Primary cutaneous B-cell lymphomas: recent advances in diagnosis and management.

BACKGROUND Primary cutaneous B-cell lymphoma (PCBCL) is a heterogeneous group of rare clonal B-cell lymphoproliferative disorders with distinct clinicopathologic features from more common nodal B-cell lymphomas. METHODS We performed a systematic review of the relevant literature in the MEDLINE database and analyzed laboratory and clinical data. This review discusses the three most common types of PCBCL: primary cutaneous marginal zone lymphoma (PCMZL), primary cutaneous follicle-center lymphoma (PCFCL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT). RESULTS Skin biopsies with histology, immunohistochemistry, and molecular clonality studies are essential for a correct diagnosis of cutaneous B-cell lymphoma. Comprehensive lymphoma staging with laboratory and imaging studies and bone marrow aspiration and biopsy are important for determining the prognosis and differentiation of PCBCL from secondary skin involvement with systemic B-cell lymphomas. PCMZL and PCFCL are low-grade PCBCLs, with an estimated 5-year disease-specific survival rate of greater than 95%. Surgical excision or focal radiation therapy is sufficient to control stages T1 and T2 disease. Rituximab monotherapy is frequently used for patients with stage T3 disease. PCDLBCL, LT is an intermediate-grade B-cell lymphoma, with a 5-year disease-specific survival rate of approximately 50%. An anthracycline-based chemotherapy regimen with rituximab is usually required as initial therapy to improve outcomes. CONCLUSIONS In less than a decade, significant progress has been made in our understanding of PCBCL. Novel classification, staging, and prognostic systems have resulted in more accurate diagnosis and prognosis. Although no randomized prospective studies have been conducted in PCBCL, therapies derived from systemic B-cell lymphomas have shown promising results.