What is new about primary cutaneous B cell lymphomas.

Primary cutaneous B-cell lymphomas (CBCL) are a heterogeneous group of B-cell lymphomas without evidence of extracutaneous disease at the time of diagnosis. The 2022 World Health Organization classification of mature lymphoid neoplasms differentiates the indolent primary cutaneous marginal zone lymphoproliferative disorder, primary cutaneous follicle center lymphoma and Epstein-Barr virus-positive mucocutaneous ulcer, from the more aggressive primary cutaneous diffuse large B-cell lymphoma, leg-type and intravascular large B-cell lymphoma. The new updates in the 2022 classification are based on recent scientific advances in the understanding and characterization of these entities. This article aims to review the main clinical, cellular and molecular features of the five CBCL subsets along with their management and treatment. The exponentially growing evidence for new treatment options for systemic B-cell lymphomas raises expectations for the field of CBCL as well. However, specific prospective high quality research on CBCL is still crucial to further define their management and update international guidelines.