2026 Proffered Presentations
S262: EVALUATING THE CLINICAL COURSE OF SPORADIC MENINGIOMATOSIS
Asad M Lak, MD1; Ziyan Zhang, BA2; Shree Pari, BS2; Jeremy Greenlee, MD1; Albert H Kim, MD, PhD2; Bhuvic Patel, MD2; 1University of Iowa; 2Washington University, St. Louis
Background: Meningiomatosis, defined as the presence of two or more spatially separated meningiomas can be associated with significant morbidity owing to the presence of multiple tumors. It can be familial, radiation-induced, or sporadic. Familial and radiation-induced meningiomatosis have been previously studied and are associated with aggressive tumor behavior. However, sporadic meningiomatosis, the most common subtype of meningiomatosis, remains poorly studied regarding natural history, treatment-related morbidity and underlying molecular drivers.
Methods: A retrospective, multi-institutional study was performed to identify patients with sporadic meningiomatosis who underwent surgical resection of at least one meningioma and did not have any underlying risk factors (i.e. history of radiation or underlying syndrome). Baseline demographics (age, gender), tumor characteristics (number, location, WHO grade), treatment characteristics (number of treatments, type of treatment e.g. radiation, surgery, or chemotherapy) and follow-up were documented.
Results: A total of 95 patients were identified. The median patient age was 58 years and 64% (n=61) were female. The median number of tumors per patient was 3, and the most common type was WHO grade 1 (n=100), followed by grade 2 (n=46) and grade 3 (n=11). A total of 57% (n=54) of patients underwent multiple treatments, with a median of 2 treatments per person. The median time to recurrence was 2 years and median follow-up was 2 years.
Among the patients who underwent multiple treatments (n=54), a total of 130 treatments were performed. The median age was 56 years and 78% (n=42) were female. The most common tumor type was WHO grade 1 (n=72), followed by grade 2 (n=35) and grade 3 (n=11). The most common treatment underwent was surgery (n=89) followed by RT (n=36) and chemotherapy (n=5). Approximately 52% (n=68) of the multiple treatments were performed for the same tumor. Patients with specimens available from multiple tumors had different WHO grades in 35% cases (n=10), reflecting heterogeneity among different tumors from the same patient.
Conclusion: This large multi-institutional analysis reveals that more than half of sporadic meningiomatosis patients require multiple surgeries to address the same tumor, suggesting that meningiomatosis-associated tumors behave more aggressively. Interestingly, there is also notable inter-tumoral heterogeneity among tumors within the same patient. This warrants further investigation of molecular drivers of meningioma tumorigenesis and suggests that treatment of each tumor should be considered independently in meningiomatosis patients.
