Virchows Archiv最新文献

Lung cancer is typically classified based on morphological characteristics and immunoprofile. When histologic differentiation is difficult, immunohistochemical staining serves as a valuable diagnostic tool. Although most cases show distinct marker expression patterns, rare instances exhibit co-expression of both TTF-1 and p40. Moreover, for this particular subtype of non-small cell lung cancer (NSCLC), no clear demarcation is provided in the World Health Organization (WHO) classification system. In this study, we first conducted a comprehensive literature review to summarize previously reported cases and constructed survival curves for this rare subtype. Subsequently, we collected four additional cases of lung cancer exhibiting this uncommon co-expression pattern, along with four cases of adenosquamous carcinoma (ASC) for comparative analysis, aiming to further characterize their distinguishing clinicopathological features. Whole-exome sequencing (WES) was performed to establish a comprehensive mutational landscape of these tumors. Lung cancers with co-expression of TTF-1 and p40 exhibit a poorer prognosis compared with conventional adenocarcinoma (ADC) and squamous cell carcinoma (SCC). TP53 represents the most frequently mutated gene in this subtype. Notably, SYNE1, TMEM132C, and TNN were identified as characteristic mutations, defining a distinct mutational profile that sets this rare subtype apart from both SCC and ADC. Our findings highlight that NSCLC with diffuse co-expression of TTF-1 and p40 probably constitutes a distinct clinicopathological subtype with rapid clinical progression and poor prognosis, defined by unique morphological characteristics, a biphenotypic immunoprofile, and specific molecular alterations.

The objective of this study was to analyze the diagnostic role of HEG homolog 1 (HEG1) in cancers affecting the serosal cavities. HEG1 protein expression by immunohistochemistry was analyzed in 534 specimens (341 effusions and 193 surgical specimens). Effusions consisted of 151 tubo-ovarian carcinomas, 59 breast carcinomas, 44 mesotheliomas, 37 lung carcinomas, 29 uterine corpus and cervical carcinomas, 17 gastrointestinal carcinomas and 4 genitourinary carcinomas. Surgical specimens consisted of 139 tubo-ovarian carcinomas, 42 mesotheliomas, 7 multicystic mesothelial proliferations and 5 papillary mesothelial tumors. HEG1 expression was found in 43/44 (98%) mesothelioma effusions and 39/42 (93%) surgical mesothelioma specimens, as well as all multicystic and papillary mesothelial tumors. HEG1 was infrequently expressed in breast carcinoma (4/59; 7%), lung carcinoma (2/37; 5%) and cervical/uterine carcinoma effusions (3/29; 10%), but was often detected in tubo-ovarian carcinoma effusions (80/151; 53%) and surgical specimens (99/139, 71%). HEG1 was additionally consistently expressed by reactive mesothelial cells in effusions and in endothelial cells in surgical specimens. HEG1 had sensitivity of 95% for diagnosing malignant mesothelioma in all studied specimens, with a specificity of 38% in the differential diagnosis from tubo-ovarian carcinoma and 93% in the differential diagnosis from non-tubo-ovarian carcinomas. Of 179 HEG1-positive carcinomas, 172 expressed the epithelial marker claudin-4. In conclusion, HEG1 is a highly sensitive marker of both benign and malignant mesothelial cells. It shows high specificity in the differentiation of mesothelioma from lung or breast carcinoma but is of little value in differentiating mesothelioma from tubo-ovarian carcinoma. The potential role of HEG1 as vascular marker merits further research.

Homologous recombination deficiency (HRD) testing may be used to stratify ovarian carcinoma (OC) patients for PARP inhibitor therapy. In the Netherlands, different NGS-based assays are used to assess genomic instability as a hallmark of HRD. We evaluated the uniformity of HRD testing. Firstly, interlaboratory assessments of 10 tumors were performed in 8 centers. 71 out of the 77 (92%) successful tests were concordant. Results were more consistent in OC with a pathogenic variation (PV) or promoter methylation of a homologous recombination repair (HRR) gene (97%) than in those without (87%). Secondly, concordance between BRCA1/RAD51C promoter methylation and HRD was assessed in 244 samples without a PV in HRR genes. BRCA1/RAD51C promoter methylation was present in 38 out of 100 (38%) samples classified as HRD, and absent in all (n = 144) non-HRD samples (p < 0.001). Lastly, pathology reports from 765 HRD tests were reviewed to evaluate routine diagnostics. Testing was successful in 695 (91%) cases. HRD detection rates were higher in high-grade serous OC compared to other histological subtypes (49% versus 12%, p < 0.001). The five HRD assays varied significantly in HRD detection rates in high-grade serous OC. The results support the applicability of genomic instability analyses to assess HRD, while also highlighting the need to improve harmonization across different assays when HRD is used for therapeutic decision making.

A translational gap exists in Burkitt leukemia (B-AL) and Burkitt lymphoma (B-Ly) regarding miRNAs associated with clinicopathological features and outcome. The aim of this study was to evaluate differential miRNA expression in a single-center series of pediatric B-AL/B-Ly. Expression profiles of 800 miRNAs in 33 B-AL/B-Ly samples were evaluated using the NanoString nCounter System. Further validation was performed by qPCR utilizing miRNA-specific TaqMan assays. Significantly expressed miRNAs in B-AL/B-Ly were evaluated in silico to identify predicted targeted cancer-related pathways. Analysis of miRNAs deregulated in B-AL/B-Ly compared to normal control lymphoid tissue (NCLT) identified a consistent set of differentially expressed miRNAs, including miR-494-3p, miR-4286, and miR-19a-3p among the higher expressed miRNAs and miR-150-5p, miR-450b-5p, and miR-342-3p among the lower expressed miRNAs in B-AL/B-Ly compared to NCLT (FC > 1.5, p-adj < 0.05). In silico, the main predicted cancer-related signaling pathways targeted by these miRNAs included the MAPK, PI3K-Akt, JAK-STAT, VEGF, TP53, Fas, TGF-β, and MYC signaling pathways (p-adj < 0.05). B-AL and B-Ly segregated into two major miRNA clusters with sets of significantly overexpressed miRNAs (miR-223-3p, miR-451a, miR-150-5p, miR-144-3p, miR-142-3p, and miR-15a-5p) and lower expressed miRNAs (miR-494-3p, miR-4286, miR-1915-3p, miR-125b-5p, and miR-100-5p) in B-AL compared to B-Ly (FC > 1.5, p-adj < 0.05). Notably, significant downregulation of miR-10a-5p (FC > 1.5, p-adj < 0.05) was observed in the unfavorable outcome group. In summary, new miRNA signatures of relevance in B-AL and B-Ly could be recognized in this study. Studies in larger cohorts are required to further validate these findings.

VGLL3 (encoding the mammalian Vestigial-like 3 transcriptional cofactor) has emerged as a fusion partner in hybrid nerve sheath tumors and in rare spindle cell rhabdomyosarcomas (RMS) of the head and neck. We herein describe a new EP300::VGLL3 RMS and review/update reported cases (total: 6) to reappraise their outcome. All six reported EP300::VGLL3 fusion RMS cases originated exclusively in the tongue musculature of adult males at a median age of 48 years (range, 36-59). Nonradical surgery was the initial treatment in most cases, followed by variable re-excisions in most. Incomplete adjuvant chemotherapy was given to one patient. No metastases were recorded, and all patients with follow-up were disease-free at last follow-up (12, 34, 36, and 48 months). Histologically, all tumors displayed bland spindled to ovoid plump cells lacking clear-cut rhabdomyoblastic features and disposed into fascicular and storiform patterns. The tumor margins were infiltrating with entrapment of skeletal muscle fibers. Overtly malignant cytology, brisk mitotic activity, necrosis, lymphovascular, and perineural invasion were absent. Immunohistochemistry was consistently positive for desmin (6/6), and variably myogenin (6/6), myoD1 (4/4), and SMA (5/6). Fusion breakpoints were identical among all cases (EP300ex31::VGLL3ex2). Given their indolent course after local excision alone, the noncommitted term EP300::VGLL3-fused rhabdomyoblastic tumor might be more appropriate for these tumors than the original RMS terminology to avoid overprognostication/overtreatment that the "rhabdomyosarcoma" label would imply. Reporting more cases is mandatory to elucidate the full anatomic and biological spectrum of this morphologically, anatomically, and genetically unique entity.

Cancer progression is driven by the accumulation of genetic variants, with technological advances increasing their detection. Precise variant interpretation is essential for clinical decision-making, necessitating robust quality assurance programmes. However, variability in interpretation can influence clinical outcomes. This study examines factors contributing to interpretation variability across French laboratories and evaluates the role of EQA schemes in enhancing consistency. Five-year data from the Gen&Tiss EQA programme (2018-2023) focusing on pathogenicity and actionability was analysed. Forty-four participants evaluated 75 variants in colon, lung, and melanoma cancer, while 17 evaluated 50 variants in ovarian cancer. The criteria included the entity responsible for post-analysis, MTB consultations, access to the private French OncoGenetics (FrOG) germline variant database, laboratory activity levels, type of institution, and interpretation complexity. Over the study period, laboratory performance improved significantly, with annual increases of 2.6% in multiparametric pathogenicity and 6.3% in actionability. Laboratories with dedicated somatic genetics services achieved the highest pathogenicity scores. While MTB consultations had inconsistent effects on variant interpretation, access to FrOG database was associated with higher pathogenicity scores in the ovarian programme. Additionally, higher laboratory activity correlated with improved interpretation accuracy, and increased interpretation complexity was linked to lower pathogenicity scores. These findings highlight structural factors affecting interpretation, but further investigation is needed at the individual level to inform policy and training strategies.

Steroid-associated osteonecrosis of the femoral head (SONFH) is closely related to ischemia after corticosteroid treatment as well as the subsequent inflammatory response and oxidative stress. This study examined the temporal and spatial expression of high mobility group box 1 (HMGB1) and peroxiredoxin 4 (PRDX4) in SONFH lesions using immunohistochemistry. Tissue samples from SONFH patients undergoing total hip arthroplasty were compared with those from osteoarthritis (OA) controls. The expression of PRDX4 was significantly reduced in SONFH and was inversely correlated with the oxidative DNA damage marker 8-Hydroxy-2'-deoxyguanosine (8-OHdG). Notably, PRDX4 is strongly expressed in osteoblasts and chondrocytes within callus tissue at the necrotic-viable bone interface, implicating its role in promoting repair through the suppression of oxidative stress. In contrast, most SONFH cases exhibit nuclear-to-cytoplasmic translocation of HMGB1, consistent with its function as a damage-associated molecular pattern (DAMP) that drives inflammatory responses. These findings indicate that HMGB1 acts as an inflammatory mediator during the early phase of SONFH, whereas PRDX4 functions as an oxidative stress regulator during the repair process. Together, these molecules appear to act in a complementary manner to orchestrate the transition from inflammation to tissue regeneration. Their expression dynamics may serve as potential factors for disease progression and reparative activity, while therapeutic strategies targeting HMGB1 signaling or augmenting the expression of PRDX4 may represent promising avenues for intervention.

Metabolic renal cell carcinomas (RCC) deficient in succinate dehydrogenase (SDH) or fumarate hydratase (FH) are rare but clinically significant entities formalized in the last WHO classification. Their recognition typically starts from morphology and is corroborated by targeted immunohistochemistry (IHC) and, where appropriate, molecular and germline testing. In routine practice, however, implementation may be uneven. Hence, we conducted a nationwide, web-based survey (made by 25 items) among members of the Italian Study Group of Uropathology (GIUP) to map real-world awareness, diagnostic pathways, and test availability across Italian centers. Twenty-one pathologists responded; 18/21 (85.7%) reported dedicated uropathology practice with heterogeneous seniority (≤ 5 years, 28.6%; 5-10 years, 19.0%; 10-20 years, 14.3%; > 20 years, 38.1%). Despite substantial renal-tumor workloads (12/20, 57.1% handled > 100 cases in the previous 5 years), direct exposure to metabolic RCCs remained limited (FH-deficient ≥ 1 case, 11/21, 52.4%; SDH-deficient ≥ 1 case, 9/21, 42.9%). Suspicion was predominantly morphology-led: for SDH-deficient RCC, morphology ranked first in 16/21 (76.2%) with the commonest sequence morphology > age > number of lesions (76.2%); for FH-deficient RCC, morphology was top-ranked in 19/21 (90.5%). Key morphologic cues were mixed architectural patterns/papillary elements/macronucleoli for FH-deficient RCC, and eosinophilic cytoplasm with solid-alveolar architecture for SDH-deficient RCC. IHC mirrored these priorities (FH top for FH-deficient, 85.7%; SDHB top for SDH-deficient, 76.2%), whereas 2-succinocysteine (2SC) was rarely available (1/21, 4.8%). Critically, this FH-loss-only workflow can miss non-truncating FH variants (FH immunoreactive but enzymatically inactive) tumors, contributing to under-recognition. Molecular testing would be requested in all suspected cases by 12/21 (57.1%); among selective users, equivocal IHC was the leading trigger (6/8, 75%). Overall, metabolic RCC recognition in Italy is primarily morphology-driven but constrained by uneven access to confirmatory IHC, particularly 2SC, and to molecular assays. The findings argue for harmonized diagnostic algorithms, regional reference laboratory networks, and routine involvement of molecular tumor boards, supported by targeted educational initiatives (including curated digital slide repositories), to standardize practice and improve patient pathways from morphologic suspicion to genetic counselling and tailored surveillance.

HER2-low and -ultralow breast cancer have recently emerged as distinct theranostic subcategories within the HER2 spectrum, prompting reassessment of traditional HER2-negative immunohistochemistry scores (0, 1+ , and 2+ without amplification). This study reclassifies, according to this new categorization, a cohort of 367 patients who have never received chemotherapy and have non-metastatic triple-negative breast cancer (TNBC). We evaluated its association with their clinicopathological features and prognosis. HER2 0 tumors were reclassified as HER2-null (no staining) or HER2-ultralow (≤10% faint, incomplete membrane staining). HER2 1+ or 2+ (non-amplified) tumors were defined as HER2-low. Overall, 38.4%, 37.6% and 24.0% of TNBC samples were reclassified as HER2-null, -ultralow and -low, respectively. HER2-ultralow tumors were more frequently associated with the presence of tertiary lymphoid structures (p = 0.0259) and BRCA1 promoter methylation (p = 0.0439) than HER2-low tumors. Moreover, compared with HER2-null samples, HER2-ultralow tumors were of smaller size (p = 0.0167) and lower stage and grade (p = 0.0066 and p = 0.0364, respectively). Conversely, age, lymph node involvement, histology, molecular apocrine or basal-like phenotypes, PIK3CA and PTEN status, immune infiltrates, assessed using T-cell (CD3), B-cell (CD20) and macrophage (CD163) markers, and PD-L1 expression in tumor or stromal cells were not associated with the HER2-ultralow status. The survival analysis (median follow-up = 10.3 years) showed that relapse-free survival was not influenced by the HER2 status. Despite some significantly different clinicopathological features, there is no solid evidence to support HER2-ultralow, HER2-low and HER2-null cancers as individual TNBC clinical-molecular entities. Particularly, assigning TNBC samples to the HER2-null, -ultralow and -low categories did not bring any additional prognostic value.

The reliable diagnosis of one of the many types of B-cell lymphoma (BCL) currently requires an integrated approach comprising morphological expertise, immunophenotyping, and inclusion of clinical data, but may also incorporate flow cytometry, cytogenetics, and clonality analysis. In recent years, several studies have elucidated the mutational landscape of BCL, which may also serve as a complementary diagnostic tool. We have developed a custom next-generation sequencing panel for application in the routine diagnosis of BCL based on available literature and our diagnostic questions. We applied this panel to 160 cases of BCL or with this differential diagnosis (DD) in our routine workflow to gain further diagnostic support or on clinical request. Evaluable results were obtained in all but two cases of the entire cohort. Diagnostically informative molecular genetic profiles were identified in 72% of the evaluable cases. Focusing on 21 challenging cases with the DD of Burkitt lymphoma (BL) and the germinal center B-cell-like subtype of diffuse large B-cell lymphoma (DLBCL), we detected at least one mutation in all cases, and in 18/21 (86%) cases, panel sequencing provided significant decision guidance. In conclusion, although morphology and immunohistochemistry remain the backbone of diagnosis, panel sequencing provided substantial diagnostic assistance in many cases. It has been particularly useful in providing additional arguments to clarify the clinically important DD between BL and DLBCL in challenging cases.