Endocrine Pathology最新文献

The literature emphasizes that pulmonary ectopic Cushing syndrome (ECS) is associated not only with neuroendocrine tumors (NETs), but also with small cell lung carcinomas (SCLCs). This statement is debatable, because extrapulmonary ECS is associated with NETs in the vast majority of cases and very rarely with neuroendocrine carcinomas (NECs). Therefore, we critically reviewed the literature on SCLCs associated with ECS (ECS-SCLC) and performed immunohistochemical analysis of ACTH expression in 155 resected SCLCs and 158 pulmonary NETs. The literature search revealed that 90% of the 205 ECS-SCLC patients identified between 1952 and 2023 had no or poor-quality histologic images, so the diagnosis of SCLC could not be confirmed. Review of the 20 reports (10%) with histologic images revealed that 18/20 (90%) had to be reclassified as "probable NET", of which 5/18 (28%) showed spindle cell morphology, while only 2 cases were qualified as "SCLC compatible" due to their pleomorphic cell features. Immunohistochemically, 5/155 (3%) resected SCLCs, all without ECS, showed weak single cell ACTH expression, whereas in the NET cohort, 61/158 (39%) tumors expressed ACTH, of which 4 (3%) were associated with ECS. Both observations, the literature review, which casts doubt on previously reported data regarding the frequency of SCLC in ECS, and the immunohistochemical study, suggest that there is limited evidence that SCLC is the cause of ECS.

Few studies have analyzed the prevalence of TERT amplification in thyroid cancer, showing discrepancies in various topics. The impact on tumor recurrence and patient survival in papillary thyroid carcinoma (PTC) remains unknown. Thirteen cancer cell lines and 215 tumor samples from 91 patients, who underwent surgery for PTC (41), poorly differentiated thyroid carcinoma (PDC = 15), or anaplastic thyroid carcinoma (ATC = 35), were analyzed. Clonality, spread with tumor dedifferentiation or metastatic PTC cells, and coexistence with TERTp, BRAF, RAS, and PIK3CA mutations were also investigated. TERT amplification was found in 17%, 20%, and 17% of the PTC, PDC, and ATC, respectively. It was more frequent in follicular variant PTC and PTC with distant metastases (86%, P = 0.0448). The cell lines HTh74, SW1736, and T242 had amplification. In PTC, TERT amplification was a subclonal event. The increase in TERT copy number spread in all cases with metastatic PTC cells. In 67% of the PDC and 100% of the ATC, TERT activation segregated with tumor dedifferentiation. TERT amplification correlated with TERTp mutations in PTC (P = 0.0313) and PIK3CA mutations in ATC (P = 0.0272). TERT amplification significantly correlated with vascular invasion (P = 0.03637), distant metastases at diagnosis and/or follow-up (P = 0.04482), metachronous distant metastases (P = 0.03131), death patient status (P = 0.000829), stage at diagnosis (P = 0.01995), and stage III/IV at last follow-up (P = 0.01552). TERT amplification associated independently with tumor-related recurrence and death. Our study shows that PTC can be stratified into clinically prognostic relevant categories based on the presence or not of TERT amplification in the cells.

Anaplastic thyroid carcinoma (ATC) is an aggressive malignancy with a poor prognosis. Despite its rarity, identifying predictive molecular markers that distinguish ATC from follicular cell-derived non-anaplastic thyroid carcinomas is critical for improving diagnosis and treatment strategies. This study aimed to identify and validate key mRNA and protein markers associated with ATC progression and dedifferentiation. We performed spatial transcriptomic analysis on an index case of ATC coexisting with papillary thyroid carcinoma (PTC) and identified eight differentially expressed mRNA markers. These findings were validated in a large cohort using immunohistochemistry on tissue microarrays across various thyroid tumor types, including follicular adenoma, PTC, poorly differentiated thyroid carcinoma, medullary thyroid carcinoma, and ATC. Additionally, the impact of BRAF p.V600E mutation status on these markers was evaluated. COL7A1, LAMC2, SPHK1, and SRPX2 mRNA and protein levels were significantly overexpressed in ATCs. Conversely, CD24, EPHX1, GPX3, and RBM47 mRNA and protein levels were markedly downregulated in ATCs. Functional enrichment analysis, based on mRNA expression data, identified the role of these proteins in tumor invasion, epithelial-mesenchymal transition, extracellular matrix remodeling, and immune evasion. The expression levels of these markers were independent of BRAF p.V600E mutation status, highlighting their potential as diagnostic markers. In summary, this study identified eight molecular markers that can distinguish ATC from other thyroid tumors. The validation of these markers at both the mRNA and protein levels underscores their clinical relevance in ATC diagnosis and tumor characterization. These findings provide a foundation for future biomarker-driven diagnostic and therapeutic strategies for ATC.

Identifying risk factors in papillary thyroid carcinoma (PTC) that warrant more aggressive treatment is paramount. Importantly, the prevalence and clinical significance of BRAF p.V600E mutation in PTC remain debatable. This study aims to determine the association of BRAF p.V600E with demographic and clinicopathologic characteristics, including recurrence. Single institution data from consecutive PTC patients with BRAF p.V600E immunohistochemistry and/or molecular testing was collected between 2018 and 2022, including BRAF status, morphologic subtype, TN category, tumor size, nodal disease burden, tumor multifocality, extrathyroidal extension, treatment, follow-up time, loco-regional and distant recurrence, and mortality. This study included 301 patients, 30% male. The majority had BRAF p.V600E mutation (78.7%), and BRAF p.V600E was associated with morphologic subtype (p < 0.001), with 88% of classic subtype PTCs, 38% of PTCs with extensive follicular growth, and 100% of tall cell subtype expressing BRAF p.V600E. BRAF p.V600E was not associated with tumor size (p = 0.696) or nodal disease burden (p = 0.962). On multivariate analysis using Cox proportional hazard model, large volume nodal disease burden (HR 3.37, 95%CI 1.49-7.64, p = 0.004) and male gender (HR 2.29, 95%CI 1.23-4.26, p = 0.009) were significantly associated with recurrence. BRAF p.V600E (HR 0.71, 95% CI 0.31-1.65, p = 0.4) was not significantly associated with recurrence. In conclusion, presence of BRAF p.V600E in the absence of high risk histologic features does not have an impact on PTC recurrence, and thus, its utility in risk stratification is questionable in the setting of other clinicopathologic risk factors.

The 2023 Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) update refines the atypia of undetermined significance (AUS) category by subclassifying it into AUS-nuclear atypia (AUS-N) and AUS-other atypia (AUS-O) based on risk of malignancy, to enhance clarity of diagnosis and patient management. This study evaluates the impact of AUS subclassification on malignancy risk prediction in thyroid nodules. A total of 118 AUS cases were analyzed for subclassification using the nuclear scoring (NS) system to evaluate nuclear features, along with the ultrasonography-based Korean Thyroid Imaging Reporting and Data System (K-TIRADS) for risk stratification, and BRAF V600E mutation testing. Logistic regression and ROC curve analyses were used to identify predictors of malignancy and to assess model performance. The AUS category was divided into AUS-N and AUS-O, with AUS-N having a significantly higher risk of malignancy (ROM) (78.1%) compared to AUS-O (27.3%). The subcategories AUS-N1, N2, and N5 showed significantly high ROM (96.9%, 71.7%, and 90.0%), whereas AUS-N3 and N4 showed lower ROM (20.0% and 33.3%). The NS system standardized the assessment of nuclear atypia, reducing interobserver variability and improving diagnostic reproducibility. BRAF V600E mutation, present in 28.1% of AUS-N cases but absent in AUS-O cases, was a strong predictor of malignancy. Models integrating imaging, detailed cytologic subclassification, and molecular findings achieved high specificity (81.0-86.5%) but moderate sensitivity (58.0-61.3%). These findings support the use of AUS subclassification and molecular testing for BRAF V600E mutation to improve ROM prediction and are consistent with the 2023 TBSRTC emphasis on tailored risk stratification.

Oncocytic adrenocortical carcinoma (OAC) is a rare variant of conventional adrenocortical carcinoma (ACC), characterized by oncocytic tumor cells comprising more than 90% of the tumor. Due to its rarity, there is a lack of reliable data on the clinicopathological features and outcomes of OAC. The aim of this study was to assess the clinical presentation, treatment modalities, and outcomes of patients with OAC, comparing these results with a cohort of patients with conventional ACC. Data from 9 referral centers in Italy on 44 patients with OAC were retrospectively analyzed and compared with data from 145 patients with conventional ACC. Patients with OAC had a smaller median tumor size, more favorable resection margin status, and lower incidences of venous invasion and persistent/recurrent disease during follow-up. Additionally, patients with OAC exhibited longer times to progression (TTP) and overall survival (OS) compared to patients with conventional ACC. Multivariable analyses identified Ki67 and tumor size as features independently associated with disease progression during post-surgical follow-up, while Ki67 and distant metastases at diagnosis were independently associated with OS in OAC patients. After complete tumor removal, the risk of recurrent disease was higher in patients with either Ki67 ≥ 20% or ENSAT stage III/IV. OAC appears to have a more indolent clinical course and better prognosis than conventional ACC. Similar to conventional ACC, Ki67 remains a significant prognostic marker for OAC and, along with ENSAT stage, serves as a reliable biomarker for identifying patients who may benefit from adjuvant mitotane therapy.

Tissue section thickness (TST) is an understudied variable in digital pathology that significantly impacts both visual assessments and computational analyses. This study systematically examines the effects of TST on whole slide images (WSIs) and nuclear-level features using thyroid tissue samples (n = 144) prepared at thicknesses ranging from 0.5 to 10 µm. By minimizing preanalytical variables and batch effects, we aimed to isolate TST as the primary factor in our experiment. Visual assessments indicated that thinner Sects. (0.5-3 µm) were more transparent with distinct cellular features, while thicker Sects. (5-10 µm) appeared darker with increased staining intensity and artifacts. Quantitative analyses were performed using open-source tools such as HistoQC for WSI quality control, HoverNet for nuclear segmentation, and feature extraction with Scikit-learn and Mahotas. Both WSI and nuclear-level metrics were significantly influenced by TST. The Haralick texture feature of difference entropy, which measures texture complexity, showed a 13.7% decrease in nuclei as TST increased, indicating fewer complex textures in thicker sections. Additionally, intensity decreased substantially with thicker tissue, dropping by 26.1% at the WSI level and 30.4% at the nuclear level. WSI contrast exhibited an increase of 92.6% when transitioning from 0.5 to 10 µm. These findings demonstrate that variations in TST can obscure or alter the appearance of biological signals, complicating both visual diagnostics and computationally extracted features. The study highlights the need for standardized tissue section thickness protocols, alongside consistent reporting of these standards, to ensure accuracy and reliability in both visual evaluations and computational analyses within digital pathology workflows.

Delta-like ligand 3 (DLL3) is frequently expressed in pulmonary small cell neuroendocrine carcinoma (SCNEC) and has emerged as a promising therapeutic target. However, limited data on DLL3 expression in other neuroendocrine neoplasms (NEN), such as extrapulmonary SCNEC, large cell neuroendocrine carcinomas (LCNEC), mixed neuroendocrine-non-neuroendocrine neoplasms (MiNEN), gastroenteropancreatic neuroendocrine tumours (GEP-NET), and pulmonary carcinoids, impedes an estimation if other types of NEN might be suitable candidates for anti-DLL3 therapies. We evaluated DLL3 expression in 1294 NEN and 479 non-neuroendocrine carcinomas, correlating the findings with histological subtypes, tumour localisation, and overall survival (OS). Furthermore, we explored the concordance of DLL3 expression during metastatic progression in 67 paired primary NEN and metastases. DLL3 expression was significantly higher in NEC (64.0%) compared to GEP-NET and pulmonary carcinoids (10.1%, p < 0.001), particularly in SCNEC (80.4%), followed by LCNEC (62.6%) and MiNEN (28.6%). DLL3 was common in pulmonary carcinoids (41.5%), but rare in GEP-NET (5.1%) and non-neuroendocrine carcinomas (1.3%). Overall DLL3 expression was highly concordant between metastases and corresponding primary NEN (92.5%, p < 0.001). In univariable analyses, DLL3-expressing pulmonary carcinoids (p = 0.005) and GEP-NET (p = 0.018) were associated with decreased OS, but this was not retained in multivariable analyses adjusting for stage and grade (p = n. s.). No prognostic impact was observed in pulmonary (p = 0.708) or GEP-NEC (p = 0.87). Our study highlights significant differences in DLL3 expression across NEN subtypes and localisations, with largely concordant expression in metastases. DLL3-based therapies may be effective in many NEC and pulmonary carcinoids, while DLL3 appears to be a minor therapeutic target for GEP-NET and non-neuroendocrine carcinomas.

An integrative histologic and molecular classification of thyroid tumors has become clinically relevant due to the potential role in risk stratification and selection of targeted therapy. In this review, we discuss the applications of six "next-generation" immunohistochemical markers, namely BRAF V600E (clone VE1), RAS Q61R (clone SP174), pan-TRK (clone EPR 17341), ALK (clones 5A4 or D5F3), PTEN, and β-catenin in the pathologic diagnosis and molecular classification of thyroid tumors. These biomarkers allow the in situ examination of tumor tissue and assist in the diagnosis and pathologic staging by highlighting tumor border and patterns of invasion, identifying isolated tumor cells in lymph nodes, distinguishing lymph node metastasis from benign intranodal thyroid inclusions, and diagnosing multicentric thyroid carcinomas with discordant molecular drivers. Furthermore, it can identify specific thyroid neoplasms that may occur sporadically or may be associated with hereditary syndromes. The next-generation immunohistochemistry provides a novel solution to challenging issues in thyroid pathology and fast turn-around time for accurate molecular classification and further guidance of therapeutic management.

NTRK fusions are rare but recurrent driver alterations in papillary thyroid carcinoma (PTC), with therapeutic significance due to the availability of targeted TRK inhibitors. Pan-TRK immunohistochemistry (IHC) provides a practical approach for the identification of NTRK fusions; however, its application and reliability in routine pathology require further exploration. This study is aimed at evaluating the diagnostic utility of pan-TRK IHC for detecting NTRK fusions in PTC, assessing its correlation with histopathologic features, and developing a diagnostic algorithm. We analyzed 107 BRAF p.V600E-negative PTC cases using pan-TRK IHC, correlating staining patterns with molecular data and histopathologic features. RNA-based targeted sequencing confirmed gene fusions. NTRK fusion-positive tumors were enriched in distinct histopathologic features, including BRAF-like PTC with predominant follicular architecture, clear cells, and secretory-like cells. Findings such as tumor cell stratification, glomeruloid structures, and papillae with subfollicle formation (microfollicles within papillary structures) were associated with both NTRK and RET fusion-positive PTCs. Correlation of pan-TRK IHC and molecular testing results identified non-specific reactivity or false positivity in 62% of pan-TRK IHC-positive PTCs, including cases with RET fusions, BRAF fusion, or no detectable fusion. However, pan-TRK IHC with high H-scores (≥ 110) was observed exclusively in cases with NTRK fusions. For cases with lower H-scores (< 110), integrating histopathologic features improved the identification of fusion-driven PTCs. While our series further supports the limitations of pan-TRK IHC, a diagnostic algorithm that combines pan-TRK IHC H-scores and histopathologic patterns improved the triaging of NTRK molecular testing of BRAF p.V600E-negative PTCs when a stepwise approach is undertaken. This study also demonstrated that TRK protein localization may vary with tumor progression and dedifferentiation.