ABSTRACT
Cutaneous lymphomas include B- and T-cell lymphoma, both primary and systemic. T-cell lymphomas comprise the majority of primary cutaneous lymphomas. Cutaneous B-cell lymphomas are much less common than primary cutaneous T-cell lymphomas and constitute 20%–30% of all primary cutaneous lymphomas. Primary cutaneous B-cell lymphomas are defined as B-cell lymphoproliferative disorders originating in the skin with no evidence of extracutaneous disease at presentation for at least 6 months after diagnosis. Primary cutaneous marginal zone lymphoma (MZL) occurs most often in the third to fifth decade of life and in the majority of patient's presents with multifocal red nodules, most often on arms and trunk. Cutaneous MZLs frequently show plasmacytic differentiation, similar to MZL in the thyroid and other extranodal sites. Primary cutaneous MZL is an indolent lymphoma composed of small B cells, including marginal zone cells or monocytoid cells, lymphoplasmacytoid cells, and plasma cells.
