Comparison of enzyme-cytochemical findings and immunological marker investigations in acute lymphatic leukemia (ALL).

APh-activity and PAS-positive deposits were studied in 50 cases of ALL, classified as T-ALL and O-ALL according to immunological marker investigations. Correlation between morphological features of the cells and APh and PAS reactions, as well as between morphology and immunological markers was not detected. APh-activity in general was stronger in T-ALL (R+ and R-), while PAS-content was more pronounced in O-ALL. The results suggest that cytochemical methods, especially APh and PAS reaction, are valuable to distinguish T-ALL from O-ALL but not reliable enough to replace immunological marker investigations.