SAN DIEGO (EGMN) - High hyperploidy - 50 or more chromosomes - has been recognized since the 1980s as a favorable prognostic feature in children with B-lineage acute lymphoblastic leukemia, but it appears that the best results occur in patients who have 58 or more chromosomes.Patients with B-lineage acute lymphoblastic leukemia (B-ALL) who had a modal number of chromosomes (MNC) ranging from 58 to 66 had a 6-year event-free survival rate of 99% in a study reported at the annual meeting of the American...