Other Tumors of the Cerebellopontine Angle

Abstract

IN ADDITION to the acoustic tumor, the cerebellopontine angle is the site of many other diverse tumors whose histologic features depend upon their cell of origin. The most common of these other lesions are the meningioma and primary cholesteatoma. Clinically, all of these tumors may simulate the acoustic tumor, which is by far the most common neoplasm in this area. In this section we will review these other tumors, emphasizing features in the clinical and diagnostic work-up which may be helpful in the differential diagnosis (Table 1). <h3>Meningiomas</h3> Meningiomas of the cerebellopontine angle are felt to arise from arachnoid villi that indent the large and small venous sinuses surrounding the petrous portion of the temporal bone. They may also be found at the dural foramina of exit of cranial nerves such as the porus acousticus or Meckel's cave. Rarely they may arise in the middle ear. Grossly, the surface of