Primary B-cell lymphomas of the skin.

Primary B-cell lymphomas of the skin are not as rare as is generally believed. They are defined as malignant B-cell proliferations presenting with cutaneous involvement alone and no evidence of extracutaneous manifestations over a period of at least six months when complete staging has been performed. The major subtypes are follicle center-cell lymphoma of the head and trunk, immunocytoma and large B-cell lymphoma of the leg (EORTC classification 1996). Also of interest is the recently recognized marginal-zone B-cell lymphoma. Primary B-cell lymphomas of the skin differ significantly from nodal lymphomas. Awareness of their special clinical behavior should prevent unnecessarily aggressive treatment.