A Study to Evaluate the Relationship of Lenalidomide With Tumor Flare Reaction and High Tumor Burden in Participants With Relapsed or Refractory Mantle Cell Lymphoma

This is a European multinational, retrospective, non-interventional study of participants with relapsed or refractory mantle cell lymphoma (R/R MCL). Potential sites will be identified where R/R MCL participants have been treated with lenalidomide. Site inclusion will be limited to countries where lenalidomide is reimbursed for this indication.