Publications by authors named "S Laurent-Roussel"
Re-evaluation of the concept of basaloid follicular hamartoma associated with naevoid basal cell carcinoma syndrome: a morphological, immunohistochemical and molecular study.
Pathology
February 2025
Article Synopsis
- - Naevoid basal cell carcinoma syndrome (NBCCS) is a rare genetic condition caused by mutations in the Sonic Hedgehog (SHH) pathway, leading to early development of multiple basal cell carcinomas (BCCs) and related skin tumors like basaloid follicular hamartoma (BFH).
- - A study analyzed 140 skin tumors from NBCCS patients and 140 control BCC tumors to compare their morphological characteristics, finding that BFH was exclusively present in NBCCS patients and had distinct histopathological features.
- - The research indicates that BFH could represent precursors to BCC, as it was identified in up to 24% of the tumors in NBCCS patients, with possible
Article Synopsis
- The study investigates 16 primary cutaneous carcinomas with mutations in genes that activate the Wnt/β-catenin pathway, noting that these tumors lack matrical differentiation, which is typically associated with such mutations.
- The tumors predominantly affected elderly patients, with a median age of 80, and were mainly located on the head, neck, and upper limbs, leading to metastatic cases in some patients.
- Key findings include poor differentiation in tumor structure, distinct immunohistochemical profiles, and recurrent mutations in APC and CTNNB1, indicating that these tumors represent a unique group apart from other established skin tumor types.
Merkel cell carcinoma (MCC) is an aggressive skin cancer for which Merkel cell polyomavirus integration and expression of viral oncogenes small T and Large T have been identified as major oncogenic determinants. Recently, a component of the PRC2 complex, the histone methyltransferase enhancer of zeste homolog 2 (EZH2) that induces H3K27 trimethylation as a repressive mark has been proposed as a potential therapeutic target in MCC. Because divergent results have been reported for the levels of EZH2 and trimethylation of lysine 27 on histone 3, we analyzed these factors in a large MCC cohort to identify the molecular determinants of EZH2 activity in MCC and to establish MCC cell lines' sensitivity to EZH2 inhibitors.
View Article and Find Full Text PDFAims: Recently, YAP1 fusion genes have been demonstrated in eccrine poroma and porocarcinoma, and the diagnostic use of YAP1 immunohistochemistry has been highlighted in this setting. In other organs, loss of YAP1 expression can reflect YAP1 rearrangement or transcriptional repression, notably through RB1 inactivation. In this context, our objective was to re-evaluate the performance of YAP1 immunohistochemistry for the diagnosis of poroma and porocarcinoma.
View Article and Find Full Text PDFVulvar melanoma is a rare tumour, of poorly known pathogenesis, which presents particularities compared to cutaneous melanoma: more frequently achromic and very often multifocal, it is of the lentiginous histological type (MLM), with in half of the cases lentiginous melanocytic hyperplasia at a distance.
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