Tumefactive demyelination following in vitro fertilization (IVF).

Tumefactive demyelination (TD) is a solitary cerebral demyelinating lesion clinically and radiologically mimicking brain tumors. It can occur in isolation or may be rarely associated with other demyelinating diseases. The underlying pathogenic mechanisms are unknown. We present the first report of TD following in-vitro fertilization (IVF) in a 36-year-old healthy woman who developed subacute right hemiparesis shortly after a scheduled IVF cycle. Evaluation revealed left hemispheric space-occupying lesion pathologically diagnosed as TD. Treatment with intravenous methylprednisolone promptly resulted in a clinical and radiological improvement maintained thereafter. This report confirms and expands the spectrum of inflammatory demyelinating conditions associated with IVF and suggests possible hormonal influence in the development of TD.