OBJECTIVE: We reviewed our series of olfactory groove meningiomas (OGMs) with 
the aim to relate the surgical approach with outcome and to define clinical and 
pathologic predictors of prognosis.
METHODS: Ninety-nine patients who underwent 113 craniotomies at our Institution 
between 1984 and 2010 were entered this study. The relationship between surgical 
approach (bifrontal, fronto-orbito-basal, and pterional) and either tumor 
diameter, extent of tumor resection, complication rate, need of reoperation, and 
Karnofsky Performance Status (KPS) was analyzed. The impact of age (≤ 70 vs. > 
70 years), sex, tumor diameter (< 6 vs. ≥ 6 cm), pre- and postoperative KPS (< 
80 vs. ≥ 80), Simpson grade (I-II vs. III-IV), and World Health Organization 
(WHO) histologic grade (I vs. II-III) on survival was assessed. Kaplan-Meier 
survival curves were plotted and differences in survival between groups of 
patients were compared. A multivariate analysis adjusted for age, pre- and 
postoperative KPS, Simpson grade, tumor diameter, and WHO histologic grade also 
was performed.
RESULTS: The fronto-orbito-basal approach (n = 22) allowed a significantly 
greater percentage of Simpson I-II removals than the bifrontal (n = 70) and 
pterional approach (n = 21) (P = 0.0354 and P = 0.0485, respectively). The risk 
of life-threatening complications trended to be lower in patients operated upon 
either via the fronto-orbito-basal and via the pterional approach than in those 
treated via the bifrontal approach. Retraction-related brain swelling did not 
occur in any case after the fronto-orbito-basal approach (P = 0.0384); however, 
this approach was associated with a greater rate of cerebrospinal fluid leak (P 
= 0.0011). Among prognostic factors, age ≤ 70 years (P = 0.0044), tumor diameter 
<6 cm (P = 0.0455), pre- and postoperative KPS ≥ 80 (both P < 0.0001), Simpson 
grade I-II (P = 0.0096), and WHO histologic grade I (P = 0.0112) were 
significantly associated with longer overall survival. Age (P = 0.0393) and WHO 
histologic grade (P = 0.0418) emerged as independent prognostic factors for 
overall survival on multivariate analysis.
CONCLUSION: In the largest series of OGMs published to date, the bifrontal 
approach was associated with a greater risk of life-threatening complications 
compared with the lateral pterional and fronto-orbito-basal approaches. The 
fronto-orbito-basal approach provided greater chances of total tumor removal 
than the bifrontal and pterional approaches. Two independent factors for overall 
survival of patients with OGM were identified, namely age and WHO grade.