Multifocal supratentorial diffuse glioma in a young patient with Ollier disease.

Ollier disease is a rare disorder characterised by the development of multiple enchondromas in long bones. Here we present a 19-year-old man with Ollier disease who also developed three synchronous brain tumours. Craniotomy, biopsy and debulking was performed for one lesion followed by a period of observation, and 9 months later he underwent a second craniotomy and debulking for symptomatic progression. Histopathological examination revealed a diagnosis of multifocal diffuse glioma (World Health Organization grade II). This report highlights the increased incidence of primary brain tumours in patients with Ollier disease and identifies the importance of screening patients with Ollier disease for primary neoplasms.