AJHE2304 - CME/CMLE - B-cell lineage neoplasms transdifferentiating into histiocytic/dendritic cell neoplasms: diversity, differentiation lineage, genomic alterations, and therapy Report from the 2021 SH/EAHP Workshop-B-cell lineage neoplasms transdifferentiating into histiocytic/dendritic cell neoplasms: diversity, differentiation lineage, genomic alterations, and therapy Report from the 2021 SH/EAHP Workshop

B-cell lineage neoplasms transdifferentiating into histiocytic/dendritic cell neoplasms: diversity, differentiation lineage, genomic alterations, and therapy Report from the 2021 SH/EAHP Workshop

Back to course

Pdf Summary

The review article delves into the transdifferentiation of B-cell lineage neoplasms into histiocytic/dendritic cell neoplasms (HDCNs), highlighting the heterogeneity and diagnostic difficulties associated with HDCNs. The workshop analyzed 29 cases, with histiocytic sarcoma being the most common HDCN followed by Langerhans cell histiocytosis/sarcoma. Genetic alterations in the MAPK pathway were identified as therapeutic targets, with overlapping immunophenotypic features observed in cases. The study proposed an algorithm for HDCN lineage assignment based on specific markers. Diagnostic challenges, differentiation from B-cell lymphomas, and proposed guidelines for improved cell lineage assignment were discussed. Activation of the MAPK pathway, mutations in genes like MAP2K1 and BRAF, clonal relatedness, mutational profiles, and clonal evolution in HDCNs were highlighted. Treatment options targeting the MAPK pathway showed promising responses. The article underlines the importance of accurate classification and molecular characterization of HDCNs for optimal therapeutic outcomes and suggests exploring RNA sequencing for lineage designation. The document emphasizes ongoing efforts in understanding HDCNs' heterogeneity for precise classification, effective therapy, and potential immunotherapy targets in the future.

Keywords

transdifferentiation

B-cell lineage neoplasms

histiocytic/dendritic cell neoplasms

HDCNs

diagnostic difficulties

genetic alterations

MAPK pathway

immunophenotypic features

lineage assignment

therapeutic targets