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.