Cryptic Acute Promyelocytic Leukemia (APL) Presenting as Seizures in an Adolescent.

There are approximately 800 new cases of acute promyelocytic leukemia (APL) in the United States every year. APL is rarely observed in pediatric populations, and accounts for less than 5-10% of all pediatric cases of acute myeloid leukemia (AML). APL typically presents with symptoms related to the pancytopenia such as fatigue due to anemia, bleeding and bruising secondary to thrombocytopenia, and infections attributed to a lack of functioning leukocytes. The presentation of APL in the central nervous system (CNS) is a rare phenomenon. In addition, APL has a dismal prognosis when found in the CNS. In this case study, we describe a unique presentation of pediatric APL with cryptic insertion of the promyelocytic leukemia (PML)-retinoic acid receptor-alpha (RARA) fusion protein with a surprisingly excellent recovery.