The microgranular variant of acute promyelocytic leukemia(M3v) has been rarely diagnosed in children. The M3v is characterized by bilobed, multilobular or reniform nucleus and cytoplasm with minimal or no granulation in morphology, by t(15;17) in cytogenetics and aberrant expression of CD2 as well as myeloid antigens(CDl3 and CD33) in immune-phenotyping. We report here a case of CD2-positive microgranular variant of acute promyelocytic leukemia with marked myelofibrosis in an 11 year-old girl. She showed the generalized purpura at presentation. Her WBC count was 6,800/μL, hemoglobin 7.9g/L, hematocrit 22.4%, and platelet count 19,000/μL. Peripheral blood showed many promyelocytes whose morphology was typical variant form of M3. The cells were strong positive with aye-loperoxidase stain. Bone marrow aspiration was dry-tapped and the biopsy showed marked myelofibrosis. The result of immunophenotyping was as follows: CDl3 98.8%, CD33 99.6% CD2 71.2%, CD7 2.3%, CDl9 16.1%, HLA-DR 45.0%, 747 negative. Soon after hospitalization, she presented DIC
manifestations and intracerebral ischemia. She received chemotherapy with dexamethasone and VP-16 but induction of remission was failed. At the 78th day of admission, she died of sepsis.

Keywords: CD2, Microgranular variant, Acute promyelocytic leukemia, Myelofibrosis