Note Added in Proof: In view of the presence of a monoclonal S.Ig on
the “lymphoblasts” of three CLL patients herein reported, we have studied
with Dr. C. Flandrin, three patients (two children and a young adult) having
a tumoral form of “acute lymphoblastic leukemia” and a peculiar appearance
of the leukemic cells similar to those found in nodes from patients with
lymphoblastosarcomas (lymphosarcoma cell leukemia). In all three cases, the
blast cells carried a monoclonal S.Ig (IgG kappa, 1gM kappa and 1gM lambda,
respectively) and the in vitro synthesis of these S.Ig was proven in the single
case where trypsinization experiments were performed. Such rare cases,
usually labeled as acute lymphoblastic leukemia, presumably correspond to
a B cell proliferation.