The prediction of recurrence in meningiomas.

The purpose of this investigation was to examine a large series of surgically removed meningiomas and correlate the microscopic pathological features found in them with recurrence-free survival of the patient or recurrence of the tumour.It has never been clear what information the pathologist can give to the clinician in a patient who has had a meningioma removed-that is, apart from informing him that it is indeed a meningioma.Simpson (1957) summarized the literature on the recurrence of meningiomas and presented his own findings.However, these were mainly based on surgical findings and macroscopic pathology.A detailed study of the significance of the histology of these tumours has not appeared in the medical literature.It would be desirable to be able to give the clinician some pretty firm opinion as to the likelihood of recurrence.Such information together with the patient's age and general health might render radiotherapy unnecessary in a number of cases.It was not the purpose of this investigation to provide a detailed account of the pathology of meningiomas, as such accounts are available elsewhere (Cushing and Eisenhardt, 1938; Courville, 1945; Russell and Rubinstein, 1959).The 181 tumours examined were all from patients treated by or under the care of Mr. Wylie McKissock between 1936 and the end of 1966.All but a very few were admitted either to Atkinson Morley's Hospital, Wimbledon, or the National Hospital, Queen Square, London.All are parasagittal or falcine tumours, as these are of especial clinical interest and will be the subject of a future publication.It is thought that most of the information obtained will apply to meningiomas at other sites.The likelihood of recurrence with various tumour types and pathological features was expressed as a 'recurrence ratio'.This was reached by dividing