Primary Cutaneous B-Cell Lymphomas
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.
Primary cutaneous B-cell lymphoma (PCBCL) belongs to a group of rare B-cell lymphoproliferative disorders that present in the skin and have no evidence of extracutaneous manifestation at the time of initial diagnosis. Clinicopathologic features of PCBCL are distinct from those of its nodal counterparts. Recently, several advances in the classification, diagnosis, and prognosis of PCBCL have been made.
In 2005, the World Health Organization (WHO) and the European Organization for Research and Treatment of Cancer (EORTC) introduced a new consensus classification for cutaneous lymphoma, which reconciled previous disagreements between these two classification systems. The WHO classification of lymphomas published in 2001 defined PCBCL disease entities based only on histology and molecular parameters, whereas the EORTC classification included both histology and skin site.
Three major disease entities of PCBCL have been recognized in this new joint classification system: primary cutaneous marginal zone lymphoma (PCMZL), primary cutaneous follicle-center lymphoma (PCFCL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT).
The Ann Arbor staging system used for staging of systemic non-Hodgkin lymphoma (NHL) has only limited prognostic value in PCBCL as patients are classified in only two stages: IE and IVE. The International Society for Cutaneous Lymphoma and the Cutaneous Task Force of EORTC (ISCL/EORTC) developed a proposal of a new TNM classification for primary cutaneous lymphomas other than mycosis fungoides and Sézary syndrome. This system is based on the number, size, and area of distribution of tumor lesions (Table 1). Although several retrospective studies investigated a validity of new classification and staging systems on independent cohorts of patients, no larger prospective study for patients with PCBCL has been conducted to validate these systems in clinical practice.
Two prognostic systems also have been proposed for PCBCL. The National Comprehensive Cancer Network (NCCN) guidelines for NHL recognized differences in the diagnosis and management of PCBCL and created separate recommendations for this group of B-cell malignancies. Herein, we discuss the clinical and pathological characteristics of the most common entities in the group of PCBCL.
Abstract and Introduction
Abstract
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.
Introduction
Primary cutaneous B-cell lymphoma (PCBCL) belongs to a group of rare B-cell lymphoproliferative disorders that present in the skin and have no evidence of extracutaneous manifestation at the time of initial diagnosis. Clinicopathologic features of PCBCL are distinct from those of its nodal counterparts. Recently, several advances in the classification, diagnosis, and prognosis of PCBCL have been made.
In 2005, the World Health Organization (WHO) and the European Organization for Research and Treatment of Cancer (EORTC) introduced a new consensus classification for cutaneous lymphoma, which reconciled previous disagreements between these two classification systems. The WHO classification of lymphomas published in 2001 defined PCBCL disease entities based only on histology and molecular parameters, whereas the EORTC classification included both histology and skin site.
Three major disease entities of PCBCL have been recognized in this new joint classification system: primary cutaneous marginal zone lymphoma (PCMZL), primary cutaneous follicle-center lymphoma (PCFCL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT).
The Ann Arbor staging system used for staging of systemic non-Hodgkin lymphoma (NHL) has only limited prognostic value in PCBCL as patients are classified in only two stages: IE and IVE. The International Society for Cutaneous Lymphoma and the Cutaneous Task Force of EORTC (ISCL/EORTC) developed a proposal of a new TNM classification for primary cutaneous lymphomas other than mycosis fungoides and Sézary syndrome. This system is based on the number, size, and area of distribution of tumor lesions (Table 1). Although several retrospective studies investigated a validity of new classification and staging systems on independent cohorts of patients, no larger prospective study for patients with PCBCL has been conducted to validate these systems in clinical practice.
Two prognostic systems also have been proposed for PCBCL. The National Comprehensive Cancer Network (NCCN) guidelines for NHL recognized differences in the diagnosis and management of PCBCL and created separate recommendations for this group of B-cell malignancies. Herein, we discuss the clinical and pathological characteristics of the most common entities in the group of PCBCL.