Intracranial acute promyelocytic leukemia at presentation-A case-based discussion.

Intracranial disease is a very rare presentation at diagnosis in acute promyelocytic leukemia (APL). The risk associated with this particular presentation is not accounted for when the current risk stratification is based on peripheral counts. Extra medullary disease in general may challenge this risk stratification that commands initial induction treatment of this potentially fatal disease. Here we discuss a case presented at diagnosis with extensive intracranial base of the skull, clivus and sinus infiltration and heavily infiltrated bone marrow yet with low peripheral blood counts and no peripheral blood blasts. Such cases lack evidence of how to treat.