Abstract: | The recidive-free phases, survival times and the number of long surviging patients were recorded in 64 children with cytochemically differentiated ALL. A significantly more favourable course of ALL of PAS type could be observed as compared with the undifferentiated type and partially with the esterase type, too. According to the present findings the cytochemical examinations of ALL can be recommended in the initial phase of leukaemia as a prognostic evaluation. |