Preoperative identification of meningiomas that are highly likely to recur

Although generally they are well-circumscribed benign tumors, meningiomas recur even after complete removal. The aims of this study are to identify preoperatively groups of patients who have a high risk of meningioma recurrence by reviewing their clinicoradiological features and to plan appropriate treatments.

One hundred one patients who underwent macroscopically complete removal of meningiomas were observed postoperatively for at least 5 years or until tumor recurrence. Preoperative radiological findings and clinical characteristics were assessed. Fifteen meningiomas recurred during the follow-up period, which extended to a maximum duration of 18 years. On univariate analysis, tumor size and shape, relation to the major sinuses, calcification, bone changes, and characteristics of the tumor-brain interface were significant predictive factors for recurrence. Patient age and gender were not deemed significant. Multivariate analysis revealed that only the shape of the tumor was significant; both "mushrooming" and lobulated meningiomas were more likely to recur than round ones. Recurrences most frequently occurred at the edge of the dural resection after a Simpson Grade I removal, whereas local recurrences were predominant after a Simpson Grade II or III removal.

Meningiomas with mushrooming or lobulated shapes should be treated more aggressively with a wider dural excision. This is not usually necessary for round tumors, although it may be beneficial in younger patients.