Meningeal carcinomatosis of the cerebello-pontine angle and auditory internal canal

Most of CPA and IAC region neoplasms are benign. Malignant tumors represent about 2% of the lesions and metastatis lesions are about 0,2-2% of all the neoplasms of this region. In a group of 86 patients with meningeal carcinomatosis, 14 patients with CPA and IAC metastatic lesions were identified. In only 1/14 patients hearing pathology was found. All the patients had meningeal carcinomatosis both in cranial and/ or spinal regions and while 6 patients had brain secondary lesions, and 1 a cord metastasis, only 2 patients showed cranial nerves associated secondary lesions, and always along the trigeminal nerves. It seems chat IAC and CPA carcinomatosis is a part of a more general metastatic involvement of meninges, and that the more frequent involvement of VIII cranial nerves depends from the volumetic dimentions of of CPA cisterns and from the long cisternal lenght of these cranial nerves, that allow a more diffuse and a longer contact between the meninges, the nerves and the metastatic lesions floating in the cerebrospinal fluid.