[Hemato-oncological diseases].

Acquired inhibitors of coagulation cause a life-threatening disease. Clinically newly occurring hemorrhagic diathesis combined with prolonged activated partial thromboplastin time (aPTT) time is diagnostically indicative and can be confirmed by a positive plasma exchange test. For thrombotic thrombocytopenic purpura and hemolytic uremic syndrome (TTP-HUS) the diagnosis of Coombs negative hemolytic anemia together with thrombocytopenia should lead to the detection of fragmentocytes in peripheral blood smears. Hairy cell leukemia is a rare subgroup of chronic B-cell neoplasia with the clinical signs of pancytopenia and splenomegaly which characteristically stain positive for CD103. The gastrointestinal stromal tumor (GIST) has nothing in common with classical soft tissue sarcoma based on the activating mutation of the KIT or PDGFRA gene (positivity for CD117). In all of these disorders the correct diagnosis has a major influence on patient outcome. For the case of acquired inhibitors of coagulation immunosuppressive therapy and substitution of coagulation factors (e.g. recombinant factor VIIa) or for TTP-HUS the immediate start of plasma exchange are mandatory. For hairy cell leukemia a very effective treatment exists with purine analogs (e.g. cladribine) and for metastatic inoperable GIST with tyrosine kinase inhibitors (e.g. imatinib).