Clinical aspects and pathology of primary cutaneous B-cell lymphomas.

Primary cutaneous B-cell lymphomas (pCBCL) occur more frequently than generally believed. The most important subtypes are: marginal zone B-cell lymphoma/immunocytoma, follicle center-cell lymphoma and large B-cell lymphoma of the leg. A correct diagnosis can be rendered only in the context of knowledge of the clinical findings. Progress in terms of classification and biology is associated with the application of modern techniques including immunohistology and laser beam microdissection followed by molecular analysis. Future definitions of pCBCL will be based on their molecular abnormalities and their etiology and pathogenesis. Awareness of the special clinical behavior of pCBCL should prevent unnecessarily aggressive treatment.