Lung adenocarcinoma metastasizing to cerebellopontine angle schwannoma (collision tumor).

Collision tumors are composed of two histologically distinct neoplasms which present at one location. Collision of a malignant tumor originating outside the central nervous system with a primary intracranial neoplasm is a rare event. Here we report on a CPA schwannoma containing a metastasis of adenocarcinoma in a 57-years old woman. Searching for the primary tumor resulted in the detection of a carcinoma in the superior lobe of the left lung.