Classification of cutaneous T-cell lymphoma: from Alibert to WHO-EORTC

Cutaneous T-cell lymphomas (CTCLs) represent a heterogeneous group of neoplasms originating from skin-homing T cells that show considerable variation in clinical presentation, histological appearance, immuno-phenotype, and prognosis. This review provides a historic overview of the classification of CTCLs from the first description of a patient with mycosis fungoides in 1806 to the recently published WHO-EORTC classification. Practical guidelines for the usage of the WHO-EORTC classification and relevant features of new or newly defined entities such as subcutaneous panniculitis-like T-cell lymphoma, extranodal NK/T-cell lymphoma, nasal type, primary cutaneous aggressive CD8-positive cytotoxic T-cell lymphoma, and cutaneous gamma/delta T-cell lymphoma are presented. The aim of this review is to contribute to a better communication between dermatologist and pathologist and in this way to a better diagnosis and classification of CTCLs.