Abstract
OBJECTIVES: Chordoid meningiomas are a rare histologic variant that follow an aggressive clinical course. Here, we examine histopathologic and radiologic features of chordoid meningiomas to identify risk factors for recurrence.
METHODS
Retrospective chart reviews were performed on 11 patients with chordoid meningioma and 15 patients with meningioma with focal chordoid features (<50% chordoid histology) who were treated at a single institution from 2000 to 2015. The median imaging follow-up was 45 months. A blinded radiologic review was performed on chordoid and 224 non-chordoid meningiomas from the same era.
RESULTS
Beyond chordoid histology itself, chordoid meningiomas typically lacked high grade histologic features. In contrast, focal chordoid features were found in meningiomas of all grades, and frequently co-occurred with aggressive histologic features (60%). Recursive partitioning analysis delineated chordoid meningiomas from non-chordoid meningiomas based on high apparent diffusion coefficient (ADC, 73% vs 18%, P=0.0007), hyperintensity on T2-weighted magnetic resonance imaging (82% vs 42%, P=0.04), absence of a cerebrospinal fluid cleft sign (45% vs 77%, P=0.02), and indistinct tumor margins (27% vs 8%, P=0.03). Multivariate analysis identified low ADC (RR 29.1, 95% CI 3.5–462.8, P=0.001), peritumoral edema (RR 8.4, 95% CI 1.2–115.0, P=0.03) and skull base location (RR 5.1, 95% CI 1.2–27.1, P=0.03) as prognostic for local recurrence among meningiomas with chordoid histology. The 5-year local freedom from recurrence and disease specific survival among meningiomas with chordoid histology were 52% and 77%, respectively.
CONCLUSION
Meningiomas with chordoid histology have radiologic features that delineate them from non-chordoid meningiomas, and low ADC, peritumoral edema and skull base are prognostic for an elevated risk of recurrence.