Seizures as a presentation of a pelvic neuroblastoma in a 5-month-old infant.

Epilepsy is a very uncommon first manifestation of a neuroblastoma. A 5-month-old healthy infant presented with acute onset seizures and developmental regression. Extensive investigation was remarkable for urinary vanillylmandelic acid and homovanillic acid peaks. Abdominopelvic magnetic resonance imaging (MRI) disclosed a presacral unresectable pelvic neuroblastoma. Chemotherapy and monthly dexamethasone pulses were administrated. Seizures stopped 3 days after the first pulse of dexamethasone. At 3-year follow-up, the patient is asymptomatic and has normal neurologic and developmental examinations. This case illustrates an impressive clinical and electroencephalographic (EEG) improvement on corticosteroid therapy, raising several hypotheses, including the possibility of a nonclassic paraneoplastic neurologic syndrome.