RESUMEN
BACKGROUND: Primary cutaneous B-cell lymphomas (PCBCL), with the exception of large B-cell lymphoma of leg type and intravascular large B-cell lymphoma, are associated with an excellent prognosis. These lymphomas have become much better understood in recent years leading to the publication in 2005 of the World Health Organization-European Organisation for Research and Treatment of Cancer classification. OBJECTIVES: To determine the relative frequency of occurrence of subtypes of PCBCL in a defined population, and the survival of patients with these subtypes. METHODS: During the period 1987-2009, 61 consecutive patients with PCBCL were identified from the Nottingham Lymphoma Registry (population 1·1 million). After histological review, the number of patients with each subtype was as follows: marginal zone, 18; follicle centre, 14; diffuse large B cell, leg type, 16; diffuse large B cell, other sites, 12; and intravascular large B cell, one. RESULTS: The 5- and 10-year lymphoma-specific survival for patients with marginal zone lymphoma was 100%. The only patient with intravascular large B-cell lymphoma died from widespread disease in spite of chemotherapy. The 4-year lymphoma-specific survival for follicle centre cell lymphoma was 90%. Patients with the other subtypes had the following 5-year lymphoma-specific survival rates: diffuse large B cell, leg type, 61% and diffuse large B cell, other, 40%. The median age at diagnosis for patients with diffuse large B-cell lymphoma, leg type was 82 years and as a consequence the 5-year overall survival was only 15%. There was a 3·4-fold increase in the incidence of PCBCL from the period 1987-1997 to the period 1998-2009. CONCLUSIONS: PCBCL is a rare disease (incidence around three per million population per year). It is, in our view, essential that it is diagnosed by a pathologist with an interest in cutaneous lymphoma and that the very different prognosis of the individual subtypes is appreciated by the treating clinician.