Sudden unexpected death from primary posterior fossa tumors

We report 2 cases of sudden death in which hospital autopsies revealed unsu spected primary posterior fossa neoplasms. The first case was a 3-year-old girl who was found apneic and pulseless in bed and was brought to the hospi tal moribund and could not be resuscitated. Autopsy revealed a 3-cm ganglio glioma that infiltrated nearly the entire medulla. The second case involved a 39-year-old man who was found asystolic and unresponsive in bed. He was resuscitated and maintained on a ventilator for a few hours, after which li fe support was withdrawn. Autopsy showed a 5-cm pilocytic astrocytoma arisi ng from the ventral cerebellum and extending into the fourth ventricle and compressing the brain stem. Previously reported cases of clinically unsuspe cted primary posterior fossa tumors presenting with sudden death are review ed. Hypotheses for the mechanism of sudden death are presented.