Terminal deoxynucleotidyl transferase negative acute lymphoblastic leukemia in two offspring of mothers exposed to diethylstilbestrol (DES) in utero.

We report two children with leukemia who were born to diethylstilbestrol (DES)-exposed mothers. The children were 2 and 6 years old at diagnosis and the lymphoblasts expressed the unusual terminal deoxynucleotidyl transferase negative phenotype. Both children completed induction and maintenance therapy and are alive 6 and 4 years from diagnosis. The role of DES as a transplacental carcinogen is reviewed, and a hypothesis for the target cell interaction is proposed.