Factors influencing meningioma recurrence rate.

The authors studied retrospectively 23 recurrent meningiomas of a total series of 277 intracranial meningiomas operated upon in the Department of Neurosurgery, University of Würzburg, between 1983 and 1989. All tumours were diagnosed by CT scan or MRI and operated upon using modern neurosurgical operation technology such as CUSA, Neodym-YAG-laser and if necessary operating microscope. Age, sex and tumour site could not be demonstrated as an influencing factor of tumour recurrence. Histological subtype and cellular criteria (mitoses, nuclear pleomorphism, focal necrosis) also were not predictive for tumour recurrence in the individual case. We found longer recurrence-free intervals after complete tumour removal (Simpson's grade I or II) than after subtotal tumour excision (Simpson's grade III or IV), but this tendency was not statistically significant. Obviously the analysed factors especially histomorphological criteria and surgical grading do not reflect the total biological behaviour of recurrent meningiomas. Further studies on growth kinetics and tumours metabolism may help to solve this problems.