ModPath Chat

This episode is a conversation with Professor Anne Vincent-Salomon from Institut Curie, Paris and
Dr. Maxim De Schepper from University Hospitals Leuven, Belgium. The topic is the European Lobular Breast Cancer
Consortium study aiming to harmonize the pathological diagnosis of ILC by comparing 5 commonly used E-cadherin
antibody clones (NCH-38, EP700Y, Clone 36, NCL-L-E-cad [Clone 36B5], and ECH-6). Based on the study findings,
the guests describe the indication for E-cadherin staining, choice of antibodies, and IHC interpretation to
standardize ILC diagnosis in current pathology practice

Drs. Guido Martignoni and Anna Caliò from the University of Verona in Italy discuss their recent study on primary and metastatic fumarate hydratase (FH)-deficient renal cell carcinomas. Six metastatic tumors were histologically documented with high frequency of involvement of lymph nodes, liver and peritoneal cavity. Metastases were morphologically heterogeneous often differing from corresponding primary. Interestingly, some peritoneal metastases morphologically resembled a benign reactive mesothelial process or primary peritoneal mesothelioma, a pitfall that can be avoided by performing IHC panels that include PAX8 and FH. As for therapeutic predictors, significant PD-L1 labeling was found in 60% of primary renal tumors, whereas none of them carried pathogenetic EGFR mutations.

Dr. Claudio Luchini from the University of Verona and Dr. Gaetano Paolini from Brescia University Hospital in Italy discuss their systematic review article, published in Modern Pathology, on Intraductal oncocytic papillary neoplasm (IOPN) of the pancreas.

Our host discusses with Drs. Shaomin Hu from Cleveland Clinic and Yue Xue MD PhD, from Case Western
Reserve in Cleveland Ohio, their multi-institutional study on gastrointestinal (GI) tract involvement by Langerhans
cell histiocytosis (LCH). The authors highlight new insights from their large study showing that adult patients with
multisystem LCH exhibit similar clinicopathologic features to those of pediatric patients. Adults with single-system
LCH involving the GI tract have an excellent prognosis, whereas multisystem LCH occurring at any age carries an
unfavorable prognosis. High-risk features of GI LCH include pediatric age, GI symptomatology, noncolorectal GI
involvement, multifocal GI disease, nonpolypoid lesions, and infiltrative growth pattern.

Our host discusses with Dr. Anna Laury, from the Department of Pathology, University of Helsinki, Finland, her team's study on the utilization of AI-guided spatial transcriptomic analysis to allow for the biological interpretation of morphologic features detected by AI algorithms when applied to WSI of standard H&E sections.

The authors previously trained an AI model to identify HGSC (high-grade serous carcinoma of the ovary) tumor regions that are highly associated with outcome status but are indistinguishable by conventional morphologic methods. In the here discussed study, Dr. Laury’s team applied spatially resolved transcriptomics to further profile the AI-identified tumor regions in 16 patients (8 per outcome group) and identify molecular features related to disease outcome in patients who underwent primary debulking surgery and platinum-based chemotherapy.