Subdural extension of recurrent olfactory neuroblastoma. Case report.

A 37-year-old man presented with olfactory neuroblastoma, which apparently recurred as diffuse extension in the subdural space of the cranial vault and spinal column 3 years after initial resection. Head and spinal magnetic resonance imaging with gadolinium demonstrated a subdural lesion. Cytological examination of the cerebrospinal fluid was negative. Histological examination of a biopsy specimen suggested recurrence of the olfactory neuroblastoma. This type of recurrence is very unusual.