Long-term surgical outcomes of intracranial epidermoid tumors: impact of extent of resection on recurrence and functional outcomes in 63 patients.

[OBJECTIVE] The authors' objective was to reevaluate the role of microsurgery for epidermoid tumors by examining the associations between extent of resection (EOR), tumor control, and clinical outcomes.

[METHODS] This was a retrospective study of patients with microsurgically treated intracranial epidermoid tumors. The recurrence-free and intervention-free rates were calculated using the Kaplan-Meier method. EOR was graded as gross-total resection (GTR) (total resection without residual on MRI), near-total resection (NTR) (a cyst lining was left in place), subtotal resection (STR) (> 90% resection), and partial resection (PR) (any other suboptimal resection) and used to stratify outcomes.

[RESULTS] Sixty-three patients with mean clinical and radiological follow-up periods of 87.3 and 81.8 months, respectively, were included. Sixteen patients underwent second resections, and 5 underwent third resections. The rates of GTR/NTR, STR, and PR were 43%, 35%, and 22%, respectively, for the initial resections; 44%, 13%, and 44% for the second resections; and 40%, 0%, and 60% for the third resections (p < 0.001). The 5- and 10-year cumulative recurrence-free rates after initial resection were 64% and 32%, respectively. When stratified according to EOR, the 10-year recurrence-free rate after GTR/NTR was marginally better than that after STR (61% vs 35%, p = 0.130) and significantly better than that after PR (61% vs 0%, p < 0.001). The recurrence-free rates after initial microsurgery were marginally better than those after second surgery (p = 0.102) and third surgery (p = 0.065). The 5- and 10-year cumulative intervention-free rates after initial resection were 91% and 58%, respectively. When stratified according to EOR, the 10-year intervention-free rate after GTR/NTR was significantly better than that after STR (100% vs 51%, p = 0.022) and PR (100% vs 27%, p < 0.001). The 5-year intervention-free rate after initial surgery was marginally better than that after second surgery (52%, p = 0.088) and significantly better than that after third surgery (0%, p = 0.004). After initial, second, and third resections, permanent neurological complications were observed in 6 (10%), 1 (6%), and 1 (20%) patients, respectively. At the last follow-up visit, 82%, 23%, and 7% of patients were free from radiological recurrence after GTR/NTR, STR, and PR as the initial surgical procedure, respectively.

[CONCLUSIONS] GTR/NTR seems to contribute to better disease control without significantly impairing functional status. Initial resection offers the best chance to achieve better EOR, leading to better disease control.