Proposed treatment algorithm for PTLD after SOT or HSCT. ASCT, autologous stem cell transplant; CR, complete remission; DLI, donor lymphocyte infusion; FU, follow-up; HDT, high-dose therapy; IS, immune suppression; PCNSL, primary CNS lymphoma; R-CHOP, sequential immunochemotherapy with rituximab followed by CHOP; Tx, transplant.