title: [The spectrum of lymphoproliferations and malignant lymphoma after organ transplant].
abstract: Lymphoproliferative disease in patients with organ transplantation has increasingly been diagnosed in recent years. It is caused by immunosuppression after organ transplantion. A large percentage of these tumors is associated with Epstein-Barr virus infection. The classification differentiates between early lesions, polymorphic and monomorphic lymphoproliferations. Whereas the early lesions are often polyclonal, the remaining groups are mostly monoclonal. Polymorphic lymphoproliferative disease shows a wide spectrum of B-cell differentiation, whereas monomorphic proliferations resemble sproadic malignant lymphomas. The latter also show genetic abberations of the c-myc-, Ras-, p53- and Bcl6-genes. With reference to the germinal center reaction, posttransplant lymphoproliferations have to be assigned to the post-follicular activated B-cell type. While until 1991 only 2% of the cases of PTLD had an EBV-association, the EBV-associated PTLD have been frequently observed in recent times and presently constitute about 20% of the cases. EBV-negative PTLD constitute a negative prognostic factor. Posttransplant lymphomas might also represent a model for sporadic lymphoproliferative disease, that for example also occurs at elderly patients.
authors.affiliation: Institut für Pathologie, Universität Würzburg.
authors.forename: H K
authors.initials: HK
authors.lastname: Müller-Hermelink
authors.forename: G
authors.initials: G
authors.lastname: Ott
authors.forename: B
authors.initials: B
authors.lastname: Kneitz
authors.forename: T
authors.initials: T
authors.lastname: Rüdiger
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology / Q000473:pathology; D020031:Epstein-Barr Virus Infections / Q000473:pathology; D006801:Humans; D008223:Lymphoma / Q000235:genetics / Q000473:pathology*; D008232:Lymphoproliferative Disorders / Q000473:pathology*; D016377:Organ Transplantation / Q000473:pathology*; D011183:Postoperative Complications / Q000145:classification / Q000473:pathology*; D011379:Prognosis