Intralesional rituximab treatment for primary cutaneous B-cell lymphoma: Nine finnish cases

Abstract

Primary cutaneous B-cell lymphomas (PCBCL) are rare skin-defined non-Hodgkin lymphomas with no extracutaneous involvement at the time of diagnosis. They are classified into 3 major entities in the 2008 WHO-EORTC joint classification (1). These 3 most common types include primary cutaneous follicle centre lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL) and primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL-LT). PCBCL constitute approximately 25% of all skin lymphomas. It is important to distinguish between PCBCL and systemic B-cell lymphomas with skin involvement, since most PCBCL are low-grade malignancies with a 5-year survival of up to 95-99% (2). The current treatment options for PCBCL (besides local treatments, e.g. topical corticosteroids, nitrogen mustard, bexarotene) include radiotherapy, surgical excision, chemotherapy, interferon-α and monoclonal antibodies (3-5). For aggressive forms, polychemotherapy is used. Rituximab is a chimeric monoclonal immunoglobulin G antibody targeting CD20, which is expressed on normal and tumour B cells (6). Intravenous rituximab is commonly used in systemic low-grade B-cell non-Hodgkin lymphomas (7), whereas intralesional rituximab is being increasingly used as an alternative to conventional treatments (radiation or surgery) (5). No randomized studies are available on the efficacy of intralesional rituximab treatment, but there are some reports of the effect of intralesional rituximab in PCBL (8-15).