Two Leukemic Peripheral Blood Stemlines During Acute Transformation of Chronic Myelogenous Leukemia in a D/D Translocation Carrier

Abstract

Two characteristic malignant cell lines were consistently found in each of two different studies performed at a three month interval in a 53-year-old white female with acute blastic transformation of chronic myelogenous leukemia. One stemline included the Philadelphia (Ph<sup>1</sup>) chromosome; the other, probably derived from the former, showed in addition replacement of an E<sup>17</sup> member by an abnormal chromosome. This marker (M) had symmetrical limbs, each the length of the long arm of the single E<sup>17</sup> identified in these cells. Both leukemic stemlines also carried a D/D translocation similarly present in cells derived from skin cultures. A tentative interpretation was the following: D/D translocation = congenital; D/D translocation + marker Ph<sup>1</sup> = chronic myelogenous leukemia; D/D translocation + Ph<sup>1</sup> + marker M replacing one E<sup>17</sup> (? isochromosome for long arm of E<sup>17</sup>) = acute transformation of the chronic myelogenous leukemia, the final step being regarded as speculative.