Comparison of Clinical Features and Surgical Outcomes of Cystic and Solid Vestibular Schwannoma.

[BACKGROUND] Whether surgical intervention is optimal for the treatment of cystic vestibular schwannoma (CVS) remains an area of debate and active clinical research. This study aimed to compare the surgical outcomes between CVSs and solid vestibular schwannoma (SVS) to support clinical decision-making.

[METHODS] In this retrospective study, a total of 165 patients with vestibular schwannoma who were admitted to a tertiary hospital for microsurgery via the retrosigmoid approach were included. The extent of resection, facial nerve function, and major complications, as documented in medical records and analyzed.

[RESULTS] Patients with CVSs had significantly larger tumor sizes, as indicated by maximal diameter (P = 0.001), a higher rate of tumor with a maximum diameter ≥3 cm (P = 0.030), and a lower rate of internal auditory canal enlargement (P = 0.004), compared with patients with SVSs. Additionally, patients with CVSs had a significantly lower rate of favorable facial nerve function outcomes (House-Brackmann grade I or II) at 3 months postoperatively compared with those with SVS (74.1% vs. 81.4%, P = 0.033). However, when stratified by tumor size (≥3 cm: P = 0.613; <3 cm: P = 0.592), the difference in facial nerve function outcomes between CVSs and SVSs groups was no longer significant. Logistic regression analysis indicated that tumor size was the only factor significantly associated with unfavorable facial nerve function outcomes (P = 0.005).

[CONCLUSIONS] Tumor size, rather than the cystic presentation, was a more significant predictor of postoperative facial nerve function outcomes in patients undergoing microsurgery.