Primary cutaneous B-cell lymphoma : narrative review of the literature

Primary Cutaneous B-cell Lymphomas comprehend a group of lymphoproliferative disorders characterized by being monoclonal proliferations of B-cell primarily involving the skin. Despite being recognized as autonomous and distinct clinico-pathologic entities since the late 80s, their classification is still an ongoing matter of debate. At the moment, WHO classification recognizes three disorders: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma and primary cutaneous diffuse large B-cell lymphoma, leg type. Primary cutaneous diffuse large B-cell lymphoma, other has been used to define rare cases which show histologically an infiltrate with diffuse pattern composed by large B-cell, but not fitting with criteria for follicle center lymphoma nor for primary cutaneous diffuse large B-cell lymphoma, leg type. Aim of this review is to briefly describe all recognized and provisional entities included in the primary cutaneous B-cell lymphomas and to discuss recent acquisitions that may influence their future classifications.