[Intracranial giant osteochondroma with unusual clinical features].

A case of giant osteochondroma arising from the paramedian skull basis was reported because of unsual clinical features in cranial nerve involvement and pyramidal tract signs, and especially because of sudden death due to intracranial hemorrhage. The patient was a 24-year-old male, who had been followed for over 3 years and 9 months, and received two operations because of bilateral extension of the tumor. During follow-up he had experienced frequent euphoric spells untill mental deterioration became evident. Then he went suddenly into deep coma and intracranial hemorrhage was found with CT scan. Hemorrhage was probably attributed to the marked stretching of cerebral arteries around tumor, although autopsy could not confirm the source of hemorrhage. Neurological characteristics of a giant osteochondroma arising from the skull basis were described in comparison with over skull basis tumor such as chordoma, and special reference was made for CT scan diagnosis.