Many different types of tumor may arise in the cerebellopontine angle. The characteristic morphological features of these depend on the tissue from which the tumors arise. Thus there may occur cysts, gliomas, ependymomas, aneurysms, osteomas, meningiomas, and cholesteatomas.1,5 By far the commonest, however, is the acoustic neuroma. All of these space-occupying lesions may produce clinical pictures which are indiscernible from the acoustic neuroma.2 In our series there were eight such cases. There were five meningiomas and three cholesteatomas. This approximately represents a ratio of eight acoustic neuromas to one of the other lesions. Cholesteatomas These tumors, which have also been termed epidermoid or pearly tumors,3,4 usually comprise about 5% of all growths occurring in the cerebellopontine angle. They may originate in the bones of the calvarium. They have been found in both subdural and subarachnoid spaces above and below the tentorium. Generally their growth is quite slow.