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.