Intra and extracranial meningiomas involving the temporal bone.

Meningiomas involving the temporal bone are very rare. Until 1964, only 39 cases had been reported in the world literature. Most series reported are very small and a physician is unable, based on his own experience, to acquire a sufficient knowledge about this entity and may raise serious doubts regarding the diagnosis and management of these tumors. In the past nine years the author has encountered five cases of meningiomas involving the temporal bone. This became a stimulus for a thorough research of the world literature of meningiomas in general, with emphasis on temporal bone involvement. Nine more cases were collected from cooperative physicians with whom the author has been associated. These 14 cases are the clinical material analysed in this study. This thesis is divided into three sections: 1. Exhaustive review of the world literature on meningiomas with emphasis on involvement of the temporal bone. 2. A detailed presentation and discussion of the clinical material stressing the importance of the newer diagnostic methods available and the most modern microsurgical techniques used in otological and neurological surgery procedures, applied to the treatment of those lesions. A light microscopic histopathological study of all cases reported is presented. Electronmicroscopy demonstrates the true intracellular nature of an atypical, recurrent meningioma occurring in a child. 3. A critical evaluation of the cases presented and the value of the diagnostic and therapeutic methods applied in this series of patients are here analysed. Conclusions are then drawn based on the experience and knowledge accumulated in this study. The histopathological diagnosis of meningiomas sometimes is difficult. Probably those tumors involve the temporal bone more commonly than has been reported in the literature. Some of these lesions probably are being misdiagnosed as chemodectomas or other neoplasias. Computerized axial tomography, particularly applied to the diagnosis of brain lesions, is the major break-through of recent modern medicine. A noninvasive technique, when used with contrast enhancement, offers great diagnostic possibilities. Early diagnosis of meningiomas and their complete surgical excision are the key factors necessary for a successful result with a good prognosis and a low recurrence rate. Although these tumors are classically considered radioresistant, radiotherapy may play a role in the treatment of incompletely excised lesions or in patients of a poor surgical risk. Further experiences and time will probably lead to more definite conclusions regarding the role of radiation therapy or the combined surgical and postoperative radiation treatment. Of all brain tumors, meningiomas offer the best prognosis.