Primary cutaneous large B-cell lymphomas.

According to the European Organization for Research and Treatment of Cancer classification, primary cutaneous large B-cell lymphomas are subdivided into 2 groups: follicle center cell large B-cell lymphomas and large B-cell lymphomas of the leg. The first type predominantly affects middle-aged adults with an equal gender distribution and presents with lesions on the head and trunk. Histology shows proliferations of predominantly large cleaved cells. The prognosis is excellent, with a 5-year survival rate >90%. The second group predominantly affects elderly females. Histologically the lesions are composed of centroblasts and/or immunoblasts (large round cells). The prognosis is more unfavorable with a 5-year survival rate of 50%. Intravascular large B-cell lymphoma is still classified as a provisional entity.