Peritumoral Edema and Surgical Outcome in Secretory Meningiomas: A Matched Cohort Analysis

Introduction: Secretory meningioma (SM) is a rare subtype of benign meningioma that has been reported to cause significant peritumoral edema. As a result, patients with SM may have a more severe presentation and possibly increased postoperative medical, neurologic, and surgical complications. A few studies have described cohorts of SM patients, but have not been matched to controls to see if disease characteristics and outcomes differ significantly from other benign meningiomas. Our aim was to compare patients with secretory meningioma to patients with other nonsecretory WHO grade I meningiomas and examine disease characteristics such as peritumoral edema, postsurgical outcomes, and recurrence.

Methods: A retrospective review of all patients who underwent surgery and had pathologically confirmed SM between 2000 and 2017 was performed. Subsequently, a 1:1 matched cohort was populated on the basis of tumor location and size to nonsecretory grade I meningioma. Location was stratified in 4 categories: convexity/falcine, anterior fossa, middle fossa, and posterior fossa. Size was stratified as 0–2.0 cm, 2.1–4.0 cm, and 4.1–6.0 cm. There were no SM patients with tumor size greater than 6.0 cm, and therefore all controls with larger tumor size were excluded. Data were described using medians and ranges for continuous variables, and counts and percentages for categorical variables. Study groups were compared on clinical characteristics and outcomes using logistic and cumulative logit generalized estimating equations (GEE) regression models, adjusting for subject pairs and the matching variables size (treated continuously) and location, and the adjusted odds ratios for the associations between study group and outcome were estimated. All analyses were performed on a complete-case basis. Therefore any SM patient that had a particular variable missing was excluded along with the matched control from that specific analysis. All tests were two-tailed and performed at a significance level of 0.05. SAS 9.4 software (SAS Institute, Cary, North Carolina, United States) was used for all analyses.

Results: There were 57 patients who met inclusion criteria and were subsequently matched with 57 control patients. After adjusting for size, location, and pair, the odds of an SM patient being in a more severe T2 edema grade category was 8.9 (95% CI: 3.8–21.1; p < 0.001) times the odds of a control patient. After adjusting for matching variables, the odds of any T2 edema was 6.2 (95% CI: 2.2–17.6; p < 0.001) times higher in the SM group as compared with the control group. The adjusted odds of having a complication (medical, neurologic, or surgical) was 3.2 (95% CI: 1.02–9.9; p < 0.046) times higher in the SM group compared with the control group. Simpson grading, overall neurologic status post-op, and recurrence were not significantly different between SM and control patients.

Conclusion: Patients with secretory meningioma have significantly greater odds of having peritumoral edema and any medical/neurologic/surgical complication when compared with patients with other nonsecretory WHO grade I meningiomas of a similar size and location.