Recent advances in primary cutaneous B-cell lymphomas

In the last decade, there has been considerable debate regarding the classification and terminology of the group of primary cutaneous B-cell lymphomas (CBCLs). With the introduction of the WHO-EORTC classification for cutaneous lymphomas, three main types of CBCLs are recognized: primary cutaneous marginal zone B-cell lymphoma (PCMZL), primary cutaneous follicle centre lymphoma (PCFCL) and primary cutaneous large B-cell lymphoma, leg type (PCLBCL, LT).

Epidemiological studies performed on different patient cohorts showed that the CBCL entities described in the WHO-EORTC classification and the 4th WHO classification of tumours of haematopoietic and lymphoid tissues are reproducible worldwide and are clinically relevant, thereby illustrating the clinical usefulness of the WHO-EORTC classification. Furthermore, collaborative studies between the ISCL and EORTC lymphoma group resulted in recommended staging procedures and consensus treatment recommendations for different CBCL subtypes.

The advances in the classification, staging procedures and treatment of CBCLs have led to a major improvement in clinical care. The progress in CBCL classification enables molecular studies on well defined groups of patients and facilitates comparison of treatment results between different centres. Recent studies found that intralesional/intravenous rituximab has a therapeutic value in PCFCL and PCMZL with widespread cutaneous lesions and suggest that therapies targeting the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) pathway could be helpful in DLBCL, LT.