Myeloschisis in a six weeks embryo of a leukemic woman treated by busulfan.

A case of myeloschisis in a six weeks old human embryo is reported. The 39-year-old mother was treated by busulfan before and during the early stages of gestation for chronic lymphatic leukemia. Additional histological findings consisted in a decrease of mesenchymal elements together with a somitic disorganisation in the affected area of the embryo. In spite of the well known experience that this drug is well tolerated by leukemic pregnant women, a possible interference of busulfan with the oocyte differentiation in this elderly primipara is proposed.