Surgical management of de novo metastatic meningioma of the spine: An underestimated issue for WHO grade II/III meningiomas

Objectives: Meningioma is a slow-growing neoplasm derived from meningothelial cells. Extradural metastasis of WHO grade II/III meningiomas is relatively rare, and spinal metastatic meningiomas (SMM) have only been described in individual case reports. The aim of the present study is to discuss the clinical features and treatments of SMM patients.

Methods: Fourteen SMM patients who received surgery in our center between 2010 and 2020 were reviewed retrospectively. Possible prognostic factors affecting local progression-free survival (LPFS) and overall survival (OS) were analyzed by log-rank analysis.

Results: Our series comprised nine men and five women, with a median age of 49 years. The interval from the primary treatment to SMM varied from 1 to 11 years. Lesions were mainly located in the lumbar-sacral region (7/14, 50.0%), followed by the thoracic spine (5/14, 35.7%) and cervical (2/14, 14.3%) spine. The median follow-up period was 42.7 months, during which six patients (42.9%) passed away. Local tumor progression was detected in four patients (28.6%). Log-rank analysis indicated that circumferential surgery was associated with good LPFS, whereas WHO grade III and visceral metastasis were factors adversely affecting OS.

Conclusions: SMM is a challenging clinical entity, usually occurring in the fourth to fifth decades of life. Circumferential surgery is associated with good LPFS. WHO grade III and visceral metastasis are factors adversely affecting OS of patients with SMM. Long-term follow-up is recommended for patients who have received surgical treatment for primary meningiomas (Simpson Grade III/IV), especially for WHO III lesions.