Intracranial aneurysms presenting as mass lesions.

Giant aneurysms within the carotico-basilar system usually differ in their symptomatology from the more common forms of intracranial aneurysms. By virtue of their size they may act as space occupying lesions and compress neighbouring structures. Diagnosis of these aneurysms as well as determination of position and size cnanot be carried out by clinical examination alone. Radiology with its special procedures is essential in confirming this diagnosis.