Primary cutaneous lymphoma: Two-decade comparison in a population of 263 cases from a Swiss tertiary referral centre

Background:  Epidemiologic data on primary cutaneous lymphomas (PCL) are rare and up to now have not been investigated in Switzerland. Objective:  To analyze variations in demographics, pattern of subtypes and staging during the two ten-year intervals: 1990-1999 and 2000-2009. Methods:  Descriptive study of 263 PCL patients based on a retrospective review and reassessment according to the WHO-EORTC classification. Results:  Change was observed in the pattern of cutaneous T-cell lymphoma subtypes: Sezary Syndrome frequency decreased (17-7%); CD30+ lymphoproliferative disorders frequency increased (7-18%; common p=0.04). Staging of PCL showed a higher number of early stage Mycosis fungoides cases (p=0.01). In relation to the international data, Zurich showed a higher number of Sezary Syndrome (11% vs. 3%) and Marginal Cell Lymphoma (14% vs. 5-7%) patients. Additionally, comparison of the survival data showed prolonged median overall survival of Zurich Sezary Syndrome patients in the second ten-year interval (6.5 vs. 2-4 years). Conclusion:  The increasing frequency of marginal cell lymphoma and CD30+ lymphoproliferative disorders might depend on an increased awareness of these diseases in the medical community driven by progress in the classification and staging of these disease entities.