Primary cutaneous B-cell lymphomas and pseudolymphomas: review of histopathological features

The terminology and classification of lymphoproliferative disorders in the skin remains a source of confusion for clinicians and pathologists. More than 25 types of malignant lymphoid neoplasms may involve the skin. These either arise primarily or represent secondary cutaneous involvement due to the spread of node-based lymphomas, other extracutaneous lymphomas or leukemias. In addition, there is a variety of cutaneous pseudolymphomatous reactions. This article addresses the histopathological features of primary cutaneous B-cell lymphomas and B-cell pseudolymphomas and presents a modern approach to the diagnosis of these lymphoid neoplasms.