title: Pathogenesis, diagnosis, and treatment of composite lymphomas.
abstract: In rare instances, two distinct lymphomas concurrently occur in a patient. Such composite lymphomas can be combinations of two non-Hodgkin lymphomas or a combination of a non-Hodgkin lymphoma and a Hodgkin's lymphoma. Composite lymphomas pose a particular diagnostic challenge, and there are currently no agreed standards for treatment. Combined B-cell non-Hodgkin lymphomas are often clonally unrelated. However, in many composite non-Hodgkin lymphomas and Hodgkin's lymphomas, the tumours are clonally related. In most of these instances, the malignant clones developed separately from a common precursor, usually a germinal centre B cell. This finding suggests a scenario in which the common premalignant precursor had acquired shared transforming events, and the two distinct lymphomas developed from descendants of that precursor after acquiring additional separate transforming events. Findings from molecular studies support this notion. Hence, clonally related composite lymphomas are elegant models to study the multistep transformation process in lymphomagenesis.
authors.affiliation: Institute of Cell Biology (Cancer Research), University of Duisburg-Essen, Faculty of Medicine, Essen, Germany. Electronic address: ralf.kueppers@uk-essen.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Küppers
authors.affiliation: Department of Hematology, University Hospital Essen, Essen, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Dührsen
authors.affiliation: Dr Senckenberg Institute of Pathology, University of Frankfurt, Medical School, Frankfurt, Germany.
authors.forename: Martin-Leo
authors.initials: ML
authors.lastname: Hansmann
mesh_terms: D001707:Biopsy, Needle; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D058617:Composite Lymphoma / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*; D005260:Female; D006689:Hodgkin Disease / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*; D006801:Humans; D007150:Immunohistochemistry; D016393:Lymphoma, B-Cell / Q000175:diagnosis / Q000473:pathology* / Q000628:therapy*; D008297:Male; D011379:Prognosis; D016896:Treatment Outcome