Discordant bone marrow involvement in diffuse large-cell lymphoma: A distinct clinical-pathologic entity associated with a continuous risk of relapse

From 1975 to 1988, 50 patients with lymph node biopsy-documented diffuse large-cell lymphoma (DLCL) presented with bone marrow involvement. Twenty-four patients (48%) had large-cell lymphoma (LCL) in the bone marrow and were compared with 19 (38%) patients who had small cleaved-cell lymphoma (SCCL) in the marrow. Additionally, seven patients (14%) had mixed small- and large-cell lymphoma (ML) in the marrow. Patients who had LCL marrow involvement were younger (P < .02) and more frequently had elevated lactic dehydrogenase (LDH) levels (P < .001), high tumor burden (P < .01), and more sites of extranodal disease (P < .05) than those with SCCL in the marrow. The complete response (CR) rate to multiagent chemotherapy was 16.7% in the LCL group and 89.4% in the SCCL group (P < .001). One third of the patients with LCL in the marrow developed CNS involvement, compared with only one patient in the SCCL group (P = .06). Overall 5-year survival was 79% in patients with SCCL marrow involvement, compared with only 12% in patients with LCL in the marrow (P = .002). Despite a high CR rate, patients with marrow involved by SCCL were at a high continuous risk of relapse with only a 30% failure-free survival at 5 years. We conclude that bone marrow involvement with LCL predicts for extremely poor prognosis with low response rate and short survival. Patients with SCCL in the bone marrow have a high rate of CR and a high rate of 5-year survival; however, there is a high risk of late relapse, and only 15% are in a continuous remission at 8 years.