The absence of FOXA2 and HNF1β expression in vasculogenic mesenchymal lesions of germ cell origin suggests an evolutionary pathway similar to that of sarcomatoid yolk sac tumor.

Vasculogenic mesenchymal lesions (VMLs) are uncommon phenotypes of germ cell tumor (GCT) origin that are mostly found after chemotherapy of mediastinal yolk sac tumor (YST). These lesions typically lack expression of classical YST markers [α-fetoprotein (AFP) and glypican-3 (GPC3)]. FOXA2 and HNF1β are key inducers of the YST phenotype and co-operate to promote transcription of genes involved in YST development (AFP, GPC3, GATA3, among others).

Computer-Based Detection of Colorectal Serrated Lesions: Digital Flatness, a Novel Metric Designed for Whole-Slide Images.

Colorectal sessile serrated lesions (SSLs) and hyperplastic polyps (HPs) are characterized by sawtooth or stellate epithelial architecture. Distinguishing between SSLs and HPs is crucial as SSLs are precursors of colorectal carcinomas in 30% of cases, whereas HPs are likely precursors to SSLs. The differentiation of SSL from HP is primarily based on architectural features.

Unveiling the molecular landscape and clinically relevant molecular heterogeneity of mucosal melanoma of the head and neck region.

Aims: Mucosal melanoma of the head and neck (MM-H&N) is an aggressive disease known for its frequent residual tumours/relapses (RT/R) at the surgical site, as well as eventual metastases. Our understanding of the MM-H&N mutational landscape, together with the correlation of specific mutations with clinical-pathological features, is significantly less comprehensive compared to that of cutaneous melanoma. Additionally, the mutational status of consecutive samples collected from single patients has not been investigated, which limits our ability to characterise the prognosis and treatment options for this patient subset.

Analysis of HNF1β expression suggests that its downregulation is involved in the sarcomatoid transformation of yolk sac tumor.

Sarcomatoid yolk sac tumor postpubertal-type (YSTpt) is a rare phenotype of germ cell tumor that occurs mostly after chemotherapy. Its diagnosis is clinically relevant but challenging, due to its somewhat inconspicuous histologic features and negative/low expression of classical YSTpt makers (α-fetoprotein (AFP), glypican-3 (GPC3), and GATA3)). HNF1β is likely a key inducer of the YSTpt phenotype, acting in part by regulating the binding of FOXA2 to its target genomic sequences.

A reproducibility study on invasion in small pulmonary adenocarcinoma according to the WHO and a modified classification, supported by biomarkers.

Objectives: Evaluating invasion in non-mucinous adenocarcinoma (NMA) of the lung is crucial for accurate pT-staging. This study compares the World Health Organization (WHO) with a recently modified NMA classification.

Materials And Methods: A retrospective case-control study was conducted on small NMA pT1N0M0 cases with a 5-year follow-up.

The positive impact of virtual microscopy on histopathology education: a comparative, student-centered study.

Because of the recent pandemic, new teaching methods have been trialed, even in traditional disciplines such as histopathology that typically involve extensive hands-on laboratory work. In this study, we investigated the effects of three different learning modalities in histopathology teaching: optical microscopy, in-class virtual microscopy (VM), and online VM lectures. We examined relational aspects, didactic effectiveness, and satisfaction in these learning settings, both during class time and in private study, outside the dedicated spaces and hours of the university.

Immunophenotypic Profile of Adult Glioblastoma IDH-Wildtype Microenvironment: A Cohort Study.

: Glioblastoma -wildtype (GBM -wt) is the most aggressive brain tumor in adults and is characterized by an immunosuppressive microenvironment. Different factors shaping its tumor microenvironment (TME) regulate tumor progression and treatment response. The aim of this study was to characterize the main immunosuppressive elements of the GBM -wt TME.

Stereologic consequences of iatrogenic collapse: The morphology of adenocarcinoma in situ overlaps with invasive patterns. Proposal for a necessary modified classification of pulmonary adenocarcinomas.

Recognizing non-invasive growth patterns is necessary for correct diagnosis, invasive size determination and pT-stage in resected non-small cell lung carcinoma. Due to iatrogenic collapse after resection, the distinction between adenocarcinoma in-situ (AIS) and invasive adenocarcinoma may be difficult. The aim of this study is to investigate the complex morphology of non-mucinous non-invasive patterns of AIS in resection specimen with iatrogenic collapse, and to relate this to follow-up.

Pathological T3 Non-Small Cell Lung Cancer with satellite nodules: Number or size, what does matter?

Background: Non-small Cell Lung Cancer (NSCLC) with intralobar satellite nodule are defined as T3 (T3SN). We investigated the main features of these tumors and analyzed their impact on Overall Survival (OS).

Methods: This was a retrospective multicentric study including all pT3SN NSCLC operated on between 2005 and 2020, excluding patients with multifocal ground-glass opacities; who received induction therapies; N3 or stage IV.

Management of post-mortem examination in SARS-CoV-19 infections.

A brief overview on the management of autopsies during the SARS-CoV-19 epidemic is proposed. In particular, the point is made of the Italian laws on the subject, the characteristics required for the autopsy room and the sampling suggested for the histological examination.

Evaluation of an institutional series of low-grade oncocytic tumor (LOT) of the kidney and review of the mutational landscape of LOT.

The 2022 WHO classification of urinary and male genital tumors introduced several novel kidney entities exhibiting eosinophilic/oncocytic features with specific mutational backgrounds. Thus, molecular techniques, such as next-generation sequencing (NGS), became more commonly used for their evaluation. We studied 12 low-grade oncocytic tumors (LOT) of the kidney (from 11 patients), identified in a cohort of 210 eosinophilic/oncocytic renal tumors, diagnosed in our institution between October 2019 and May 2023, which represented 5.

FoxA2 is a reliable marker for the diagnosis of yolk sac tumour postpubertal-type.

Aims: Yolk sac tumour postpubertal-type (YSTpt) shows a wide range of histological patterns and is challenging to diagnose. Recently, forkhead box transcription factor A2 (FoxA2) emerged as a driver of YSTpt formation and a promising marker for diagnosing YSTpt. However, FoxA2 has not been tested in the different patterns of YSTpt.

TAMs PD-L1(+) in the reprogramming of germ cell tumors of the testis.

Background: In recent years, several studies focused on the process of reprogramming of seminoma (S) cells, which regulates the transition from pure S (P-S) to S component (S-C) of mixed germ cell tumors of the testis (GCTT) and finally to embryonal carcinoma (EC) and other nonseminomatous GCTT (NS-GCTT). The accepted pathogenetic model is driven and regulated by cells (macrophages, B- and T-lymphocytes) and molecules of the tumor microenvironment (TME). Herein, we tested a series of GCTT with double staining (DS) for CD68-PD-L1 to evaluate tumor-associated macrophages (TAMs) expressing programmed death-ligand 1 (PD-L1) [TAMs PD-L1(+)] and clarify if these cells may be involved in establishing the fate of GCTT.

PRAME Expression in Mucosal Melanoma of the Head and Neck Region.

PRAME (PReferentially expressed Antigen in MElanoma), a cancer-testis antigen expressed in normal and neoplastic tissues with several functions, proved to be a useful diagnostic tool in the differential diagnosis between benign and malignant melanocytic lesions. The current study aims to perform PRAME stain on a retrospective case series of mucosal melanocytic tumors of the head and neck region to compare 3 different scores and evaluate the most reliable one in this diagnostic set. Immunohistochemical analysis for PRAME was performed in 54 benign and malignant mucosal melanocytic tumors of the head and neck region collected from 41 patients.

Carotid free-floating thrombus in COVID-19: a cerebrovascular disorder of cytokine storm-related immunothrombosis.

Backgrounds: Several neurological manifestations, including stroke, have been reported in COVID-19 patients. The putative role of the COVID-19-related hyperinflammatory state in cerebrovascular disorders remains unclear.

Methods: From March 2020 to September 2021, we searched for patients who exhibited an ischemic stroke related to carotid free-floating thrombus (CFFT) to investigate its incidence and relationship with COVID-19.

H&E and OCT4/CD34 for the assessment of lympho-vascular invasion in seminoma and embryonal carcinoma.

Background: Lymphovascular invasion (LVI) is a relevant prognostic factor in germ cell tumors of the testis (GCTT), and it is included in the pT stage. However, its detection on hematoxylin and eosin (H&E) slides is very challenging, and previous studies reported fair to moderate inter-observer agreement among dedicated uropathologists. In the present study, we tested H&E and a recently developed in-house double staining for OCT4/CD34 to detect LVI in GCTT.

Yolk sac tumor of postpubertal-type does not exhibit immunohistochemical loss of SMARCB1/INI1 and SMARCA4/BRG1…but choriocarcinoma?

The recently described SWI/SNF complex-deficient sinonasal carcinoma (SMARCB1 & SMARCA4) may exhibit a yolk sac-like morphology. Tumors with similar features (yolk sac-like histology combined with the immunohistochemical loss of SMARCB1/INI1 and/or SMARCA4/BRG1) have also been described in other sites, such as the female genital tract. In this study, we immunohistochemically assessed SMARCB1/INI1 and SMARCA4/BRG1 expression to evaluate if these proteins could be involved in the pathogenesis of testicular yolk sac tumors of postpubertal type (YSTpt).