The skin-associated lymphoid tissue-related B-cell lymphomas

Primary cutaneous B-cell lymphomas (CBCLs) should be clearly separated from non-Hodgkin's B-cell lymphomas with secondary cutaneous involvement and fr om cutaneous B-cell pseudolymphomas. The majority of CBCLs are characterize d by a homogeneous clinical presentation and behavior, with good response t o local radiotherapy, low tendency to extracutaneous spread, and excellent prognosis. According to the European Organization for Research on the Treat ment of Cancer classification of primary cutaneous lymphomas, CBCLs with an indolent behavior are divided into 2 subgroups: follicular center cell lym phoma and immunocytoma/marginal zone lymphoma, due to putative histologic s imilarities with their purported nodal counterparts. In addition, a third s ubgroup with intermediate prognosis (large B-cell lymphoma of the leg) is i dentified. Conversely, the identification of distinct subgroups is disputab le from a strictly histologic, immunophenotypic, and genotypic point of vie w, and has neither correlation with the clinical course nor the prognosis o f the disease. Moreover, the majority of CBCLs show a uniform immunophenoty pe (CD5-, CD10-) and genotype (lack of bcl-1/bcl-2 and c-myc gene rearrange ment) of neoplastic cells. Therefore, we favor the use of the term Skin-Ass ociated Lymphoid Tissue (SALT)-related B-cell lymphomas, due to the close s imilarities between CBCLs and mucosa-associated lymphoid tissue (MALT) lymp homas, and the evidence for an acquired B-cell arm of SALT, Copyright (C) 2 000 by W.B. Saunders Company.