Trisomy 5 as a sole cytogenetic abnormality in pediatric acute lymphoblastic leukemia.

We describe a case of pediatric acute lymphoblastic leukemia (ALL) with trisomy 5 as a sole cytogenetic abnormality. A comparison is made with the two cases of adult acute lymphoblastic leukemia with trisomy 5 in the literature. This rare cytogenetic abnormality may portend an especially poor prognosis in patients with ALL.