An acute granular lymphoid leukemia with unusual cytochemistry and immunologic phenotype

A 15-year-old Mexican boy presented with an L2 type acute lymphoid leukemia (ALL). Occasional granulated and hand mirror cells were observed, and enzyme histochemistry showed the blasts to be positive for acid phosphatase, beta glucuronidase, and alpha napthyl butyrate esterase. Immunologic studies showed the cells to stain for terminal deoxynucleotidyl transferase and common ALL antigen and to react with B4 (90 per cent), B1 (60 per cent), and B2 (37 per cent) monoclonal antibodies. T-cell-associated antigens (T1, T4, T6, T8, T11) were present in only 10 per cent or less of the cells. Monoclonal antibodies for granulocytes and monocytes were negative. Surface immunoglobulin was absent. Chromosome studies showed a normal phenotype. Clinically, the patient did well, achieving a remission on a high risk ALL protocol. The case shows a marked dichotomy between enzyme histochemistry and immunologic monoclonal antibody markers and is an unusual case of granulated hand mirror lymphoblastic leukemia of pre-B cell origin.