Clinical study of primary cutaneous B-cell lymphoma using both the European Organization for Research and Treatment of Cancer and World Health Organization classifications.

Primary cutaneous B-cell lymphoma (PCBCL) is rare, with few series reported in the literature. Its classification and treatment remain controversial. Biopsy specimens of 13 patients with PCBCL were classified according to both the European Organization for Research and Treatment of Cancer (EORTC) and the new World Health Organization (WHO) classifications. Treatment and clinical outcomes were documented. Using the EORTC classification there were seven men and six women aged 32-85 years (mean = 51 years) with follicle centre cell (FCC) lymphoma (nine), immunocytoma (two) and primary cutaneous large B-cell lymphoma of the leg (PCLBCL-leg) (two). When the WHO classification was used, the nine patients with FCC were reclassified as follicle centre (five) and diffuse large B-cell lymphoma (four). Most patients had localized disease (12). Initial treatment consisted of radiotherapy alone (seven), combination chemotherapy alone (one), combined chemoradiotherapy (three) and surgery (two). Twelve patients achieved complete remission (median follow up 28 months, range 10-167 months). One patient with PCLBCL-leg died from progressive cutaneous disease. Most localized PCBCL lesions (except PCLBCL-leg) have a favourable prognosis. We recommend that clinicians be familiar with the important differences in the EORTC and WHO classifications. Further large prospective studies comparing the WHO and EORTC classifications are required to more clearly delineate the outcomes of the increasing number of patients who are classified as DLBCL by the WHO system.