Introduction
Primary filum terminale ependymoma (PFTE) is a unique type of ependymomas and locates on extramedullary site. However, the clinical features and prognostic factors of PFTE are still unknown due to its rarity.
Aim
This study aimed to evaluate the clinical features, outcomes, and prognostic factors of PFTE in the largest series of cases.
Result
Thirty‐eight patients were included in this study. Gross total removal (GTR) of the tumors was achieved in 33(87%) patients. Five (13%) patients had subtotal resection (STR). For the residual tumors, postoperative radiotherapy increased the interval between the first surgery and tumor regrowth (P = 0.063). Six patients had local recurrence/progression. Univariate analysis identified STR(P = 0.001), unencapsulated tumor (P = 0.018), tumor involving more than two vertebral columns (P = 0.005), and tumor invading sacral canal(P < 0.001) as predictors of tumor recurrence. In addition, 36 (95%) patients had stable or improved neurological status directly after surgery. Klekamp–Samii score was better correlated with the symptoms than McCormick scale.
Conclusion
Extent of surgical removal, tumor size, tumor location, and the integrity of tumor capsule are the prognostic factors of PFTEs, and the intrasacral PFTEs always have a poor prognosis.