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

Summary 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.