Characteristics of cutaneous lymphomas in Korea according to the new WHO-EORTC classification: Report of a nationwide study

Background: Previously, cutaneous lymphomas were classified according to either the European Organization for the Research and Treatment of Cancer (EORTC) or the World Health Organization (WHO) classification paradigms. The aim of this study was to determine the relative frequency of Korean cutaneous lymphoma according to the new WHO-EORTC classification system. Methods: A total of 517 patients were recruited during a recent 5 year-period (2006-2010) from 21 institutes and classified according to the WHO-EORTC criteria. Results: The patients included 298 males and 219 females, and the mean age at diagnosis was 49 years. The lesions preferentially affected the trunk area (40.2%). The most frequent subtypes in order of decreasing prevalence were mycosis fungoides (22.2%), peripheral T-cell lymphoma (17.2%), CD30+ T-cell lymphoproliferative disorder (13.7%), and extranodal natural killer/T (NK/T) cell lymphoma, nasal type (12.0%). Diffuse large B-cell lymphoma accounted for 11.2% of cases, half of which were secondary cutaneous involvement; other types of B-cell lymphoma accounted for less than 1% of cases. Conclusions: In comparison with data from Western countries, this study revealed relatively lower rates of mycosis fungoides and B-cell lymphoma in Korean patients, as well as higher rates of subcutaneous panniculitis-like T-cell lymphoma and NK/T cell lymphoma.