Crucial parameters in thyroid carcinoma reporting - challenges, controversies and clinical implications

Cytomorphological changes in thyroid nodules induced by radiofrequency ablation therapy: Emphasis on recurrent papillary thyroid carcinoma

Radiofrequency ablation (RFA) therapy is a minimally invasive treatment option for benign thyroid nodules and metastatic papillary thyroid carcinoma (PTC). This study investigated the cytomorphological changes induced by RFA in thyroid nodules. The study included patients who received RFA for benign thyroid nodules (n = 6) or recurrent PTC (n = 14), in the thyroid bed or lymph nodes following thyroidectomy. Patients underwent fine-needle aspiration (FNA) or core needle biopsy (CNB) to evaluate therapeutic responses. Most benign thyroid nodules showed acellular or hypocellular cellularity and coagulative necrosis. Thermal artifacts, fibrosis, and foreign body reactions were also noted. All cases were successfully treated, showing reduced nodule size with no recurrence during follow-up. In patients with recurrent PTC, post-RFA biopsies diagnosed 12 out of 14 samples as PTC, with most displaying degenerated tumor cells. Cytomorphological changes included acellular necrosis, nuclear pyknosis, or karyorrhexis. The second biopsy group showed lower cellularity, fewer degenerated cells, and fewer viable PTC cells than the first biopsy group. Two patients with persistent viable PTC cells after repeated RFA underwent surgical treatment. FNA and CNB effectively evaluate the response to RFA and detect residual tumors. Acellular specimens, total necrosis, and severely degenerated tumor cells indicate successful RFA, while viable cells with preserved PTC features suggest incomplete treatment.

[Update on papillary thyroid cancer-What is relevant for surgeons?]

Papillary thyroid cancer (PTC) is the most frequent malignant thyroid tumor in Germany. The diagnosis can only be confirmed by histological examination of the suspicious tissue. The clinical signs, sonographic findings, and the results of fine-needle aspiration, possibly supplemented by subsequent molecular genetic analysis, can confirm the suspected diagnosis before surgery. The prognosis is very good if the diagnosis is made early and, depending on the size of the tumor, complete surgical removal is achieved, with a 10-year survival rate of more than 90%; however, histologically PTC has several variants that are associated with either a high or low risk of metastases and recurrence in patients. Therefore, the extent of necessary treatment, in particular surgical interventions for PTC has been discussed for years. This article provides an overview of the current knowledge on the diagnosis, treatment and prognosis of PTC.

Optimizing unsupervised feature engineering and classification pipelines for differentiated thyroid cancer recurrence prediction

BACKGROUND

Differentiated thyroid cancer (DTC) is a common endocrine malignancy with rising incidence and frequent recurrence, despite a generally favorable prognosis. Accurate recurrence prediction is critical for guiding post-treatment strategies. This study aimed to enhance predictive performance by refining feature engineering and evaluating a diverse ensemble of machine learning models using the UCI DTC dataset.

METHODS

Unsupervised data engineering-specifically dimensionality reduction and clustering-was used to improve feature quality. Principal Component Analysis (PCA) and Truncated Singular Value Decomposition (t-SVD) were selected based on superior clustering metrics: adjusted Rand Index (ARI > 0.55) and V-measure (> 0.45). These were integrated into classification pipelines using Logistic Regression (LR), Support Vector Machine (SVM), Random Forest (RF), K-Nearest Neighbors (KNN), Feedforward Neural Network (FNN), and Gradient Boosting (GB). Model performance was evaluated through bootstrapping on an independent test set, stratified 10-fold cross-validation (CV), and subgroup analyses. Metrics included balanced accuracy, F1 score, AUC, sensitivity, specificity, and precision, each reported with 95% confidence intervals (CIs). SHAP analysis supported model interpretability.

RESULTS

The PCA-based LR pipeline achieved the best test set performance: balanced accuracy of 0.95 (95% CI: 0.90-0.99), AUC of 0.99 (95% CI: 0.97-1.00), and sensitivity of 0.94 (95% CI: 0.84-1.00). In stratified CV, it maintained strong results (balanced accuracy: 0.86; AUC: 0.97; sensitivity: 0.80), with consistent performance across clinically relevant subgroups. The t-SVD-based LR pipeline showed comparable performance on both test and CV sets. SVM and FNN pipelines also performed robustly (test AUCs > 0.99; CV AUCs > 0.96). RF and KNN had high specificity but slightly lower sensitivity (test: ~0.87; CV: 0.77-0.80). GB pipelines showed the lowest overall performance (test balanced accuracy: 0.86-0.88; CV: 0.85-0.88).

CONCLUSIONS

Dimensionality reduction via PCA and t-SVD significantly improved model performance, particularly for LR, SVM, FNN, RF and KNN classifiers. The PCA-based LR pipeline showed the best generalizability, supporting its potential integration into clinical decision-support tools for personalized DTC management.

CLINICAL TRIAL NUMBER

Not applicable.

The Current Understanding of the Molecular Pathogenesis of Papillary Thyroid Cancer

The thyroid is a vital endocrine organ that regulates metabolism, heart rate, respiration, digestion, body temperature, brain development, skin and bone maintenance, and reproduction and fertility. Thyroid cancer (TC) is the most common endocrine malignancy, with an estimate of 44,020 new cases in 2025. Incidence has been increasing, most notably at 4-5% per year in young adults. Papillary thyroid cancer (PTC), the most common TC subtype, accounts for approximately 80% of newly diagnosed TC cases. Furthermore, 2290 deaths are expected from the disease in 2025, with survival at over 98% with treatment. However, as PTC occurs most frequently in young women, recurrences are frequent and the 10-year disease-specific survival rate for advanced PTC is less than 50%. This narrative review aims to describe the current understanding of the thyroid gland, the incidence and subtypes of thyroid cancer, and specifically the diagnosis, prognosis, treatment, and recurrence of PTC. This is supplemented by the role of molecular pathways and biomarkers in PTC.

Impact of Therapeutic Radioactive Iodine on the Recurrence of Papillary Thyroid Cancer With Extranodal Extension in Metastatic Lymph Nodes: A Propensity Score-matched Analysis

PURPOSE

Radioactive iodine therapy (RAI) ≥100 mCi (3.7 GBq) is commonly recommended for papillary thyroid cancer (PTC) patients with extranodal extension (ENE). However, no study has evaluated whether RAI ≥100 mCi is effective in reducing the recurrence of PTC with ENE.

METHODS

This retrospective cohort study enrolled 191 PTC patients with ENE who underwent total thyroidectomy and RAI. Recurrence according to RAI activity (<100 vs. ≥100 mCi) was compared before and after propensity score matching (PSM) (1:2) using Kaplan-Meier curves and Cox proportional hazards regression models. Subgroup analyses according to mass size (<4 and ≥4 cm), gender, blood vessel invasion, lymph node (LN) number (≤5 and >5), and stimulated Tg (sTg) level (<10 and ≥10 ng/mL) before and after PSM were performed.

RESULTS

During about 116 months, 5 (12.5%) and 19 (12.6%) before PSM, five (12.5%) and 3 (3.8%) after PSM recorded recurrence in <100 and ≥100 mCi groups, respectively. The impact of RAI ≥100 mCi on reducing recurrence was not significant before [log-rank P = 0.915, adjusted hazard ratio (HR) 0.49 (0.12-1.85); P = 0.294) and after PSM (log-rank P = 0.077). Subgroup analysis after PSM demonstrated the impact of RAI ≥100 mCi on lowering recurrence only in ENE patients with mass size ≥4 cm (log-rank P = 0.008), LN >5 (log-rank P = 0.007), and sTg ≥10 ng/mL (log-rank P = 0.039).

CONCLUSIONS

In PTC patients with ENE, mass size ≥4 cm, LN >5, or sTg ≥10 ng/mL had a benefit from RAI ≥100 mCi compared with RAI <100 mCi.

Towards a consensus atlas of human and mouse adipose tissue at single-cell resolution

Adipose tissue (AT) is a complex connective tissue with a high relative proportion of adipocytes, which are specialized cells with the ability to store lipids in large droplets. AT is found in multiple discrete depots throughout the body, where it serves as the primary repository for excess calories. In addition, AT has an important role in functions as diverse as insulation, immunity and regulation of metabolic homeostasis. The Human Cell Atlas Adipose Bionetwork was established to support the generation of single-cell atlases of human AT as well as the development of unified approaches and consensus for cell annotation. Here, we provide a first roadmap from this bionetwork, including our suggested cell annotations for humans and mice, with the aim of describing the state of the field and providing guidelines for the production, analysis, interpretation and presentation of AT single-cell data.

Gamma-glutamyl cyclotransferase, a molecule identified from the invasive front of follicular thyroid carcinoma, is useful for differential diagnosis of follicular thyroid tumors

We aimed to establish a useful molecular marker for differentiating between follicular thyroid carcinoma (FTC) and follicular adenoma (FA). RNA was extracted from the invasive front and paired tumor center tissues from three FTC cases using laser microdissection for cDNA microarray analysis, revealing high expression of gamma-glutamyl cyclotransferase (GGCT) in the invasive front. Subsequently, immunohistochemical (IHC) staining of GGCT was performed with formalin-fixed paraffin-embedded (FFPE) sections of FTC (n = 32), FA (n = 64), and follicular tumor of uncertain malignant potential (FT-UMP, n = 5). The GGCT expression score (range: 0-300) was calculated by multiplying the intensity score (0-3) and percentage of positive cells. The Ki-67 labeling index was also assessed in 20 FTC and 25 FA cases from the same cohort. The GGCT expression score was higher in FTC than in FA (118.5 ± 51.4 vs. 57.3 ± 34.7, P < 0.0001). With the GGCT expression score, using a cutoff value of 101.1, the differentiation between FTC and FA was possible with a sensitivity of 68.8 % and specificity of 87.5 % (AUC = 0.832). With the Ki-67 labeling index, applying a cutoff value of 4.0 %, the distinction between FTC and FA resulted in a sensitivity of 50.0 % and specificity of 80.0 % (AUC = 0.677). The GGCT expression score was positively related to the Ki-67 labeling index in the FTC cases. (Spearman's ρ = 0.5293, P = 0.0164). Therefore, GGCT is a potential marker for differentiating FTC from FA. The GGCT expression of FTC may be indicative of its invasive and proliferative activity.

Thyroid hemiatrophy associated with papillary thyroid carcinoma

PURPOSE

The present study aimed to investigate CT imaging features, pathological findings, and prognosis in patients with thyroid hemiatrophy (THA) associated with papillary thyroid carcinoma (PTC).

METHODS

This retrospective study included 225 patients with histopathologically proven PTC treated by surgical resection who underwent preoperative CT scanning. On CT images, THA was defined as thyroid parenchymal hemiatrophy on the ipsilateral side of PTC. CT findings, overall survival, and disease-free survival were compared between patients with and without THA. Pathological findings were also assessed in PTCs with and without THA.

RESULTS

THA was observed in 35 of 225 (16%) patients with PTC. Atrophic thyroid parenchyma was observed in the right lobe of 20 patients (57%) and in the left lobe of the remaining 15 patients (43%). With respect to the solid components within PTCs, contrast-enhanced CT attenuation (114.2 ± 18.2 vs. 126.7 ± 31.3 HU; p < 0.05) and CT attenuation change for contrast-enhanced CT minus unenhanced CT (60.2 ± 18.1 vs. 72.3 ± 31.0 HU; p < 0.05) were significantly lower in PTCs with THA than in those without THA. Histopathologically, almost all PTCs with THA (97%) had keloid-like collagen, which is broad bundles of hypocellular collagen with bright eosinophilic hyalinization, typically observed in keloid. However, no significant differences were observed in the prognosis between the two groups.

CONCLUSION

THA was occasionally observed in patients with PTC. Weak contrast-enhancement was distinct characteristic of PTC patients with THA, which is probably caused by keloid-like collagen.

TIROSEC: Molecular, Clinical and Histopathological Profile of Papillary Thyroid Carcinoma in a Colombian Cohort

INTRODUCTION

In Colombia, thyroid cancer ranks among the highest incidences, yet our population lacks studies on its molecular profile. This study aims to characterize clinical, histopathologic and molecular data in a Colombian cohort with papillary thyroid carcinoma (PTC).

METHODS

A retrospective review of clinical history, clinicopathologic characteristics, treatment and 5-10-year follow-up for all patients was done. DNA and RNA were extracted from formalin-fixed paraffin-embedded (FFPE) tissue using the Quick-DNA & RNA FFPE Min iPrep kit (Zymo Research). Next-generation sequencing (NGS) analysis was performed with SOPHiA Solid Tumor Solutions kit (SOPHiA GENETICS). Tumor mutation genomic analysis used SOPHiA DDM™ platform, with descriptive analysis reporting frequencies, means and associations via chi-square analysis.

RESULTS

Among 231 sequenced patients, mean age at diagnosis was 46 (± 12.35) years, with higher frequency in women (81.82%). Two cases were reclassified as non-invasive follicular thyroid neoplasm (NIFT-P); an NRAS mutation was found in one of them. Predominant histologic subtype was classic PTC (57.64%) followed by tall cell (28.82%). Of the 229 sequenced carcinomas, mutations were identified in 186 cases, including BRAF, IDH1, RAS and PIK3CA. Notable copy number variations (CNVs) were PDGFRA, CDK4 and KIT, with RET being the most frequent gene fusion, including CCDC6-RET in two classic subtype cases.

CONCLUSION

This is the first study in Colombia (TIROSEC) to our knowledge that integrates molecular and histopathologic profiles enriching our local comprehension and knowledge of PTC. The identification of target mutations such as BRAF, RET and NTRK fusions holds the potential to guide targeted therapies for tumor recurrence and predict aggressive behavior.

Towards in vivo characterization of thyroid nodules suspicious for malignancy using multispectral optoacoustic tomography

PURPOSE

Patient-tailored management of thyroid nodules requires improved risk of malignancy stratification by accurate preoperative nodule assessment, aiming to personalize decisions concerning diagnostics and treatment. Here, we perform an exploratory pilot study to identify possible patterns on multispectral optoacoustic tomography (MSOT) for thyroid malignancy stratification. For the first time, we directly correlate MSOT images with histopathology data on a detailed level.

METHODS

We use recently enhanced data processing and image reconstruction methods for MSOT to provide next-level image quality by means of improved spatial resolution and spectral contrast. We examine optoacoustic features in thyroid nodules associated with vascular patterns and correlate these directly with reference histopathology.

RESULTS

Our methods show the ability to resolve blood vessels with diameters of 250 μm at depths of up to 2 cm. The vessel diameters derived on MSOT showed an excellent correlation (R2-score of 0.9426) with the vessel diameters on histopathology. Subsequently, we identify features of malignancy observable in MSOT, such as intranodular microvascularity and extrathyroidal extension verified by histopathology. Despite these promising features in selected patients, we could not determine statistically relevant differences between benign and malignant thyroid nodules based on mean oxygen saturation in thyroid nodules. Thus, we illustrate general imaging artifacts of the whole field of optoacoustic imaging that reduce image fidelity and distort spectral contrast, which impedes quantification of chromophore presence based on mean concentrations.

CONCLUSION

We recommend examining optoacoustic features in addition to chromophore quantification to rank malignancy risk. We present optoacoustic images of thyroid nodules with the highest spatial resolution and spectral contrast to date, directly correlated to histopathology, pushing the clinical translation of MSOT.

To Freeze or Not to Freeze? Recommendations for Intraoperative Examination and Gross Prosection of Thyroid Glands

The use of intraoperative consultation for indeterminate thyroid lesions is not advocated but is still requested by some surgeons. Obscured cytomorphology and nonrepresentative sampling limit the specificity of intraoperative assessment. Formalin fixation of thyroid glands before sectioning also minimizes artifacts introduced by fresh sectioning. Inking of thyroid may vary based on institutional preferences and information desired by clinical teams. Sectioning may occur in the conventional transverse method or the modified transverse vertical method to more thoroughly evaluate the lesion's periphery. Gross examination of thyroid lesions should always consider possible high-grade features, such as necrosis or extrathyroidal extension.

Survival prognostic factors for differentiated thyroid cancer patients with pulmonary metastases: A systematic review and meta-analysis

BACKGROUND

The prognostic factors for differentiated thyroid cancer (DTC) patients with pulmonary metastases (PM) remain scantly identified and analyzed. Therefore, this systematic review and meta-analysis were performed to identify and summarize the prognostic factors in adult DTC patients with PM to help distinguish patients with different prognoses and inform the rational treatment regimens.

METHOD

We performed a comprehensive search of the relevant studies published in the Cochrane Library, PubMed, Scopus, Embase, Wanfang database, VIP database, China National Knowledge Infrastructure, and Google Scholar from their inception until February 2021. The pooled hazard ratios (HR) for overall survival and/or progression-free survival (PFS) with 95% confidence intervals were applied to evaluate and identify the potential prognostic factors. Pooled OS at different time points were also calculated for the available data. A random-effects model was used in the meta-analysis.

RESULTS

The review and meta-analysis included 21 studies comprising 2722 DTC patients with PM. The prognostic factors for poor OS were: age over 40 years (HR=7.21, 95% confidence interval [CI] 1.52-34.10, P=0.01, N=788), age over 45 years (HR=2.18, 95% CI 1.26-3.77, P<0.01, N=601), male gender (HR=1.01, 95% CI 1.01-1.19, P=0.03, N=1396), follicular subtype of thyroid cancer (HR=1.63, 95% CI 1.36-1.96, P<0.01, N=2110), iodine non-avidity (HR=3.10, 95% CI 1.79-5.37, P<0.01, N=646), and metastases to other organs (HR=3.18, 95% CI 2.43-4.16, P<0.01, N=1713). Factors associated with poor PFS included age over 45 years (HR=3.85, 95% CI 1.29-11.47, P<0.01, N=306), male gender (HR=1.36, 95% CI 1.06-1.75, P=0.02, N=546), iodine non-avidity (HR=2.93, 95% CI 2.18-3.95, P<0.01, N=395), pulmonary metastatic nodule size over 10mm (HR=2.56, 95% CI 2.02-3.24, P<0.01, N=513), and extra-thyroidal invasion (HR=2.05, 95% CI 1.15-3.67, P=0.02, N=271). The pooled 1, 3, 5, 10, 15, and 20-years OS were 95.24%, 88.46%, 78.36%, 64.86%, 56.57%, and 51.03%, respectively.

CONCLUSIONS

This review and meta-analysis identified the prognostic factors of DTC patients with PM. Notably, FTC, metastases to other organs, and iodine non-avidity were particularly associated with poor prognosis. The identified prognostic factors will help guide the clinical management of DTC patients with PM.

SYSTEMATIC REVIEW REGISTRATION

https://inplasy.com/inplasy-2022-2-0026/, identifier (INPLASY202220026).

Papillary Breast Tumors: Continuing Controversies and Commentary on WHO's 2019 Criteria and Classification

The category of papillary breast tumors includes a limited number of entities. Nonetheless, this relatively uncommon group of tumors seems to instigate a disproportionate degree of diagnostic disquiet. As a group, papillary breast tumors suffer from a relatively high rate of discordant interpretation. The latter is due to the inherent complexity of the lesions compounded by conflicting criteria as well as simmering controversies. For instance, "encapsulated" papillary carcinoma remains contentious with regards to whether these are noninvasive or not, and the assessment of the extent of the invasive versus noninvasive components in many solid papillary carcinomas can be problematic. The latest classification system of breast tumors enunciated by the World Health Organization (WHO), that is, Breast Tumors, which appeared in 2019, mainly sought to incorporate advances in basic and clinical sciences into diagnostic criteria for the entire spectrum of breast neoplasms-including papillary ones. The latter category of tumors is discussed at some length in Breast Tumors; however, it still appears to suffer from some lack of clarity in its subclassification. It is our intent in this communication to provide an overview of the controversies around papillary breast tumors, and offer comments on its coverage in Breast Tumors-so that any tangible or perceived ambiguities therein could be addressed in its next edition.

The Effects of Chronic Lymphocytic Thyroiditis on Clinicopathological Factors In Papillary Thyroid Cancer

INTRODUCTION

This study evaluated the impact of chronic lymphocytic thyroiditis (CLT) on clinicopathological parameters, prognostic outcome and initial treatment responses in patients with papillary thyroid cancer (PTC).

METHODS

A retrospective review was made of 1409 patients with PTC, comprising 443 pathology proven PTC patients with CLT and 447 PTC patients without CLT.

RESULTS

The median follow-up time was 58 (8-380) months and the median age at the time of diagnosis was 43 years. The diagnosis age was significantly lower in patients with CLT (42 vs. 45 years, p:0.001). The preoperative TSH level was found to be significantly higher in CLT patients (1.71 mIU/L vs. 1.28 mIU/L, p<0.001). Multifocality, capsular, lymphovascular and perineural invasion were detected at a higher rate in the group with CLT than in the group without CLT (p:0.015, p:0.024, p:0.004, p:0.039, respectively). No difference was found between the two groups in terms of tumor size, bilaterality, extrathyroidal invasion, lymph node metastasis, disease stage and response to treatment (p>0.05).

CONCLUSION

The results of the present study demonstrated that coexistence of PTC and CLT is very frequent. It was found that patients with PTC and CLT coexistence were diagnosed at an earlier age and the TSH level was higher. Contrary to previous studies, no positive effect of CLT and PTC combination was detected on any clinicopathological factor. In addition, lymphovascular and perineural invasion, which had negative effects on prognosis, was more common in the CLT group.

Intratumoral Heterogeneity in Differentiated Thyroid Tumors: An Intriguing Reappraisal in the Era of Personalized Medicine

Differentiated thyroid tumors (DTTs) are characterized by significant molecular variability in both spatial and temporal intra-tumoral heterogeneity (ITH), that could influence the therapeutic management. ITH phenomenon appears to have a relevant role in tumor growth, aggressive behavior and drug resistance. Accordingly, characteristics and consequences of ITH in DTTs should be better analyzed and understood in order to guide clinical practice, improving survival. Consequently, in the present review, we investigated morphological and molecular ITH of DTTs in benign, borderline neoplasms and in malignant entities, summarizing the most significant data. Molecular testing in DTTs documents a high risk for recurrence of cancer associated with BRAF^V600E, RET/PTC 1/3, ALK and NTRK fusions, while the intermediate risk may be related to BRAF^K601E, H/K/N RAS and PAX8/PPARγ. In addition, it may be suggested that tumor genotype is associated with peculiar phenotype.

DNA FISH Diagnostic Assay on Cytological Samples of Thyroid Follicular Neoplasms

Simple Summary

Cytopathology cannot distinguish benign from malignant follicular lesions in 20–30% of cases. These indeterminate cases includes the so-called follicular neoplasms (FNs) according to The Bethesda System for Reporting Thyroid Cytopathology. Frozen samples from 66 classic follicular adenomas (cFAs) and carcinomas (cFTCs) studied by array-comparative genomic hybridization identified three specific alterations of cFTCs (losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X) confirmed by fluorescent in situ hybridization (FISH) in a second independent series of 60 touch preparations from frozen samples of cFAs and cFTCs. In a third independent set of 27 cases of already stained pre-operative fine-needle aspiration cytology samples diagnosed as FNs and histologically verified, FISH analysis using these three markers identified half of cFTCs. Specificity of our assay for identifying cFTCs is higher than 98% which might be comparable with BRAF^600E testing in cases of suspicion of classic papillary thyroid carcinomas.

Abstract

Although fine-needle aspiration cytology (FNAC) is helpful in determining whether thyroid nodules are benign or malignant, this distinction remains a cytological challenge in follicular neoplasms. Identification of genomic alterations in cytological specimens with direct and routine techniques would therefore have great clinical value. A series of 153 cases consisting of 72 and 81 histopathologically confirmed classic follicular adenomas (cFAs) and classic follicular thyroid carcinomas (cFTCs), respectively, was studied by means of different molecular techniques in three different cohorts of patients (pts). In the first cohort (training set) of 66 pts, three specific alterations characterized by array comparative genomic hybridization (aCGH) were exclusively found in half of cFTCs. These structural abnormalities corresponded to losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X. The second independent cohort (validation set) of 60 pts confirmed these data on touch preparations of frozen follicular neoplasms by triple DNA fluorescent in situ hybridization using selected commercially available probes. The third cohort, consisting of 27 archived cytological samples from an equal number of pts that had been obtained for preoperative FNAC and morphologically classified as and histologically verified to be follicular neoplasms, confirmed our previous findings and showed the feasibility of the DNA FISH (DNA fluorescent in situ hybridization) assay. All together, these data suggest that our triple DNA FISH diagnostic assay may detect 50% of cFTCs with a specificity higher than 98% and be useful as a low-cost adjunct to cytomorphology to help further classify follicular neoplasms on already routinely stained cytological specimens.

Integrin β4 Is an Effective and Efficient Marker in Synchronously Highlighting Lymphatic and Blood Vascular Invasion, and Perineural Aggression in Malignancy

Lymphovascular invasion (LVI) and perineural invasion (PNI) are 2 important pathologic parameters and need to be accurately assessed in multiple malignancies. Integrin β4, a member of the integrin family, has been reported to be positively expressed in vascular endothelia, peripheral nerves, and a collection of epithelia. However, little is known about the effectiveness of β4 immunostaining on the recognition of LVI and PNI. Herein, we explored the applicability of β4 immunostaining in stomach, thyroid, and breast cancers. Parallel immunostaining of D2-40, CD34, and S-100 was performed as controls for lymphatic endothelia, vascular endothelia, and neural fibers, respectively. The results demonstrated that β4 concurrently stained the lymphatic and vascular endothelia, and the peripheral nerves. Both LVI and PNI were clearly and accurately outlined by β4 immunostaining. β4 was also expressed in the majority of tumor cells, enabling recognition of LVI and PNI encroached by small tumor clusters. In contrast to D2-40 and CD34, β4 staining was not observed in stromal cells, and therefore it facilitated differentiation between the shrinkage cleft and LVI. According to our results, β4 staining strikingly increased the diagnostic accuracy and interobserver concordance for LVI and PNI compared with hematoxylin and eosin staining alone. Finally, the applicability of β4 was confirmed in 9 other types of malignancies, including cancers of the colon, prostate, esophagus, lung, kidney, uterus, tongue, bladder, and liver. Collectively, β4 is a reliable marker for synchronous detection and diagnosis of LVI and PNI.

Invasion in thyroid cancer: Controversies and best practices

Invasion is a key feature of malignancy and an important element in the classification, risk-stratification, and staging of thyroid cancers. However, the histopathologic criteria for tumor capsular invasion, angioinvasion, and extrathyroidal extension (ETE) have varied among pathologists, both in practice as well as in studies assessing the clinical significance of these findings. In this review, we provide historic context for the controversies surrounding the definition of invasion in thyroid neoplasms and highlight recent efforts to standardize how pathologists report capsular invasion, angioinvasion, and ETE. We offer practical suggestions for distinguishing invasion from its mimics and provide an algorithmic approach for classifying thyroid tumors based on integration of tumor invasiveness, nuclear atypia, and architectural pattern.

Prognostic Significance of Extent of Invasion in Poorly Differentiated Thyroid Carcinoma

Background: The 2017 World Health Organization (WHO) Classification of Tumors of Endocrine Organs defines poorly differentiated thyroid carcinoma (PDTC) as a tumor with conventional criteria of malignancy (capsular penetration or vascular invasion) with solid, insular, or trabecular growth, a lack of nuclear features of papillary thyroid carcinoma, and increased mitotic activity, tumor necrosis, or convoluted nuclei. The extent of invasion has been shown to be prognostic in follicular thyroid carcinoma and Hürthle cell carcinoma. Our aim was to evaluate how extent of invasion impacts clinical outcome for PDTC. Methods: We retrospectively identified 47 consecutively diagnosed cases of PDTC that were resected between 2005 and 2018. All cases were reviewed to confirm that the tumors met the 2017 Endocrine WHO criteria of PDTC. In addition, tumors were categorized as follows: encapsulated with capsular penetration only, encapsulated with focal vascular invasion (fewer than four foci), encapsulated with extensive vascular invasion (four or more foci), or widely invasive. Histopathologic characteristics and clinical outcome data were recorded. Results: A total of 47 cases of PDTC, including 15 oncocytic tumors, were identified from 28 (60%) women and 19 (40%) men (mean age of 57 years at diagnosis). The mean tumor size was 4.3 cm. Mitoses numbered 8 per 10 high-power fields (HPF) on average (range: 1-34), and necrosis was present in 21 (45%) cases. Eight (17%) cases were encapsulated with capsular penetration only, 5 (11%) were encapsulated with focal vascular invasion, 18 (38%) were encapsulated with extensive vascular invasion, and 16 (34%) were widely invasive. Of the 42 (89%) patients with follow-up data, 7 (17%) died of disease (with a mean survival time of 6.4 years), 11 (26%) have distant metastatic disease, and 24 (57%) have no evidence of disease (mean follow-up 5.6 years). Eight (19%) patients presented with M1 disease at diagnosis. The 5-year disease-free survival (DFS) for patients with M0 disease at diagnosis was 100% for patients with tumors with capsular invasion only or focal vascular invasion (n = 7), 73% for patients with encapsulated tumors with extensive vascular invasion (n = 11), and 17% for patients with widely invasive PDTCs (n = 6). DFS estimates by Kaplan-Meier analysis were significantly different between these groups (p = 0.0016). Conclusions: Extent of invasion appears to be an important parameter that affects clinical outcome for patients with PDTC. In our cohort, patients with encapsulated PDTC with capsular invasion only or focal vascular invasion had an excellent outcome.

Critical Prognostic Parameters in the Anatomic Pathology Reporting of Differentiated Follicular Cell-Derived Thyroid Carcinoma

In the past decades, pathology reporting on thyroid carcinoma has evolved from a narrative approach to structured synoptic reports. Many histologic variables are present in the current synoptic reports that are crucial elements for initial risk stratification and clinical management. In this review, we compare and summarize the key prognostic pathologic characteristics utilized by the most influential clinical and pathologic guidelines from the American Thyroid Association (ATA), the National Comprehensive Cancer Network (NCCN), the current World Health Organization (WHO) classification of endocrine tumors (fourth edition), the current American Joint Committee on Cancer (AJCC) staging system (eighth edition), the College of American Pathologists (CAP) protocol, and the International Collaboration on Cancer Reporting (ICCR) dataset. The aim is to provide a comprehensive review focused on the definitions and prognostic impacts of these crucial pathologic parameters.

[Tumors of the thyroid gland. Proposal for the management and study of samples from patients with thyroid neoplasms]

The recent changes in the classification and staging of thyroid tumors have arisen from the need to provide an adequate response to the exponential increase of thyroid cancer, which, however, has not been accompanied by an increase in mortality. These changes pretend to reduce overdiagnoses of malignancy, unnecessary treatment, side effects as well as cost for the health system. To this end, this article reviews recommendations for the management of thyroid surgical pathology samples with emphasis on the new terminology of the WHO classification. The basic criteria for the diagnosis of malignancy in well-differentiated thyroid carcinomas are reviewed and the criteria for NIFTP (non-invasive follicular tumor with papillary-like nuclear features) diagnosis are updated. Recommendations for the elaboration of the pathological report are also included.