[Arachnoid cyst with consecutive brain stem atrophy, hypoglossal nerve paresis and tongue atrophy].

We report the pathological anatomy of a patient aged 77 years at the time of death, who suffered from an arachnoid cyst situated near the right lower olive nucleus. This led to palsy of the hypoglossal nerve and partial gliosis of the brainstem with consecutive hemiatrophy of the tongue. This lesion did not seem to have any further effects onto clinical presentation. The patient died of a fulminant lung embolism and also presented an adenocarcinoma of the lung.