Karyotypic findings in a case of prolymphocytic leukemia with a history of radiation exposure.

Cytogenetic examination, utilizing B- and T-cell mitogens, of the peripheral blood lymphocytes of a patient with the prolymphocytic variant of chronic lymphocytic leukemia (CLL) and a history of radiation exposure revealed two abnormal clones. One clone with 48 chromosomes (+t(6;12),6q-, +12,14q+) may be derived from CLL cells, whereas the clone with 46 chromosomes and a ring #11 possibly originated from normal T and/or B cells affected by past irradiation.