[Clinical significance of cytochemical findings of childhood acute lymphoblastic leukaemia (author's transl)].

The initial bone marrow smeasrs of 821 children with ALL have been cytochemically analysed. (PAS-, acid phosphatase-(SPH), peroxydase-(POX), alpha-N-esterase-(EST)reaction) with regard to presenting clinical data and course of disease. Granular reactions of PAS and SPH were not meaningful in this respect. The paranuclear SPH-reaction was associated with high incidence of mediastinal mass, high peripheral blas count and male preponderance. All 5 patients with histories of more than 12 weeks duration belongs to the PAS-type of ALL (cloddy reaction). The PAS-type showed a higher incidence of CNS-leukaemia and generally a less favorable prognosis as compared to the UND-type. Thereby a high proportion of PAS positive cells, independently of other risk factors, indicates a better prognosis. The highterto neglected weak EST-reaction (Grad I and II according to Löffler) seems to signalise a clincally distinct subtype of ALL with a younger age distribution maximum as compared to the UND-type, low incidence of risk factors, high rate of remissions lasting more than 2 years but unfavorable endprognosis.