[Presentation of a case of hematological malignancy in reversed C.P.C].

We report a 68-year old male who was admitted to our hospital with the chief complaint of fatigue. Laboratory examinations revealed: 1) macrocytic anemia; 2) leukopenia; 3) reticulocytosis; 4) reduction in serum folate level; and 5) erythroid hyperplasia in bone marrow. One year later, the patient was admitted again to our hospital. At that time, laboratory data showed: 1) leukocytosis; 2) appearance of blast cells in peripheral blood; 3) normocytic anemia; 4) thrombocytopenia; and 5) predominant proliferation of blast cell(91%) in bone marrow. Blasts showed prominent nucleoli, markedly basophilic cytoplasma with vacuolation and some blebs on cell surface. The cells were negative for peroxidase stain but positive for PAS stain. We describe the evaluation of hematological laboratory data and the diagnosis in this patient.