Tumor recurrence in parasagittal and falcine atypical meningiomas invading the superior sagittal sinus

Objective: Parasagittal and falcine meningiomas are still a challenge in terms of surgical resection. Although maximal safe resection is the main therapeutic approach, numerous postoperative complications can still occur depending on the locations of these tumors. Moreover, previous studies have reported that parasagittal meningiomas have a higher recurrence rate than meningiomas with other locations. Patients, Materials and Methods: We retrospectively reviewed 21 patients with parasagittal and falcine atypical meningiomas [World Health Organization (WHO) grade II], nine of whom had their superior sagittal sinus (SSS) invaded by the tumor. We reviewed the demographic information, operative notes, pathological reports, and clinical and imagistic follow-up reports of each patient over a 5-year time span. Results: All the patients were surgically treated, and the tumor removal was grade II according to Simpson's grading system in 47.6% and grade III in 19% of the cases. The SSS was invaded in 42.9% of the patients. No immediate mortality or morbidity was revealed by our study. Tumor recurrence/progression documented on postoperative imaging amounted to 14.3% and 19%, 12 and 24 months after surgery, respectively. Furthermore, 36, 48 and 60 months after the surgery, the recurrence rate remained the same, namely in 9.5% of the cases. The recurrence was higher in patients with SSS invasion than in patients with no SSS invasion. The tumor recurrence was slightly more predominant in women, i.e., 6% higher than in the male group. Conclusions: In our group of patients with parasagittal and falcine meningiomas, we report a 47.6% Simpson II resection rate and 19% Simpson III resection rate associated with a very low complication rate and no immediately postoperative morbidity and mortality, compared to more aggressive techniques. The recurrence of parasagittal meningiomas predominated after grade III and IV Simpson resection and dural sinus invasion was a negative predictive factor for recurrence. Therefore, the surgery of parasagittal and falcine meningiomas is beneficial, both for tumor control, but also for improving neurological outcome. Aggressive meningioma resection should be balanced with the increased neurosurgical risk.