Hallermann, ChristianChristianHallermannKaune, Matthias KjellMatthias KjellKauneTiemann, MarkusMarkusTiemannKunze, EkkehardEkkehardKunzeGriesinger, FrankFrankGriesingerMitteldorf, ChristinaChristinaMitteldorfBertsch, Hans-PeterHans-PeterBertschNeumann, ChristineChristineNeumann2018-11-072018-11-072007https://resolver.sub.uni-goettingen.de/purl?gro-2/51009In patients suffering from primary cutaneous lymphomas, secondary malignancies of various origin may develop. However, the frequency of a second neoplasm deriving from another lymphoid lineage is still unclear and may be underestimated. We screened all our patients with primary cutaneous lymphomas from a 4-year recruitment period for a coexisting secondary lymphoproliferative disorder. The cohort comprised of a total of 82 patients with primary cutaneous lymphomas, 62 with primary cutaneous T-cell lymphoma (CTCL), 18 with primary cutaneous B-cell lymphomas, and two with CD4+/CD56+ hematodermic neoplasm/blastic lymphomas. Seven patients (8.5%) were identified with a coexisting lymphoma of a different lymphoid lineage. Four patients with Sezary syndrome (SS) suffered from systemic B-cell lymphoma. Two of these developed SS after chemotherapy of their B-cell lymphoma. The other three patients with various types of skin lymphomas (SS, Mycosis fungoides [MF], primary cutaneous marginal zone lymphoma) developed Hodgkin's disease (hairy cell leukemia). Our data indicate that patients with primary cutaneous lymphomas have an elevated risk for the development of a secondary lymphoproliferative disorder even without previous chemotherapy. Possible explanations for this association include a genetic predisposition, alterations in early progenitor cells, underlying viral infections, and/or stimulation of a B-cell clone by the malignant helper T cells of the primary CTCL and vice versa.journal_article10.1007/s00277-007-0276-817340135000246730300006