Hyperleukocytosis during clozapine treatment: A rare presentation of B-cell Acute lymphoblastic leukemia

Clozapine has been widely used as an antipsychotic drug for the treatment of refractory schizophrenia. Unfortunately, a wide range of blood dyscrasias have been reported as adverse effects of this drug. Agranulocytosis has gotten the most clinical vigilance; however, there are substantial reports of other blood dyscrasias associated with Clozapine some more serious than others. Of relevance, there have been previous claims of Clozapineassociated leukocytosis and acute myeloid leukemia. We report the case of a 31-year-old patient who developed Acute lymphoblastic leukemia shortly after starting treatment with Clozapine for refractory schizophrenia. We suggest Clozapine may play a causal role in the development of leukemias in patients taking this medication and we encourage vigilance for such correlation.