PRIMARY CUTANEOUS LARGE B-CELL LYMPHOMAS OF THE LEGS - A DISTINCT TYPE OF CUTANEOUS B-CELL LYMPHOMA WITH AN INTERMEDIATE PROGNOSIS

Background and Design: Primary cutaneous follicular center cell lympho mas represent a distinct type of cutaneous B-cell lymphoma, clinically characterized by localized skin lesions on the head or trunk and an e xcellent prognosis. Histologically similar lymphomas may occur on the legs. The clinical behavior of this group is still undefined, and cont roversy exists whether these lymphomas should be classified as follicu lar center cell lymphoma or B-immunoblastic lymphoma. We reviewed the clinical, histologic, and follow-up data of 18 patients with primary c utaneous large B-cell lymphoma of the legs. Results: Primary cutaneous large B-cell lymphoma of the legs generally occurred in elderly patie nts (median age at diagnosis, 76 years), in particular women (male-fem ale ratio, 7:2), and preferentially affected the lower legs (14 of 18 patients). Radiotherapy and/or systemic polychemotherapy resulted in c omplete remissions in 16 of 17 patients. Follow-up data demonstrated e stimated 2- and 5-year survival rates of 77% and 58%, respectively, Hi stologic evaluation showed diffuse dermal infiltrates with variable pr oportions of centroblasts (large noncleaved cells), large centrocytes (large cleaved cells), and B immunoblasts. Seventeen of 18 patients we re diagnosed as having primary cutaneous follicular center cell lympho ma; only 1 patient, whose histologic examination showed more than 30% immunoblasts, was diagnosed as having B-immunoblastic lymphoma. Conclu sions: Primary cutaneous large B-cell lymphoma of the legs is a distin ct clinicopathologic entity that mainly affects elderly patients and h as an intermediate prognosis. Although most cases have a follicular ce nter cell origin, primary cutaneous large B-cell lymphoma is proposed as the most appropriate term for this type of cutaneous lymphoma.