Herein we describe 7 cases of posttransplantation lymphoproliferative disease (PTLD), 5 in men and 2 in women (aged from 25 to 62 years), occurring from 4 months to 12 years (mean, 7 years) after transplantation. Our patients were recipients of kidney, kidney and pancreas, heart, and autologous peripheral haematopoetic stem cells. Four cases were diagnosed as monomorphic and three as polymorphic type of PTLD according to the WHO classification. Monoclonal immunoglo- buline heavy chain gene rearrangement was detected in two monomorphic lesions and one polymorphic lesion by polymerase chain reaction (PCR). In the two cases of polymorphic and the one case of monomorphic PTLD, the presence of EBV was visualised by immunohistochemical staining of some transformed lymphoid cells for latent membrane protein (LMP) of EBV. The presence of type A EBV was demonstrated by PCR. The patients were treated by reduction or discontinuation of immunosuppression and by chemotherapy. In 2 cases, a part of the organ affected by lymphoma (sigmoid colon and pancreas) was surgically resected. Four patients died of causes related to PTLD (2 to 15 months after the diagnosis), mainly of infectious complications. Two other patients who achieved remission died of unrelated causes. Only the youngest man is alive and in the complete remission 10 months after the diagnosis of PTLD.

        Key words: lymphoproliferative disorder - transplantation - immunosuppression - Epstein-Barr virus