gms | German Medical Science

Objective: The purpose of this retrospective study was to analyze the post-operative outcome of posterior fossa meningiomas.

Methods: A total of 571 meningiomas were operated upon between January 1994 and December 2002. Of these, 113 had a tentorial (38) or posterior petrous bone (32) or petroclival (35) location within the posterior fossa. Foramen magnum and cerebellar convexity meningiomas were excluded from this study. 105 patients were amendable for follow-up including regular ambulatory visits and a questionnaire. The median follow-up including MR imaging was 12 months (0 – 9.8 years).

Results: The median age was 60 years. A female predominance of 85% was observed. At presentation, the most common complaints were dizziness and ataxia (54%), cranial nerve paralysis (33%), hypacusis (33%) and headaches (27%). 105 patients were operated on using supratentorial approaches in 8, infratentorial in 30, suboccipital in 32 and petroclival approaches in 35 cases. The most frequent histological subtypes were meningeothelial (45%) and fibromatous (27%) WHO°I meningiomas. Only two WHO°II tumours were seen. Median tumour volume was 4.33 cm3. Tumour size correlated with appearance of symptoms. Intraoperative radicality was scored by Simpson grade with 51 cases of grade 1 and 2, 24 of °3 and 29 cases of °4. Biopsies (°5) were not performed. Operative radicality was associated with location. Petroclival meningiomas were the most difficult to resect completely. With a median follow-up of 12 months, using post-operative MR imaging, residual or recurrent tumour was diagnosed in 33 cases. Simpson grading, location and tumour volume correlated with residual or recurrent tumour. 3 patients died within 3 months after resection.

Conclusions: The most important predictors of post-operative outcome were Simpson grade, age and location. Long-term follow-up is required for reliable post-operative recurrence assessment.