Neoplastic nodular B-cell pattern
Cutaneous B-cell lymphomas encompass a group of B-cell lymphomas that presents in the skin without evidence of extra-cutaneous disease at the time of initial diagnosis; thus, complete laboratory workup and imaging studies are necessary. In 2005 a new consensus classification for cutaneous lymphoma was introduced by the World Health Organization (WHO) and the European Organization for Research and Treatment of Cancer (EORTC). This classification has resulted in a significant improvement on categorization of cutaneous B-cell lymphoma and unified criteria for therapeutic trials. This chapter focuses on primary cutaneous follicle center lymphoma; primary cutaneous marginal zone B-cell lymphoma; cutaneous plasmacytoma; primary cutaneous large B-cell lymphoma, leg type; and other primary cutaneous large B-cell lymphomas including plasmablastic lymphoma and primary cutaneous T-cell/histiocyte-rich B-cell lymphoma.