OBJECTIVE Multiple meningiomas account for 1%-10% of meningiomas. This study 
describes epidemiological aspects of the disease and its management, which is 
more challenging than for single tumors. METHODS A consecutive series of adult 
patients with ≥ 2 spatially separated meningiomas was reviewed. Patients with 
neurofibromatosis Type 2 were excluded. The authors collected clinical, imaging, 
histological, and treatment data to obtain information on epidemiology, 
management options, and outcomes of active treatment and surveillance. RESULTS A 
total of 133 consecutive patients were included over 25 years, with a total of 
395 synchronous and 53 metachronous meningiomas, and a median of 2 tumors per 
patient. One hundred six patients had sporadic disease, 26 had radiation-induced 
disease, and 1 had familial meningiomatosis. At presentation, half of the 
patients were asymptomatic. In terms of their maximum cross-sectional diameter, 
the tumors were small (≤ 2 cm) in 67% and large (> 4 cm) in 11% of the 
meningiomas. Fifty-four patients had upfront treatment, and 31 had delayed 
treatment after an observation period (mean 4 years). One in 4 patients had ≥ 2 
meningiomas treated. Overall, 64% of patients had treatment for 142 tumors-67 
with surgery and 18 with radiotherapy alone. The mean follow-up was 7 years, 
with 13% of treated patients receiving salvage therapy. Approximately 1 in 4 
patients who underwent surgery had ≥ 1 WHO Grade II or III meningioma. 
Meningiomas of different histological subtypes and grades in the same patient 
were not uncommon. CONCLUSIONS Multiple meningiomas are often asymptomatic, 
probably because the majority are small and a significant proportion are induced 
by radiation. Approximately two-thirds of patients with multiple meningiomas 
require therapy, but only one-third of all meningiomas need active treatment. 
The authors recommend surveillance for stable and asymptomatic meningiomas and 
therapy for those that are symptomatic or growing.