A 4-year-old girl presenting with facial palsy, found to have increased delta neutrophil index, and diagnosed with acute myeloid leukemia with extramedullary infiltration

ABSTRACT

Although Bell's palsy is the most common cause of facial palsy in children, some cases have potentially fatal causes. We report a rare case of isolated facial palsy in a 4-year-old girl whose diagnosis was acute myeloid leukemia with extramedullary infiltration. The findings of laboratory investigations were nonspecific at presentation except that the delta neutrophil index was 34.5% (reference range, 0%–5%). To avoid hasty diagnosis of Bell's palsy in children with isolated facial palsy, vigilant differential diagnosis and workup are recommended.