Thrombotic thrombocytopenic purpura associated with metastatic gastric adenocarcinoma: successful management with plasmapheresis.

A patient with metastatic gastric adenocarcinoma had progressive microangiopathic red blood cell changes, thrombocytopenia with increased marrow megakaryocytes, bleeding, altered mentation, and seizure. Coagulation parameters were inconsistent with disseminated intravascular coagulation; a clinical diagnosis of thrombotic thrombocytopenic purpura (TTP) was made. Plasmapheresis resulted in improvement on two separate occasions. The diagnosis of tumor-associated TTP should be considered in cancer patients. Plasmapheresis may be more effective than plasma transfusion alone in this syndrome, perhaps via removal of tumor-induced immune complexes from the circulation. Aggressive management of this complication seems justified in cancer patients for whom effective chemotherapy exists.