An unusual karyotype in preleukemia.

A case of a myeloproliferative disorder classified as preleukemia is described in which the patient developed a single, complicated, abnormal karyotype in 100% of the bone marrow cells (45, XY, -2, -5, -7, -8, -11, -12, -13, -14, + t(2;5), +t(11;12), +t(16;17), +17, plus three or four dicentric markers). The possible significance of these unusual, if not unique, chromosome changes is discussed in relation to hematologic and clinical findings and with particular reference to the existing nonrandom patterns of chromosome changes in myeloproliferative disorders and acute nonlymphoblastic leukemias.