Post-transplant lymphoproliferative disorders (PTLD) are a heterogeneous group of diseases that develop as a consequence of immunosuppression in patients who have undergone solid-organ or haemopoietic-stem-cells transplantation. PTLDs include a series of disorders ranging from Epstein-Barr virus (EBV)-driven polyclonal proliferation to disorders indistinguishable from some B-cell lymphomas or, less often, T-cell lymphomas. Although the diagnosis can be suspected by clinical features (ie, lymphadenopathy),...