Preleukemia and leukemia with 12p- and 19q+ chromosome alterations following Alkeran therapy.

Among 20 patients with acute nonlymphocytic leukemia or dysmyelopoietic preleukemia secondary to Alkeran therapy for another tumor, four had a del(12)(p11-p12) and four had a translocation to 19q13 among multiple karyotypic alterations in their neoplastic hematopoetic clones. It is suggested that these two cytogenetic abnormalities may occur nonrandomly in such hemic disorders and may play a limited role in their pathogenesis.