ABSTRACT
T-ALL is known to be associated with bad prognosis within ALL. Morphology of the ten cases studied showed L2 70% while L1 was 30% indicating the more malignant nature of the disease. Haematological blood parameters showed high haemoglobin and platelets and low numbers of blasts in the marrow indicating better preservation of the marrow and suggesting non-marrow origin of the disease. Acid phosphatase reaction was positive in majority of the blasts. P.A.S. stain was negative in majority of the cases while myeloperoxidase and alpha-napthyl esterase was negative. Sheep red blood cells rosettes were negative in a few cases suggesting that surface marker develop at a later stage than cytochemical enzymes since acid phosphatase was positive in all cases. This study shows continental variation of T-ALL since we report low presentation counts and high frequency of L2 in T-ALL. This further explains the more malignant nature of the disease and explain the poor prognosis of ALL in Karachi Children