A Case of Acute Promyelocytic Leukemia with Abnormal Chromosome (4N)

Abstract

A 25-year-old female with acute promyelocytic leukemia and tetraploid blast cells is reported.
She was admitted to our hospital with bleeding tendency, anemia and fever. Blood examination revealed 50 per cent promyelocytoid cells in the peripheral blood and 67.2 per cent in the bone marrow.
Despite an intensive chemotherapy along with heparin, she died of intracranial bleeding 7 days after admission. Of the leukemic cells, 35.7 per cent were bi- and trinucleated and the rest mononuclear. Cytogenetic studies demonstrated a true tetraploid karyotype with 92 chromosomes in 60 per cent of the peripheral white cells and in 76 per cent of the bone marrow cells. The leukemic cells examined by light microscopy showed numerous fine azurophilic granules throughout the cytoplasm and transmission electron microscopy disclosed these cells to have two kinds of granules; the one with high density was smaller than mitochondria and another with low density was a little larger than mitochondria.
Implication of the presence of tetraploidy was discussed.