EORTC classification for primary cutaneous lymphomas: the best guide to good clinical management. European Organization for Research and Treatment of Cancer.

In 1997 the Cutaneous Lymphoma Study Group of the European Organization for Research and Treatment of Cancer (EORTC) published a proposal for a classification for the group of primary cutaneous lymphomas (1). The EORTC classification is the first and only classification that is designed exclusively for the group of primary cutaneous lymphomas. It is also the only classification that has been clinically validated for this group of diseases. As illustrated by this special issue, this classification has resulted not only in the discussion of the definition and terminology of some types of cutaneous T-cell lymphoma (CTCL) and cutaneous B-cell lymphoma (CBCL), but also in a discussion of whether organ-based classification schemes (separate from existing hematopathologic classification schemes for non-Hodgkin lymphomas) should be used. This article explains why it was necessary to create a separate classification for the group of primary cutaneous lymphomas. A short introduction on the history of the classification of cutaneous lymphomas is provided. Next, the basic principles of the EORTC classification are presented. Finally, controversies between the EORTC classification versus the REAL classification (2) and the proposed WHO classification (3), which still impede the usage of one common classification system, are discussed.