Some statistical data, diagnosis, and staging of cutaneous B-cell lymphomas.

Cutaneous B-cell lymphomas represent a considerable number of skin lymphomas (about one-third) primarily showing skin manifestation without any extranodal involvement detectable using routine and special staging procedures. Differentiation from cutaneous T-cell lymphomas can be achieved clinically; histologically, due to the distinct growth pattern in the skin; and by immuno- or enzymophenotyping of the proliferating cells. Further differentiation of subtypes of cutaneous B-cell lymphomas is based primarily on cytomorphologic phenotyping of the cells. Classification of B-cell lymphomas with "primary" cutaneous manifestation according to the TNM system discloses a more adequate basis for prognostic and therapeutic considerations than the Ann Arbor classification for nodal lymphomas.