Secretory Meningiomas: Increased Prevalence of Seizures Secondary to Edema Formation in a Rare Histologic Subtype

OBJECTIVE: Secretory meningioma (SM) is a rare histological subtype known to cause disproportional peritumoral brain edema. Although meningiomas are defined by slow-growth and mostly present with benign clinical symptoms, SM can cause life-threatening deteriorations. The aim of this study is to characterize the potential pitfalls in treatment of SM by illustrating their characteristic clinical features.

METHODS: We analyzed sixty-nine SM patients operated at our institution and compared them to a matched non-secretory meningioma (non-SM) cohort. Retrospective data was analyzed for frequency of seizures as first presenting symptom, maximum corticosteroid use, intensive care unit- and hospital stay. In addition, histological and radiographic data were evaluated for extent of peritumoral brain edema formation, tumor location and -size, in correlation to clinical presentation.

RESULTS: Seizures were observed at a significantly higher rate as first presenting symptom leading to clinical admission in patients with SM (33.3%), compared to the matched non-SM cohort (13%, p=0.008). In SM patients seizures were associated with increased edema formation, while seizures in non-SM rather correlated with tumor size (p=0.007). The clinically more complicated course in SM patients was reflected by increased demand for corticosteroids and a prolonged intensive care unit stay (p<0.001). SM further showed a higher recurrence rate of 35.9%, compared to a cohort of 320 WHO °I meningiomas resected at our institution (p<0.001).

CONCLUSIONS: Our results illustrate the complicated clinical course of this rare histological meningioma subtype. The increased frequency of seizures may enable raised awareness for potential complications and treatment adjustments perioperatively early at clinical admission.