behavior lies within a spectrum between no and high mitotic activity. Given its association with aggressive clinicopathologic features and recurrence, low mitotic activity should be considered when risk stratifying patients with PTC for recurrence.

Nano-approaches and Recent Advancements in Strategies to Combat Challenges Associated with Thyroid Cancer Therapies

The prevalence of thyroid cancer (TC) is more common in women and is up to 43% in patients aged between 45-65 years. The battle against TC is hampered by the lack of effective diagnostic and therapeutic approaches. The effectiveness of surgical procedures, such as thyroidectomy and nutraceutical treatments, are accompanied by several difficulties and still require further research. Alternatively, the DNA-damaging traditional model of chemotherapy is linked to poor solubility, untoward systemic effects, and associated cytotoxicity, instituting an urgent need to establish a specialized, factual, and reliable delivery tool. In order to overcome the limitations of conventional delivery systems, nanotechnology-based delivery tools have shown the potential of articulating endless inherent implementations. The probable benefits of emerging nanotechnology-based diagnostic techniques include rapid screening and early illness diagnosis, which draws investigators to investigate and assess the possibility of this treatment for TC. Subsequently, organic (e.g., liposomes, polymer-based, and dendrimers) and inorganic (e.g., gold, carbon-based, mesoporous silica, magnetic, and quantum dots) NPs and hybrids thereof (liposome-silica, chitosan-carbon, and cell membrane-coated) have been projected for TC biomarker screening, therapy, and detection, providing better outcomes than traditional diagnostic and treatment techniques. Therefore, this review aims to offer a broad perspective on nanoplatform in TC, accompanied by present and potential future treatment options and screening techniques; including the innovative patents utilized in the realm of thyroid cancer using nanocarriers. The goal of cancer therapy has traditionally been to "search a thorn in a hayloft"; therefore, this article raises the possibility of treating TC using nano-oncotherapeutics, which might be useful clinically and will encourage future researchers to explore this tool's potential and drawbacks.

Clinicopathologic and Molecular Analysis of 15 Pediatric and Young Adult Patients with High-Grade Non-anaplastic Thyroid Carcinoma

High-grade follicular cell-derived non-anaplastic thyroid carcinomas are uncommon and typically diagnosed in the sixth to seventh decade of life. These tumors are rare in the pediatric (≤ 18 years old) and young adult (19-21 years old) populations. The molecular landscape of pediatric and young adult thyroid neoplasia has been suggested to be enriched in DICER1 gene alterations. Our intent was to evaluate pediatric and young adult high-grade follicular cell-derived non-anaplastic thyroid carcinomas for driver mutations. Thyroid carcinomas involving individuals under the age of 21 years were retrieved from our institutional archives. The patient population included 13 females and 2 males aged 9-20 years. Six patients were aged 9-16 years and nine patients were aged 19-20 years. The carcinomas were classified as poorly differentiated thyroid carcinoma (PDTC) (n = 6) and differentiated high-grade thyroid carcinoma (DHGTC) (n = 9). Two were poorly differentiated oncocytic thyroid carcinomas, and two were poorly differentiated follicular thyroid carcinomas. A well-differentiated component was not identified in 2 PDTCs. The DHGTCs were subclassified as follicular thyroid carcinoma (n = 4), classic subtype papillary thyroid carcinoma (n = 4), and oncocytic thyroid carcinoma (n = 1). Molecular evaluation revealed one differentiated high-grade follicular thyroid carcinoma, two poorly differentiated follicular thyroid carcinomas, and two PDTCs with DICER1 gene alterations. A DICER1-altered PDTC, DICER1-altered poorly differentiated follicular thyroid carcinoma, and a poorly differentiated oncocytic thyroid carcinoma had TP53 gene alterations. BRAF V600E immunohistochemistry (IHC) was positive in two cases. PanTRK IHC was positive in two cases, one of which had a confirmed SQSTM1::NTRK3 gene fusion. Immunohistochemistry for PTEN showed loss of expression in two tumors, one of which had a loss of function PTEN germline alteration. Clinical follow-up was available for 14 patients (range 24-347 months, median 101 months). Four patients had local/regional recurrences, and one patient had distant recurrences (bones and liver). At last, follow-up 10 patients were alive with no evidence of disease, 1 was alive with disease, 1 was alive with an unknown status, 1 died of disease, and 1 died of unknown causes. In summary, we report 15 additional cases of pediatric and young adult high-grade follicular cell-derived non-anaplastic thyroid carcinoma, with a subset harboring DICER1 (n = 5), NTRK (n = 2), and PTEN (n = 2) gene alterations. In this limited case series, two patients were dead at the last follow-up. Whether these findings are consistent within this patient population remains to be addressed as more patient series are published.

Dynamic estimates of survival of patients with poorly differentiated thyroid carcinoma: a population-based study

Background

The real-time prognostic data of patients with poorly differentiated thyroid carcinoma (PDTC) after surviving for several years was unclear. This study aimed to employ a novel method to dynamically estimate survival for PDTC patients.

Methods

A total of 913 patients diagnosed with PDTC between 2014 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database, was recruited in our study. Kaplan-Meier method was used to estimate the overall survival (OS). The conditional survival (CS) outcomes of PDTC were analyzed and CS rates were calculated using the formula CS(y/x) = OS(y+x)/OS(x), whereby CS(y/x) denotes the probability of a patient enduring an additional y years subsequent to surviving x years following the diagnosis of PDTC. The least absolute shrinkage and selection operator (LASSO) regression was employed to identify prognostic predicters and multivariate Cox regression was utilized to develop a CS-nomogram. Finally, the performance of this model was evaluated and validated.

Results

Kaplan-Meier survival analysis unveiled patient outcomes demonstrating an OS rate of 83%, 75%, and 60% respectively at the end of 3, 5, and 10 years. The novel CS analysis highlighted a progressive enhancement in survival over time, with the 10-year cumulative survival rate progressively augmenting from its initiation of 60% to 66%, 69%, 73%, 77%, 81%, 83%, 88%, 93%, and finally 97% (after surviving for 1-9 years, respectively) each year. And then 11 (11/15) predictors including age at diagnosis, sex, histology type, SEER stage, T stage, N stage, M stage, tumor size, coexistence with other malignancy, radiotherapy and marital status, were selected by LASSO analysis under the condition of lambda.min. Multivariate Cox regression analysis further highlighted the significant impact of all these predictors on the OS of PDTC and we successfully established and validated a novel CS-nomogram for real-time and dynamic survival prediction.

Conclusions

This was the first study to analyze the CS pattern and demonstrate a gradual improvement in CS over time in long-term PDTC survivors. We then successfully developed and validated a novel CS-nomogram for individualized, dynamic, and real-time survival forecasting, empowering clinicians to adapt and refine the patient-tailored treatment strategy promptly with consideration of evolving risks.

Cytologic features of differentiated high-grade thyroid carcinoma: A multi-institutional study of 40 cases

BACKGROUND

Differentiated high-grade thyroid carcinoma (DHGTC) is recently recognized by the World Health Organization (WHO) as a subgroup of thyroid carcinomas with high-grade features while retaining the architectural and/or cytologic features of well-differentiated follicular-cell-derived tumors. The cytomorphology of DHGTC is not well documented despite potential implications for patient triage and management.

METHODS

The pathology archives of six institutions were searched for cases diagnosed on resection as "high-grade thyroid carcinoma" using WHO criteria. The fine-needle aspiration (FNA) cohort represents a 10-year period (2013-2023); all were reviewed to confirm DHGTC classification. The corresponding FNAs were assessed for 32 cytomorphologic features.

RESULTS

Forty cases of DHGTC with prior FNA were identified. The mean patient age was 64.2 years. The average lesion size was 4.9 cm, and the majority demonstrated a TI-RADS score of 4 or 5 (95.2%). Three main high-grade subsets of DHGTC based on corresponding histology included papillary thyroid carcinoma (65%), follicular carcinoma (22.5%), and oncocytic carcinoma (12.5%). Over 97% of FNA cases were classified as Bethesda category IV or above. Approximately 25% of DHGTC showed cytologic features that included marked cytologic atypia, increased anisonucleosis, large oval nuclei, mitotic activity, or necrosis (p < .05); 68% of DHGTC cases were associated with high-risk molecular alterations. TERT mutations occurred in 41%, of which 89% of these were associated with a second mutation, usually RAS or BRAF p.V600E.

CONCLUSIONS

Cytology has a low sensitivity for DHGTC, although a subset of DHGTCs have cytologic features raising the possibility of a high-grade thyroid carcinoma. Other findings include high-risk molecular changes and clinicopathologic features such as older patient age and larger lesion size.

Prognosis of Poorly Differentiated Thyroid Carcinoma: A Systematic Review and Meta-Analysis

BACKGRUOUND

Poorly differentiated thyroid carcinoma (PDTC) accounts for a small portion of thyroid carcinomas but contributes to a significant proportion of thyroid carcinoma-associated deaths. The clinicopathological prognostic factors and clinical outcomes of PDTC remain unclear. We aimed to evaluate the clinical outcomes of patients with PDTC after curative treatment.

METHODS

A comprehensive search was performed up to September 2023. We included studies investigating treatment outcomes in patients with PDTC who underwent initial surgery. The 5-year disease-free survival (DFS) and overall survival (OS) were extracted. In this meta-analysis, the enrolled PDTC histological criteria included 3rd, 4th, and 5th World Health Organization (WHO) and Memorial Sloan Kettering Cancer Center (MSKCC) classification. A random-effects model was used for the pooled proportion analysis. Meta-regression analysis was conducted to evaluate the prognostic factors.

RESULTS

Twenty retrospective studies published between 2007 and 2023, including 1,294 patients, met all inclusion criteria. Studies that diagnosed PDTC based on various histological criteria including 3rd WHO (n=5), 4th WHO (n=12), 5th WHO (n=2), and MSKCC (n=1) were included. Overall, 5-year DFS and 5-year OS were 49.4% (95% confidence interval [CI], 42.3 to 56.4) and 73.8% (95% CI, 66.5 to 79.9), with moderate heterogeneity of 58% and 55%, respectively. In meta-regression analysis, extrathyroidal extension (ETE) was a prognostic factor for OS.

CONCLUSION

The meta-analysis of DFS and OS in patients with PDTC show the moderate heterogeneity with a variety of histological criteria. ETE appears to have a significant impact on OS, regardless of histological criteria.

Management of Poorly Differentiated Thyroid Cancer and Differentiated High-Grade Thyroid Carcinoma

Thyroid carcinoma of follicular cell origin exists on a histopathologic and clinical spectrum. The authors focus on the category of tumors that fall between the very favorable well-differentiated thyroid carcinomas and the very unfavorable anaplastic thyroid carcinomas. These intermediately aggressive tumors include poorly differentiated thyroid carcinoma and the newly defined differentiated high-grade thyroid carcinoma. Both diagnoses require certain histopathologic requirements be met in order to accurately identify these tumors post-operatively. Management remains primarily surgical though adjunctive treatments such as molecular targeted therapies (eg, tyrosine kinase inhibitors) and differentiation therapy (to restore tumor response to radioactive iodine) are also becoming available.

The Long Journey towards Personalized Targeted Therapy in Poorly Differentiated Thyroid Carcinoma (PDTC): A Case Report and Systematic Review

BACKGROUND

Poorly differentiated thyroid carcinoma (PDTC) has an intermediate prognosis between indolent well-differentiated thyroid carcinoma (TC) and anaplastic carcinoma. Herein, we present a case report with a PDTC component, along with a systematic review of the literature.

CASE REPORT

We report a case of a 45-year-old man diagnosed with a PDTC component, along with hobnail and tall-cell variant features positive for BRAFV600E mutation, after a total thyroidectomy and neck dissection. Radioactive iodine (RAI)-131 therapy was applied, but an early recurrence led to complementary surgeries. The anti-Tg rise, the presence of new lymph nodes, and the negative whole-bodyradioiodine scan were suggestive of a radioiodine-resistant tumor. Lenvatinib, sorafenib, dabrafenib/trametinib, cabozantinib and radiotherapy were all administered, controlling the tumor for a period of time before the patient ultimately died post-COVID infection. Systematic Review: We searched PubMed, Scopus, and WebofScience to identify studies reporting clinicopathological characteristics, molecular marker expression, and management of non-anaplastic TC with any proportion of PDTC in adult patients. Of the 2007 records retrieved, 82were included in our review (PROSPERO-ID545847).

CONCLUSIONS

Our case, together with the systematic review, imply that a combination of molecular-targetedtreatments may be safe and effective in patients with RAI-resistantBRAF-mutated advanced PDTC when surgery has failed to control tumor progression.

A Comprehensive Review and Insights into the New Entity of Differentiated High-Grade Thyroid Carcinoma

Differentiated high-grade thyroid carcinoma (DHGTC) is a new subset within the spectrum of thyroid malignancies. This review aims to provide a comprehensive overview of DHGTC, focusing on its historical perspective, diagnosis, clinical characteristics, molecular profiles, management, and prognosis. DHGTC demonstrates an intermediate prognosis that falls between well-differentiated thyroid carcinoma and anaplastic thyroid carcinoma. Previously unenumerated, this entity is now recognized for its significant impact. Patients with DHGTC often present at an older age with advanced disease and exhibit aggressive clinical behavior. Molecularly, DHGTC shares similarities with other thyroid malignancies, harboring driver mutations such as BRAFV600E and RAS, along with additional late mutations. The unique behavior and histologic features of DHGTC underscore the necessity of precise classification for prognostication and treatment selection. This highlights the critical importance of accurate diagnosis and recognition by pathologists to enrich future research on this entity further.

Poorly differentiated thyroid carcinoma: molecular, clinico-pathological hallmarks and therapeutic perspectives

Poorly differentiated thyroid carcinoma (PDTC) is a rare and extremely aggressive tumor, accounting for about 2-15% of all thyroid cancer. PDTC has a distinct biological behavior compared to well-differentiated and anaplastic thyroid carcinoma and, in last years, it has been classified as a separate entity from both anatomopathological and clinical points of view. Nevertheless, there is still a lack of consensus among clinicians regarding inclusion criteria and definition of PDTC that affects its diagnosis and clinical management. Due to its rarity and difficulty in classification compared to other tumors, very few studies are available to date and series often include different histotypes in addition to PDTC. This review focuses on main studies concerning PDTC summarizing the evolution in the definition of its diagnosis criteria, clinicopathological features, management, and outcome. The data available confirm that the pathological evaluation and classification of PDTC are crucial and should therefore be standardized. Since the clinical presentation and prognosis of PDTC may vary widely depending on the different stage of the disease at diagnosis, the patient's management may differ in treatment and should be tailored to each patient. Finally, this review discusses advances in molecular insights of PDTC that, together with the implementation of both in vitro and in vivo models, will provide valuable insights into biological mechanisms of progression, metastasis, and invasion of this aggressive thyroid carcinoma. Further studies on larger, carefully selected series are needed to better assess the peculiar features of PDTC and to better define its management by focusing on the best diagnostic and therapeutic approaches.

Poorly differentiated thyroid carcinomas: conceptual controversy and clinical impact

Poorly differentiated thyroid carcinomas (PDTC) are rare diseases; nevertheless, they account for the majority of deaths from non-anaplastic follicular cell-derived thyroid carcinomas. Establishing the diagnosis and treatment of PDTC is challenging given the low incidence and the lack of standardization of diagnostic criteria. These limitations hamper the ability to compare therapeutic modalities and outcomes between recent and older studies. Recently, the 5th edition of the classification of endocrine tumors has been published, which includes changes in nomenclature and the addition of the disease entity of "differentiated high-grade follicular cell-derived carcinomas". On the other hand, the recently witnessed advances in molecular diagnostics have enriched therapeutic options and improved prognosis for patients. We herein review the various historical variations and evolution in the diagnostic criteria for PDTC. This systematic review attempts to clarify the evolution of the histological and molecular characteristics of this disease, its prognosis, as well as its treatment options.

IGF2BPs as novel m6A readers: Diverse roles in regulating cancer cell biological functions, hypoxia adaptation, metabolism, and immunosuppressive tumor microenvironment

m6A methylation is the most frequent modification of mRNA in eukaryotes and plays a crucial role in cancer progression by regulating biological functions. Insulin-like growth factor 2 mRNA-binding proteins (IGF2BP) are newly identified m6A 'readers'. They belong to a family of RNA-binding proteins, which bind to the m6A sites on different RNA sequences and stabilize them to promote cancer progression. In this review, we summarize the mechanisms by which different upstream factors regulate IGF2BP in cancer. The current literature analyzed here reveals that the IGF2BP family proteins promote cancer cell proliferation, survival, and chemoresistance, inhibit apoptosis, and are also associated with cancer glycolysis, angiogenesis, and the immune response in the tumor microenvironment. Therefore, with the discovery of their role as 'readers' of m6A and the characteristic re-expression of IGF2BPs in cancers, it is important to elucidate their mechanism of action in the immunosuppressive tumor microenvironment. We also describe in detail the regulatory and interaction network of the IGF2BP family in downstream target RNAs and discuss their potential clinical applications as diagnostic and prognostic markers, as well as recent advances in IGF2BP biology and associated therapeutic value.

Genomic alterations in thyroid cancer: biological and clinical insights

Tumours can arise from thyroid follicular cells if they acquire driver mutations that constitutively activate the MAPK signalling pathway. In addition, a limited set of additional mutations in key genes drive tumour progression towards more aggressive and less differentiated disease. Unprecedented insights into thyroid tumour biology have come from the breadth of thyroid tumour sequencing data from patients and the wide range of mutation-specific mechanisms identified in experimental models, in combination with the genomic simplicity of thyroid cancers. This knowledge is gradually being translated into refined strategies to stratify, manage and treat patients with thyroid cancer. This Review summarizes the biological underpinnings of the genetic alterations involved in thyroid cancer initiation and progression. We also provide a rationale for and discuss specific examples of how to implement genomic information to inform both recommended and investigational approaches to improve thyroid cancer prognosis, redifferentiation strategies and targeted therapies.

WHO 2022 updates on follicular cell and c-cell derived thyroid neoplasm

The latest edition of the WHO Classification of thyroid tumors was released in 2022 and incorporates novel concepts vital to patient management. Thyroid follicular nodular disease is a term used to collectively represent a wide variety of benign and non-neoplastic lesions, including both clonal and non-clonal proliferations that manifest clinically as multinodular goiter. Thyroid neoplasms develop from follicular cells and can be either benign, low-risk, or malignant. To avoid classifying all lesions under 1 cm in diameter as low-risk illnesses, the new classification method highlights the need for subtyping papillary thyroid cancer based on histomorphologic indicators rather than tumor size. Formerly known as the cribriform-morular variety of papillary thyroid carcinoma, this tumor is now more commonly referred to by its more accurate name, cribriform-morular thyroid carcinoma. Its histogenesis is unknown. Similar to the traditional definition of 'poorly differentiated thyroid carcinoma' according to the Turin criteria, the newly defined 'differentiated high-grade thyroid carcinoma' encompasses papillary thyroid cancer, follicular thyroid carcinomas, and oncocytic carcinomas with high-grade characteristics linked to worse prognosis. The squamous cell subtype of anaplastic thyroid cancer has also recently been characterized as a distinct morphologic pattern. In this article, we will discuss the latest revision to the World Health Organization's classification system for thyroid cancer.

Werner syndrome associated with poorly differentiated thyroid carcinoma and systemic sclerosis-like skin manifestations: A case report

Werner syndrome (WS) is an autosomal recessive disorder characterised by premature ageing. WS patients often experience scleroderma-like manifestation including skin sclerosis and skin ulcer, making it difficult to differentiate WS from systemic sclerosis (SSc). Moreover, there is a high incidence of malignancy and arteriosclerosis-related disease in WS patients. We herein describe a 36-year-old woman with WS who had poorly differentiated thyroid carcinoma, one of the rare phenotypes of thyroid tumour. This case suggested the importance to distinguish WS from SSc and early diagnosis of malignancy.

Characterization of the genomic alterations in poorly differentiated thyroid cancer

Poorly differentiated thyroid carcinoma (PDTC) is a subtype of thyroid cancer that has a high rate of metastasis or recurrence and a relatively poor prognosis. However, there are few studies that have been conducted on PDTC at the whole protein-coding gene scale. Here, we performed genomic profiling of 15 patients with PDTC originated from follicular thyroid carcinoma using whole exome sequencing and also performed gene functional enrichment analysis of differentially expressed genes (DEGs) for three patients. Further, we investigated genetic variants associated with PDTC progression and the characteristics of clinical pathology. We revealed somatic genomic alterations in the RAF1, MAP2K2, and AKT2 genes that were not reported in previous studies. We confirmed frequent occurrences in the RAS gene in patients with PDTC; the genetic alterations were associated with the RAS-RAF-MEK-ERK/JNK, PI3K-AKT-mTOR signaling pathways, and the cell cycle. DEG analysis showed that immune response was lower in cancer tissues than in normal tissues. Through the association analysis of somatic mutations and the characteristics of clinical pathology from patients with PDTC, the somatic mutations of ABCA12, CLIP1, and ATP13A3 were significantly associated with a vascular invasion phenotype. By providing molecular genetic insight on PDTC, this study may contribute to the discovery of novel therapeutic target candidates.

Cytological and Ultrasound Features of Thyroid Nodules Correlate With Histotypes and Variants of Thyroid Carcinoma

CONTEXT

Prognosis is excellent for papillary thyroid carcinoma (PTC), noninvasive follicular thyroid neoplasia with papillary-like nuclear features (NIFT-P), and follicular thyroid carcinoma (FTC) but is poor for poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC). Among PTCs, the prognosis is more favorable for follicular (FV-PTC) and classic (CV-PTC) than for tall cell (TCV-PTC), and solid (SV-PTC) variants.

OBJECTIVE

To associate histotypes and variants of thyroid carcinoma with ultrasound and cytological features.

METHODS

Histology of 1018 benign tumors and 514 PTC (249 CV, 167 FV, 49 TC, 34 SV, and 15 other variants), 52 NIFT-P, 50 FTC, 11 PDTC, and 3 ATC was correlated with fine-needle aspiration biopsy categories (Italian classification: TIR1, TIR2, TIR3A, TIR3B, TIR4, and TIR5) and ultrasound features at the Endocrinology Unit, University Hospital of Pisa. In total, 1117 patients with thyroid nodule(s) who underwent thyroidectomy were included.

RESULTS

Of PTC, 36.3% had indeterminate cytology (TIR3A or TIR3B), 56.6% were suspicious for malignancy or malignant (TIR4 or TIR5); 84.0% FTC and 69.3% NIFT-P were TIR3A or TIR3B; 72.5% FV-PTC and 73.6% SV-PTC were TIR3A or TIR3B; 79.9% CV-PTC and 95.9% TCV-PTC were TIR4 or TIR5. The association of a hypoechoic pattern, irregular margins, and no microcalcifications was more frequent in TCV-PTC than in CV-PTC (P = .02, positive predictive value = 38.9%; negative predictive value = 85.5%).

CONCLUSION

At cytology, most FTC, NIFT-P, FV-PTC, and SV-PTC were indeterminate, most CV-PTC and TCV-PTC were suspicious for malignancy or malignant. Ultrasound can be helpful in ruling out TCV-PTC.

Incidence and Clinicopathological Features of Differentiated High-Grade Thyroid Carcinomas: An Institutional Experience

Differentiated high-grade thyroid carcinoma (DHGTC) is a new entity in the 2022 WHO classification. We aimed to investigate the incidence and clinicopathological features of differentiated HG thyroid carcinoma (DHGTC) and compare the clinicopathological parameters of DHGTC, DTC without HG features, and poorly differentiated thyroid carcinoma (PDTC). A total of 1069 DTCs including papillary thyroid carcinomas (PTCs) and follicular thyroid carcinomas (FTCs) were included in this study. Consecutive 22 PDTCs were also included for comparative purposes. There were a total of 14 (1.3%) cases of DHGTCs, with 13 HGPTCs (1.2% of PTCs) and one HGFTC (6.7% of FTCs). Compared to DTCs without HG features, DHGTCs were associated with larger tumor size, presence of blood vessel invasion, gross extrathyroidal extension, distant metastasis at the time of diagnosis, higher American Joint Committee on Cancer stage, high American Thyroid Association risk, and TERT promoter mutations. DHGTC and PDTC showed a significantly shorter recurrence-free survival (RFS) than DTC without HG features. Multivariate Cox regression analysis revealed that blood vessel invasion, lateral node metastasis, TERT promoter mutations, and HG features were independent prognostic factors (all p < 0.05). When tumor necrosis and increased mitotic count were evaluated separately, tumor necrosis, but not increased mitotic counts, was found to be an independent prognostic factor (p = 0.006). This study confirmed that DHGTC is significantly associated with aggressive clinicopathological features and poor clinical outcomes, similar to PDTC. Although the incidence is low, careful microscopic examination of HG features in DTC is required.

Pathogenesis of cancers derived from thyroid follicular cells

The genomic simplicity of differentiated cancers derived from thyroid follicular cells offers unique insights into how oncogenic drivers impact tumour phenotype. Essentially, the main oncoproteins in thyroid cancer activate nodes in the receptor tyrosine kinase-RAS-BRAF pathway, which constitutively induces MAPK signalling to varying degrees consistent with their specific biochemical mechanisms of action. The magnitude of the flux through the MAPK signalling pathway determines key elements of thyroid cancer biology, including differentiation state, invasive properties and the cellular composition of the tumour microenvironment. Progression of disease results from genomic lesions that drive immortalization, disrupt chromatin accessibility and cause cell cycle checkpoint dysfunction, in conjunction with a tumour microenvironment characterized by progressive immunosuppression. This Review charts the genomic trajectories of these common endocrine tumours, while connecting them to the biological states that they confer.

Newly proposed survival staging system for poorly differentiated thyroid cancer: a SEER-based study

OBJECTIVE

Despite the recent release of the 8th edition TNM staging system, the risk stratification for poorly differentiated thyroid cancer (PDTC) remains controversial.

STUDY DESIGN

Retrospective study.

SETTING

SEER database and the First Hospital of China Medical University (FHCMU) database.

METHODS

Between 2004 and 2015, 1201 PDTC patients from the SEER database were enrolled to propose a new staging system. 38 PDTC patients were included from the FHCMU.

RESULTS

A retrospective analysis of 1201 PDTC cases was performed, and a new staging classification was developed as follows: stage I: age < 55 and T1/any N/M0 (n = 127, 10.57%); stage II: age < 55 and T2-4/any N/M0 or age ≥ 55 and T1-2/any N/M0 (n = 523, 43.55%); stage III: age < 55 and any T/N0/M1 or age ≥ 55 and any T3/any N/M0 (n = 239, 19.90%); stage IV: age < 55 and any T/N1/M1 or age ≥ 55 and T4/any N/M0, and T/any N/M1 (n = 312, 25.98%). The 10-year disease-specific survival rates of patients in the new stages I, II, III, and IV were 97.9%, 77.9%, 35.3%, and 12.1%, respectively. The proportion of variation explained (PVE) for disease-specific survival of the proposed system was higher than that of the 8th AJCC TNM staging (30.61% vs. 27.15%). The accuracy of the staging system was verified in 38 PDTC patients from the FHCMU.

CONCLUSION

The proposed staging system provided a more accurate risk stratification for PDTC patients. The new staging model may facilitate the design of personalized treatment strategies for PDTC patients.

No Longer Well-Differentiated: Diagnostic Criteria and Clinical Importance of Poorly Differentiated/High-Grade Thyroid Carcinoma

Poorly differentiated thyroid carcinoma (PDTC) and differentiated high-grade thyroid carcinoma (DHGTC) are uncommon thyroid malignancies, recently (re)codified into distinct entities with overlapping clinical significance. Recognizing them may be challenging for the general practitioner and subspecialty pathologist alike. This article will describe the required features to diagnose PDTC and DHGTC, differential diagnostic considerations, molecular findings, and clinical implications. It is intended to be a general synopsis of the most critical elements of PDTC and DHGTC as well as a summary of points in approaching these challenging cases.

High-Grade Non-Anaplastic Thyroid Carcinomas of Follicular Cell Origin: A Review of Poorly Differentiated and High-Grade Differentiated Carcinomas

Poorly differentiated thyroid carcinoma (PDTC) and high-grade differentiated thyroid carcinoma (HGDTC) are considered high-grade follicular-derived thyroid carcinomas, with prognoses intermediate between well-differentiated and anaplastic thyroid carcinoma. Both share the presence of invasion, thyroid follicular-cell origin, and tumor necrosis or increased mitoses (≥ 3 mitoses per 2 mm² in PDTC and ≥ 5 mitoses per 2 mm² in HGDTC), without anaplastic dedifferentiation. PDTC must possess solid, trabecular, or insular growth and lack classic papillary-like nuclei; HGDTC can be of any architectural or nuclear morphology (follicular-like, papillary-like, oncocytic). Transformation may be accompanied by acquisition of high-risk mutations (such as TP53 or TERT promoter) on top of RAS-like or BRAF p.V600E-like (including NTRK-fusion) initial driver mutations. These carcinomas most frequently affect adults and often present with metastases (20-50%) or wide local invasion. As PDTC and HGDTC may be radioactive iodine resistant, post-surgical therapy may consist of external beam radiotherapy or targeted, mutation-dependent chemotherapy, such as tyrosine kinase inhibitors. Ten-year disease specific survival is as low as 50%. Awareness of high-grade features in the diagnostic setting is important for patient prognosis and triage of tissue for molecular analysis in order to guide relevant clinical management and therapy.

Significance of oncocytic features in poorly differentiated thyroid carcinoma - a bi-institutional experience

Poorly differentiated thyroid carcinoma (PDTC), defined by Turin criteria, comprises a subset of high-grade follicular-derived thyroid carcinomas with intermediate prognosis. While differentiated oncocytic thyroid carcinomas demonstrate clinicopathologic and genetic differences compared to their non-oncocytic counterparts, similar data is limited in oncocytic (Hurthle) PDTCs (OPDTCs). Here, we assessed the impact of various oncocytic cut-offs in PDTCs on clinical, histologic and survival parameters.Our bi-institutional cohort comprised 210 primary PDTCs with available slides reviewed by at least one pathologist. Histologic features, including oncocytic fraction, were recorded. Clinicopathologic data were obtained, including overall survival (OS), disease-free survival (DFS), disease-specific survival (DSS), locoregional recurrence free survival (LRRFS), and distant metastasis-free survival (DMFS). Radioactive iodine avidity data was available for 125 PDTCs based on postoperative whole-body scanning.Within our cohort, 39.0% PDTCs had any oncocytic component with 24.8% meeting the 75% World Health Organization (WHO) oncocytic definition. Any oncocytic component and > 25% oncocytic cut-off correlated with decreased DSS and LRRFS, respectively, compared to non-oncocytic PDTCs (NOPDTCs) on univariate and multivariate analysis. The 100% oncocytic cut-off was significant for DSS on univariate analysis but a non-significant trend on multivariate analysis. Any oncocytic cut-off (100%, > 75%, > 50%, > 25%, or > 0%) conferred higher radioactive iodine (RAI)-refractoriness to OPDTCs compared to NOPDTCs. NF1 and PTEN alterations were enriched in OPDTCs (40% vs. 0%, and 60% vs 8%, respectively), whereas NRAS mutations were frequent in NOPDTCs (47% vs. 7%).Among PDTCs, the presence of oncocytes led to downward trend in all outcome parameters, especially for DSS and LRRFS. OPDTCs were enriched in NF1 and PTEN mutations. Consistently, all oncocytic cut-offs were associated with RAI-refractoriness. Accordingly, additional studies are needed to reassess the current 75% cut-off used to define oncocytic thyroid lesions.

Aggressive variants of follicular cell-derived thyroid carcinoma: an overview

PURPOSE

The incidence of thyroid carcinoma has increased globally in the past years. Papillary thyroid carcinoma (PTC) is the most frequent neoplasm of the thyroid gland comprehending the 90% of the thyroid carcinoma and has an indolent clinical behaviour. However, some variants of follicular cell-derived thyroid carcinoma, including variants of classic of PTC, have been identified that show a more aggressive biological behaviour. An accurate diagnosis of these entities is crucial for planning a more aggressive treatment and improving patients' prognosis of patients. The aim of this review is to present the main clinical, histological, and molecular features of aggressive variants of follicular cell-derived thyroid carcinoma, and to provide useful histological parameters for determining the most suitable therapeutic strategy for patients affected by these forms.

RESULTS

Variants of classic PTC such as the diffuse sclerosing variant (DSV), the tall cell variant (TCV), the columnar cell variant (CCV), the solid/trabecular variant (STV) and the hobnail variant (HV), and other variants of follicular cell-derived thyroid carcinoma, such as poorly differentiated thyroid carcinoma (PDTC), and anaplastic thyroid carcinoma (ATC), are associated with aggressive behaviour.

CONCLUSIONS

The correct identification and diagnosis of aggressive variants of follicular cell-derived thyroid carcinoma is important, as they allow the clinician to adopt the most refined therapeutic strategies in order to the survival of the patients.

Management of thyroid nodules

In the past 30 years, there has been a substantial rise in the detection of thyroid nodules. Largely asymptomatic, thyroid nodules are most often incidental findings that typically pose minimal risk. Data supporting these findings show a rapid rise in the incidental detection of thyroid nodules and cancer, but minimal effect on mortality rates, despite treatment. These data imply that historical approaches to thyroid nodule and cancer care might at times include unnecessary or excessive care. To address this issue, the past decade has witnessed an increasingly conservative approach to nodule management, seeking to individualise care and provide the most focused intervention that leads to favourable outcomes. Benign nodules can be safely monitored with minimal, or long-interval follow-up imaging. Molecular testing should be considered for cytologically indeterminate nodules because of its ability to improve preoperative cancer risk determination and reduce unnecessary surgery. The treatment of biopsy-proven malignant nodules has become increasingly nuanced, since recommendations for near-total thyroidectomy are no longer routine. Hemithyroidectomy is now commonly considered when operative intervention is favoured. Some patients with small volume, isolated cancerous nodules are safely managed non-operatively with active monitoring. In summary, modern management strategies for thyroid nodular disease seek to incorporate the growing amount of available diagnostic and prognostic data, inclusive of demographic, radiological, pathological and molecular findings. Once obtained, an individualised management plan can be effectively formulated.

Peptide receptor radionuclide therapy (PRRT) in radioiodine-refractory thyroid cancer: A case report of significant response to lu177 DOTA-TATE treatment

A 59-year-old woman with follicular thyroid carcinoma underwent total thyroidectomy followed by radioiodine treatment. Following treatment, the whole-body scan did not show any abnormal radioiodine uptake. However, during the follow-up, the serum thyroglobulin (Tg) value increased without detectable thyroglobulin-antibodies. We performed a Ga-68 DOTA-TATE PET/CT showing a sternal lesion and several lung nodules with high somatostatin receptor density. Also, on the next day, FDG PET/CT was performed, which confirmed the findings. Considering the high levels of somatostatin receptor expression in such metastases, we planned lu177 DOTA-TATE therapy. After two cycles of lu177 DOTA-TATE injection, serum thyroglobulin significantly dropped, and she claimed that her sternal pain and dyspnea were much better. This was the case of a patient suffering from iodine-refractory follicular thyroid carcinoma, with somatostatin-receptor expression, treated with 177Lu-DOTA-TATE, showing a significant response.

Poorly differentiated thyroid carcinoma: a clinician's perspective

Poorly differentiated thyroid carcinoma (PDTC) is a rare thyroid carcinoma originating from follicular epithelial cells. No explicit consensus can be achieved to date due to sparse clinical data, potentially compromising the outcomes of patients. In this comprehensive review from a clinician's perspective, the epidemiology and prognosis are described, diagnosis based on manifestations, pathology, and medical imaging are discussed, and both traditional and emerging therapeutics are addressed as well. Turin consensus remains the mainstay diagnostic criteria for PDTC, and individualized assessments are decisive for treatment option. The prognosis is optimal if complete resection is performed at early stage but dismal in nearly half of patients with locally advanced and/or distant metastatic diseases, in which adjuvant therapies such as 131I therapy, external beam radiation therapy, and chemotherapy should be incorporated. Emerging therapeutics including molecular targeted therapy, differentiation therapy, and immunotherapy deserve further investigations to improve the prognosis of PDTC patients with advanced disease.

Overview of the 2022 WHO Classification of Thyroid Neoplasms

This review summarizes the changes in the 5th edition of the WHO Classification of Endocrine and Neuroendocrine Tumors that relate to the thyroid gland. The new classification has divided thyroid tumors into several new categories that allow for a clearer understanding of the cell of origin, pathologic features (cytopathology and histopathology), molecular classification, and biological behavior. Follicular cell-derived tumors constitute the majority of thyroid neoplasms. In this new classification, they are divided into benign, low-risk, and malignant neoplasms. Benign tumors include not only follicular adenoma but also variants of adenoma that are of diagnostic and clinical significance, including the ones with papillary architecture, which are often hyperfunctional and oncocytic adenomas. For the first time, there is a detailed account of the multifocal hyperplastic/neoplastic lesions that commonly occur in the clinical setting of multinodular goiter; the term thyroid follicular nodular disease (FND) achieved consensus as the best to describe this enigmatic entity. Low-risk follicular cell-derived neoplasms include non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), thyroid tumors of uncertain malignant potential, and hyalinizing trabecular tumor. Malignant follicular cell-derived neoplasms are stratified based on molecular profiles and aggressiveness. Papillary thyroid carcinomas (PTCs), with many morphological subtypes, represent the BRAF-like malignancies, whereas invasive encapsulated follicular variant PTC and follicular thyroid carcinoma represent the RAS-like malignancies. This new classification requires detailed subtyping of papillary microcarcinomas similar to their counterparts that exceed 1.0 cm and recommends not designating them as a subtype of PTC. The criteria of the tall cell subtype of PTC have been revisited. Cribriform-morular thyroid carcinoma is no longer classified as a subtype of PTC. The term "Hürthle cell" is discouraged, since it is a misnomer. Oncocytic carcinoma is discussed as a distinct entity with the clear recognition that it refers to oncocytic follicular cell-derived neoplasms (composed of > 75% oncocytic cells) that lack characteristic nuclear features of PTC (those would be oncocytic PTCs) and high-grade features (necrosis and ≥ 5 mitoses per 2 mm²). High-grade follicular cell-derived malignancies now include both the traditional poorly differentiated carcinoma as well as high-grade differentiated thyroid carcinomas, since both are characterized by increased mitotic activity and tumor necrosis without anaplastic histology and clinically behave in a similar manner. Anaplastic thyroid carcinoma remains the most undifferentiated form; squamous cell carcinoma of the thyroid is now considered as a subtype of anaplastic carcinoma. Medullary thyroid carcinomas derived from thyroid C cells retain their distinct section, and there is a separate section for mixed tumors composed of both C cells and any follicular cell-derived malignancy. A grading system for medullary thyroid carcinomas is also introduced based on mitotic count, tumor necrosis, and Ki67 labeling index. A number of unusual neoplasms that occur in the thyroid have been placed into new sections based on their cytogenesis. Mucoepidermoid carcinoma and secretory carcinoma of the salivary gland type are now included in one section classified as "salivary gland-type carcinomas of the thyroid." Thymomas, thymic carcinomas and spindle epithelial tumor with thymus-like elements are classified as "thymic tumors within the thyroid." There remain several tumors whose cell lineage is unclear, and they are listed as such; these include sclerosing mucoepidermoid carcinoma with eosinophilia and cribriform-morular thyroid carcinoma. Another important addition is thyroblastoma, an unusual embryonal tumor associated with DICER1 mutations. As in all the WHO books in the 5th edition, mesenchymal and stromal tumors, hematolymphoid neoplasms, germ cell tumors, and metastatic malignancies are discussed separately. The current classification also emphasizes the value of biomarkers that may aid diagnosis and provide prognostic information.

DICER1 tumor predisposition syndrome: an evolving story initiated with the pleuropulmonary blastoma

DICER1 syndrome (OMIM 606241, 601200) is a rare autosomal dominant familial tumor predisposition disorder with a heterozygous DICER1 germline mutation. The most common tumor seen clinically is the pleuropulmonary blastoma (PPB), a lung neoplasm of early childhood which is classified on its morphologic features into four types (IR, I, II and III) with tumor progression over time within the first 4-5 years of life from the prognostically favorable cystic type I to the unfavorable solid type III. Following the initial report of PPB, its association with other cystic neoplasms was demonstrated in family studies. The detection of the germline mutation in DICER1 provided the opportunity to identify and continue to recognize a number seemingly unrelated extrapulmonary neoplasms: Sertoli-Leydig cell tumor, gynandroblastoma, embryonal rhabdomyosarcomas of the cervix and other sites, multinodular goiter, differentiated and poorly differentiated thyroid carcinoma, cervical-thyroid teratoma, cystic nephroma-anaplastic sarcoma of kidney, nasal chondromesenchymal hamartoma, intestinal juvenile-like hamartomatous polyp, ciliary body medulloepithelioma, pituitary blastoma, pineoblastoma, primary central nervous system sarcoma, embryonal tumor with multilayered rosettes-like cerebellar tumor, PPB-like peritoneal sarcoma, DICER1-associated presacral malignant teratoid neoplasm and other non-neoplastic associations. Each of these neoplasms is characterized by a second somatic mutation in DICER1. In this review, we have summarized the salient clinicopathologic aspects of these tumors whose histopathologic features have several overlapping morphologic attributes particularly the primitive mesenchyme often with rhabdomyoblastic and chondroid differentiation and an uncommitted spindle cell pattern. Several of these tumors have an initial cystic stage from which there is progression to a high grade, complex patterned neoplasm. These pathologic findings in the appropriate clinical setting should serve to alert the pathologist to the possibility of a DICER1-associated neoplasm and initiate appropriate testing on the neoplasm and to alert the clinician about the concern for a DICER1 mutation.

Development and validation of a nomogram model for cancer-specific survival of patients with poorly differentiated thyroid carcinoma: A SEER database analysis

BACKGROUND

This study aimed to establish and validate an accurate prognostic model, based on demographic and clinical parameters, for predicting the cancer-specific survival (CSS) of patients with poorly differentiated thyroid carcinoma (PDTC).

MATERIALS AND METHODS

Patients diagnosed with PDTC between 2004 to 2015 were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Randomly split the data into training and validation sets. Kaplan-Meier analysis with the log-rank test was performed to compare the survival distribution among cases. Univariate and multivariate Cox proportional hazards regression analyses were used to identify independent prognostic factors, which were subsequently utilized to construct a nomogram for predicting the 5- and 10-year cancer-specific survival of patients with PDTC. The discriminative ability and calibration of the nomogram model were assessed using the concordance index and calibration plots, respectively. In addition, we performed a decision curve analysis to assess the clinical value of the nomogram. Simultaneously, we compared the predictive performance of the nomogram model against that of the American Joint Committee on Cancer (AJCC) T-, N-, M-stage.

RESULTS

A total of 970 eligible patients were randomly assigned to either a training cohort (n = 679) or a validation cohort (n = 291). The Kaplan-Meier analysis revealed that there were no significant differences in cumulative survival based on the race, radiation, and marital status of patients. The stepwise Cox regression model showed that the model was optimal when the following five variables were included: age, tumor size, T-, N-, and M-stage. A nomogram was developed as a graphical representation of the model and exhibited good calibration and discriminative ability in the study. Compared to the T-, N-, and M-stage, the C-index of nomogram (training group: 0.807, validation group: 0.802), the areas under the receiver operating characteristic curve of the training set (5-year AUC: 0.843, 10-year AUC:0.834) and the validation set (5-year AUC:0.878, 10-year AUC:0.811), and the calibration plots of this model all exhibited better performance. At last, compared with T-, N-, and M-stage, the decision curve analysis indicated that the nomogram had excellent clinical net benefit.

CONCLUSIONS

The nomogram developed by us can accurately predict the CSS of PDTC patients. It can help clinicians determine appropriate treatment strategies for poorly differentiated thyroid carcinoma patients.

Prostate-Specific Membrane Antigen in Anaplastic and Poorly Differentiated Thyroid Cancer-A New Diagnostic and Therapeutic Target?

Several studies have demonstrated an expression of the prostate-specific membrane antigen (PSMA) in the cancer-related neovasculature of thyroid malignancies. Due to the poor prognosis and limited therapeutic options for patients with anaplastic (ATC) and poorly differentiated (PDTC) thyroid carcinoma, the aim of our study was to investigate the theranostic approach of PSMA expression in these patients. The PSMA uptake on Gallium-68 (68Ga)-PSMA-positron emission tomography/computed tomography (PET/CT) and glucose uptake on F-18-Fluordeoxyglucose (18F-FDG)-PET/CTs were analysed in two ATC and six PDTC patients. The PSMA expression in corresponding patients' tissue samples was detected by immunohistochemistry. In addition, various tissue sections from 22 ATC and six PDTC patients were examined concerning PSMA expression. 68Ga-PSMA-PET/CT showed heterogeneous PSMA expression among patients and lesions. Six of the eight analyzed patients (two ATC, four PDTC) showed increased glucose metabolism without increased PSMA uptake after PET/CT. In one patient (PDTC), 18F-FDG-PET/CT tracer uptake was positive and 68Ga-PSMA-PET/CT showed heterogeneous results. Another patient (PDTC) evidenced only PSMA-positive lesions and received two cycles of Lutetium-177 (177Lu)-PSMA therapy, which kept his disease stable for seven months. There was a correlation between immunohistochemical PSMA expression and uptake on 68Ga-PMSA-PET/CT in three of the examined patients. Twenty-seven of the analyzed 39 ATC and 13 of the analyzed 22 PDTC tissue sections showed a strong PSMA expression. Considering the rarity of PDTC and ATC, which is the reason for the small patient population we studied, the findings of this study confirm the high diagnostic sensitivity and superiority of 18F-FDG-PET/CT in comparison to 68Ga-PSMA-PET/CT in the diagnosis of ATC and PDTC. However, it can be suggested that 68Ga-PMSA-PET/CT can be considered as a beneficial adjunct to the well-established 18F-FDG-PET/CT for a few individual selected patients with ATC and PDTC to detect lesions not discovered by 18F-FDG-PET/CT and to determine patients' eligibility for a radioligand therapy. Radiolabelled PSMA-ligands may, in the future, represent a theranostic approach with only minor side effects for a few individual selected patients with ATC and PDTC who need alternative treatment options in case of progression when established therapies are no longer effective. However, due to the small sample size of our collective, larger studies are needed to allow for a final evaluation on the significance of PSMA-targeted diagnostic and therapy for ATC and PDTC.

Poorly Differentiated Thyroid Carcinoma: Single Centre Experience and Review of the Literature

There is controversy in the literature regarding a distinct subset of thyroid carcinoma whose histologically classification falls between well-differentiated and anaplastic carcinomas, previously identified as 'poorly differentiated thyroid carcinoma' (PDTC), or 'insular carcinoma', in view of the peculiar morphological characteristics of the cell groupings. The correct diagnosis and treatment of this entity have important prognostic and therapeutic significance. In this review, we describe the epidemiology, diagnosis, and management of PDTC and report our single centre experience to add to the limited evidence existing in the literature.

Immunohistochemical Study of IMP3 Expression in Laryngeal Squamous Cell Carcinoma

BACKGROUND: IMP3 is an RNA binding protein, which is strongly expressed in malignant tumors, promoting tumor cell proliferation. AIM: The aim of the study was to evaluate the expression of IMP3 in laryngeal squamous cell carcinoma (SCC) and to correlate the expression of IMP3 with available clinicopathological data. METHODS: Sixty one total laryngectomy and laryngoscopic biopsies; collected from the Pathology Department, Faculty of Medicine, Cairo University. Two slides were prepared from each paraffin embedded tumor block, one slide for Hematoxylin and Eosin staining, and the other for immunohistochemical staining by IMP3 polyclonal antibody. RESULTS: Thirty-seven cases (60.7%) showed positive IMP3 expression, and a statistically significant correlation was found between IMP3 expressions in normal, dysplastic epithelium/in situ component, and the invasive malignant tumor tissue. Correlations between IMP3 expression and other available clinicopathological data were all non-significant. CONCLUSION: This study suggests that IMP3 might play a role in laryngeal SCC carcinogenesis and progression process from normal to dysplastic to malignant epithelium, and thus IMP3 might be targeted by gene therapy.

The biological function of IGF2BPs and their role in tumorigenesis

The insulin-like growth factor-2 mRNA-binding proteins (IGF2BPs) pertain to a highly conservative RNA-binding family that works as a post-transcriptional fine-tuner for target transcripts. Emerging evidence suggests that IGF2BPs regulate RNA processing and metabolism, including stability, translation, and localization, and are involved in various cellular functions and pathophysiologies. In this review, we summarize the roles and molecular mechanisms of IGF2BPs in cancer development and progression. We mainly discuss the functional relevance of IGF2BPs in embryo development, neurogenesis, metabolism, RNA processing, and tumorigenesis. Understanding IGF2BPs role in tumor progression will provide new insight into cancer pathophysiology.

Neoadjuvant lenvatinib for inoperable thyroid cancer: A case report and literature review

Background

Poorly differentiated thyroid cancer (PDTC) is now classified as a separate thyroid tumor entity. It has male predominance and poor prognosis compared to differentiated TC.

Case

We report a case of a patient with PDTC who was previously deemed inoperable. A trial of neoadjuvant lenvatinib therapy was given to the patient after that the tumor become operable and the surgery went successfully.

Conclusions

Lenvatinib is a feasible option in patients with inoperable TC and can stabilize the lesion size or even reduce it, leading to a more favorable surgical outcome.

Papillary Thyroid Carcinoma with High-Grade Features Versus Poorly Differentiated Thyroid Carcinoma: An Analysis of Clinicopathologic and Molecular Features and Outcome

Background: Similar to poorly differentiated thyroid carcinoma (PDTC), papillary thyroid carcinoma with high-grade features (PTC HGF) demonstrates increased mitotic activity and/or necrosis; however, PTC HGF is excluded from the World Health Organization (WHO) definition of PDTC based on maintained nuclear features of PTC. Methods: Consecutive tumors that met criteria for PTC HGF, defined as tumors with maintained nuclear features of PTC and mitoses numbering 5 or more per 10 contiguous high-power fields and/or tumor necrosis, and PDTC (defined as per the WHO criteria) were identified. Clinicopathologic characteristics, follow-up data, and targeted next-generation sequencing results were compared between groups. Results: There were 15 PTC HGF and 47 PDTC. PTC HGF was associated with a higher rate of pT4 disease (53% vs. 13%, p = 0.0027) and lymph node metastases (73% vs. 38%, p = 0.049). The disease-specific survival was worse for patients with PTC HGF compared with those with PDTC using Kaplan-Meier estimation (p < 0.001) and was worse in subgroup analysis evaluating patients with widely invasive PDTC (i.e., those with a similar rate of pT4 disease) and PTC HGF (p = 0.040). PTC HGF had a higher BRAF^V600E mutation rate (42% vs. 3%; p = 0.003), a trend toward more gene fusions (25% vs. 3%; p = 0.052), and a higher rate of relative gain of 1q (67% vs. 15%; p = 0.002) than PDTC. Conclusions: Our results demonstrate that PTC HGF are important to recognize based on their aggressive behavior. The molecular differences between PTC HGF and PDTC suggest that PTC HGF should be considered a distinct group from PDTC.

Thyroid Carcinoma: Phenotypic Features, Underlying Biology and Potential Relevance for Targeting Therapy

Thyroid carcinoma consists a group of phenotypically heterogeneous cancers. Recent advances in biological technologies have been advancing the delineation of genetic, epigenetic, and non-genetic factors that contribute to the heterogeneities of these cancers. In this review article, we discuss new findings that are greatly improving the understanding of thyroid cancer biology and facilitating the identification of novel targets for therapeutic intervention. We review the phenotypic features of different subtypes of thyroid cancers and their underlying biology. We discuss recent discoveries in thyroid cancer heterogeneities and the critical mechanisms contributing to the heterogeneity with emphases on genetic and epigenetic factors, cancer stemness traits, and tumor microenvironments. We also discuss the potential relevance of the intratumor heterogeneity in understanding therapeutic resistance and how new findings in tumor biology can facilitate designing novel targeting therapies for thyroid cancer.

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.

Clinicopathological Characteristics and Prognosis of Poorly Differentiated Thyroid Carcinoma Diagnosed According to the Turin Criteria

OBJECTIVE

Poorly differentiated thyroid carcinoma (PDTC) is the primary cause of death in patients with nonanaplastic follicular cell-derived thyroid carcinoma. We purposed to identify the clinical and pathological characteristics of PDTC and their relationship with prognosis.

METHODS

A retrospective analysis was conducted on patients diagnosed with PDTC at our institution from 2010 to 2018. All of their histopathology slides were reviewed by 2 experienced pathologists based on the Turin criteria. Furthermore, information regarding clinical characteristics, pathological characteristics, treatment strategy, and follow-up events were collected. The Kaplan-Meier method was used for survival analysis, while the log-rank test was used to compare survival curves. Then, the Cox proportional hazards model was used to perform univariate and multivariate analyses.

RESULTS

Twenty-six patients with PDTC who met the Turin criteria were enrolled in this study. The median follow-up period of the included 26 patients was 76 months, while the 3- and 5-year survival rates were 40% and 18%, respectively. Notably, univariate analysis revealed that tumor size >4 cm (P = .038), extrathyroidal extension (ETE) (P = .020), distant metastases (P = .047), poorly differentiated areas >60% (P = .049), and Ki-67 labeling index >30% (P = .040) were associated with poor prognosis. On the other hand, multivariate analysis identified ETE (P = .007) and distant metastases (P = .031) as independent risk factors for poor prognosis.

CONCLUSION

PDTC is a rare carcinoma with high invasiveness and poor prognosis. Patients with ETE or distant metastases may have adverse outcomes.

Updates in the Pathologic Classification of Thyroid Neoplasms: A Review of the World Health Organization Classification

Advances in medical sciences and evidence-based medicine have led to momentous changes in classification and management of thyroid neoplasms. Much progress has been made toward avoiding overdiagnosis and overtreatment of thyroid cancers. The new 2017 World Health Organization (WHO) classification of thyroid neoplasms updated the diagnostic criteria and molecular and genetic characteristics reflecting the biology and behavior of the tumors, and newly introduced the category of borderline malignancy or uncertain malignant potential. Some neoplasms were subclassified, renamed, or redefined as a specific entity. This review introduces changes in the fourth edition WHO classification of thyroid tumors and updates the contemporary diagnosis and classification of thyroid tumors. We also discuss several challenges with the proposal of new diagnostic entities, since they have unique histopathologic and molecular features and clinical relevance.

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.

Poorly differentiated thyroid carcinoma : An underdiagnosed entity

Poorly differentiated thyroid carcinomas (PDTCs) are a rare subtype of thyroid carcinomas that are biologically situated between well-differentiated papillary/follicular thyroid carcinomas and anaplastic thyroid carcinomas (ATCs).

The diagnosis of conventional as well as oncocytic poorly differentiated thyroid carcinoma is difficult and often missed in daily routine. The current WHO criteria to allow the diagnosis of PDTCs are based on the results of a consensus meeting held in Turin in 2006. Even a minor poorly differentiated component of only 10%of a given carcinoma significantly affects patient prognosis and the oncocytic subtype may even have a worse outcome. Immunohistochemistry is not much help and is mostly used to exclude a medullary thyroid carcinoma with calcitonin and to establish a follicular cell of origin via thyroglobulin staining.

Due to the concept of stepwise dedifferentiation, there is a vast overlap of different molecular alterations like BRAF, RAS, CTNNB1, TP53 and others between different thyroid carcinoma subtypes. A distinctive molecular tumor profile is therefore currently not available.

PDTCs have a unique miRNA signature, which separates them from other thyroid carcinomas. The average relapse free survival is less than one year and about 50% of patients die of the disease. Modern tyrosine kinase inhibitors offer in conjunction with powerful molecular diagnostic new chances in these difficult to treat carcinomas.

Poorly differentiated thyroid carcinoma of childhood and adolescence: a distinct entity characterized by DICER1 mutations

Poorly differentiated thyroid carcinomas (PDTC) in young individuals are rare and their clinical and histopathologic features, genetic mechanisms, and outcomes remain largely unknown. Here, we report a detailed characterization of a series of six PDTC in patients ≤21 years old defined by Turin diagnostic criteria studied for mutations and gene fusions characteristic of thyroid cancer using targeted next-generation sequencing (NGS) and whole-exome sequencing (WES). All tumors had solid, insular, or trabecular growth pattern and high mitotic rate, and five out of six tumors showed tumor necrosis. Targeted NGS assay identified somatic mutations in the DICER1 gene in five of six (83%) tumors, all of which were "hotspot" mutations encoding the metal-ion binding sites of the RNase IIIb domain of DICER1. WES was performed in five cases which confirmed all hotspot mutations and detected two tumors with additional inactivating DICER1 alterations. Of these two, one was a germline pathogenic DICER1 variant and the other had loss of heterozygosity for DICER1. No other mutations or gene fusions characteristic of adult well-differentiated thyroid cancer and PDTC (BRAF, RAS, TERT, RET/PTC, and other) were detected. On follow-up, available for five patients, three patients died of disease 8-24 months after diagnosis, whereas two were alive with no disease. The results of our study demonstrate that childhood- and adolescent-onset PDTC are genetically distinct from adult-onset PDTC in that they are strongly associated with DICER1 mutations and may herald DICER1 syndrome in a minority. As such, all young persons with PDTC may benefit from genetic counseling. Furthermore, their clinically aggressive behavior contrasts sharply with the indolent nature of the great majority of thyroid tumors with DICER1 mutations reported to date.

Anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) is a rare but significant malignancy due to its high mortality rate. Rendering an accurate diagnosis is crucial given the prognostic implications and treatment ramifications. Based on the prognostic significance of the extent of invasion of the primary tumor, T staging for ATC changed in the most recent edition of the American Joint Committee on Cancer (AJCC) staging manual. In the past 5 years there has been a rapid increase in our understanding of the molecular basis of ATC which has provided the basis for targeted therapy for some ATC patients. In this review, ATC prognostic factors, histologic and immunotypic features, staging updates, and molecular alterations, with an emphasis on those that may impact treatment, will be discussed.

Poorly differentiated thyroid carcinoma: An institutional experience

Purpose

The incidence of poorly differentiated thyroid carcinoma (PDTC) is extremely low among thyroid cancers and there is no standardized treatment guideline for it. In this study, we have analyzed PDTC patients and reviewed their clinicopathological features.

Methods

Data of PDTC patients from our institution are collected through the electronic medical database. We analyzed them by several parameters such as basic demographics, presenting symptom, preoperative cytology results, associated pathology, surgical results, surgery type, and distant metastasis.

Results

We collected 23 cases in our institution. Apart from two patients who were transferred to another hospital upon diagnosis, all 21 operated cases are analyzed. The parameters we studied were age, sex, presenting symptoms, distant metastasis and pathological features such as tumor size, associated pathology, predominant pattern and so on. We also provided descriptive analyses according to the type of presentation and treatment; patients with distant metastasis, juvenile cancer, and concurrent hyperthyroidism. Furthermore, we provided different cases in which the initial surgical plans differed.

Conclusion

We present 21 cases of PDTC patients and clarify their clinicopathological features. Despite some limitations, this study may shed light for future research regarding treatment of PDTC patients.

Histopathology and immunohistochemistry as prognostic factors for poorly differentiated thyroid cancer in a series of Polish patients

Background

Poorly differentiated thyroid cancer (PDTC) is a rare but aggressive type of thyroid cancer (TC) and the main cause of death from non-anaplastic follicular cell-derived TC. Although the Turin criteria are well defined, the pathological features that could serve as diagnostic and prognostic factors remain controversial.

Materials and methods

Forty-nine consecutive PDTC cases were identified in a single cancer center between 2000 and 2018. We analyzed the impact of routine histopathological and immunohistochemical features and several parameters that are not routinely included in pathology reports such as the presence of atypical mitoses, the amount of necrosis, or insulin-like growth factor-II mRNA-binding protein 3 immunostaining on the survival of patients with PDTC. Overall survival (OS) and disease-specific survival (DSS) were calculated using the Kaplan-Meier method.

Results

Of the 49 PDTC 34 (69.4%) showed the insular pattern of growth. The median of poorly differentiated area was 95% (range, 1–100), and 30 (61.2%) patients had a predominant (>50%) insular area. The 5-year OS and DSS rates at a median follow-up of 57 months were 60.6% and 64.3%, respectively. Univariate analysis showed that tumor size >4 cm, presence of atypical mitoses, Ki-67 >5%, and thyroglobulin (Tg)-negative immunostaining were associated with a higher risk of PDTC-related death. Atypical mitoses and Tg negativity were independent factors of worse DSS in multivariate analysis. Patients with insular and predominant insular areas showed a 3- and 6-fold higher risk of PDTC death when they displayed atypical mitoses.

Conclusions

In PDTC, the presence of atypical mitoses may be helpful in identifying patients with poorer outcome and worth including in pathology reports, particularly in tumors with a dominant insular pattern of growth. Additionally, the inclusion of Tg immunostaining may be considered in a prognostic context, and not only as a diagnostic feature.

SEOM clinical guideline thyroid cancer (2019)

Thyroid carcinoma is the most frequent endocrine malignancy and accounts for around 3% of global cancer incidence. Different histologies and clinical scenarios make necessary a multidisciplinary approach that includes new diagnostic methods and surgical, radiopharmaceutical and systemic therapies. This guideline updates several aspects of management of thyroid cancer.