[Leukemias].

Immunological techniques have been important recently to advancing our knowledge on leukemia. This approach allows a classification of acute lymphoblastic leukemias in different immunological types (T-cell; B-cell; C-ALLA and Null cell leukemia). Classification and typing of the surface antigens of the leukemic blasts is now, together with morphologic and cytochemical characterization of the cells, a fundamental tool for the prognosis and the therapy of the disease.