CNRS International Colloquium, Held in Paris on June 22-24, 1977

We have studied 24 cases of secondarily leukemic (stage V) lymphosarcoma (LS), 31 cases of "d'emblee" leukemic LS, and ten cases of lymphoid leukemic neoplasias transitional between "d'emblee" leukemic LS and chronic lymphocytic leukemia (eLL). These cases only concern the common types ofthe WHO classification ofLS, i.e., the prolymphocytic, the lymphoblastic, and the immunoblastic. Some cases have also been classified by cell surface markers. The secondarily leukemic conversion occurred in 40% of the lymphoblastic types, in 14% of the prolymphocytic types, and in 17% of the immunoblastic...