Histological transformation to diffuse large B-cell lymphoma is a rare complication which may occur in Waldenstrom macroglobulinemia. In this multicenter study, we retrospectively analyzed the clinico-biological features, therapy, outcomes and prognostic factors in 77 Waldenstrom macroglobulinemia (WM) patients with biopsy-proven transformation to diffuse large B-cell lymphoma (DLBCL).~We retrospectively searched the databases of French and Belgian centers for patients older than 18 years diagnosed with WM and a concurrent or sequential diagnosis of DLBCL between 1995 and 2016. Nineteen centers belonging to the French Innovative Leukemia Organization (FILO) group participated in this study. Patients with a diagnosis of indolent lymphoma other than WM were excluded. The diagnosis of WM was based on criteria established in the Second International Workshop on WM. Clinical, biological data and prognostic scores were recorded. Quantitative variables were expressed as median and range and qualitative variables as number and percentages. Multivariate analyses using cox proportional hazard model were conducted to investigate the factors independently related to progression-free survival and overall survival.
Histological transformation to diffuse large B-cell lymphoma is a rare complication which may occur in Waldenstrom macroglobulinemia. In this multicenter study, we retrospectively analyzed the clinico-biological features, therapy, outcomes and prognostic factors in 77 Waldenstrom macroglobulinemia patients with biopsy-proven transformation to diffuse large B-cell lymphoma.