Background: Epidemiological data on primary cutaneous lymphomas (PCLs) are rare and have not previously been investigated in Switzerland.
Objective: To analyse variations in demographics, the pattern of subtypes and staging during the two 10-year intervals, 1990-1999 and 2000-2009.
Methods: This was a descriptive study of 263 patients with PCL based on a retrospective review and reassessment according to the World Health Organization/European Organization for Research and Treatment of Cancer classification.
Results: Change was observed in the pattern of cutaneous T-cell lymphoma subtypes: the frequency of Sézary syndrome decreased from 17% to 7% and the frequency of CD30+ lymphoproliferative disorders increased from 7% to 18% (overall P = 0·04). Staging of PCL showed a higher number of cases of early-stage mycosis fungoides (P = 0·01). In relation to the international data, the Zürich group had a higher number of patients with Sézary syndrome (11% vs. 3%) and marginal cell lymphoma (14% vs. 5-7%). In addition, comparison of the survival data showed prolonged median overall survival of Zürich patients with Sézary syndrome in the second 10-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.
© 2011 The Authors. BJD © 2011 British Association of Dermatologists.