From January of 1990 to June of 1993 a diagnosis of microangiopathic hemolytic anemia (MHA) was made in 5 out off 121 new patients with malignant tumor. There were 3 females and 2 males, with a mean age of 57 yr (range: 43-75), and a primary tumor in stomach (n = 2), pancreas (n = 1) and of unknown origin (n = 2). In all cases histologic type was adenocarcinoma and diagnosis was obtained by marrow examination. Four patients developed a disseminated intravascular coagulation syndrome. Intravascular deposits of fibrin, intimal proliferation and tumoral microembolisms were noted in 2 cases. Patients did not received chemotherapy, and the median survival was 7 days (range: 3-61).