手术前区分面神经鞘瘤（FNS）和前庭神经鞘瘤（VS）可能具有挑战性，未能区分这两种病理可能会导致潜在可避免的面神经损伤。本研究介绍了两个高容量中心在术中诊断FNS的治疗中的经验。作者突出了可以区分FNS和VS的临床和影像特征，并提供了一种算法，以帮助处理术中诊断的FNS。2021年1月至2021年12月期间，回顾1484例假定的散发性VS切除的手术记录，并识别了术中诊断的FNS患者。回顾性地审查临床数据和术前影像，以确定提示FNS的特征，并确定与良好术后面神经功能（House-Brackmann [HB]级≤2）相关的因素。为疑似VS的术前影像制定了一项预检方案，并提出了术中FNS诊断后的外科决策建议。 共发现19例（1.3％）患有FNS的患者。所有患者手术前均有正常的面部运动功能。在12例患者中（63％），术前影像未显示出提示FNS的特征，其余患者回顾性显示出额叶/迷路面段的微弱增强、耳蜗管扩大/侵蚀或多个肿瘤结节。11名（57.9％）患者接受了后颅窝切开术，其余患者选择经迷路切开术（n = 6）或经颞骨切开术（n = 2）进行治疗。FNS诊断后，6个（32％）肿瘤进行了全切除（GTR）和电缆神经移植，6个（32％）进行了次全切除（STR）和骨质减压处理的听道面神经节段，7个（36％）仅进行了骨质减压处理。进行次全切除或骨质减压处理的所有患者均表现出正常的术后面部功能（HB级I）。在最后的临床随访中，进行GTR和面神经移植的患者的HB级为III（6例患者中的3例）或IV面部功能。肿瘤复发/增长发生在3例患者（16％）身上，他们所有人都接受了骨质减压处理或次全切除。 在假定为VS切除期间诊断FNS是罕见的，但通过保持高度怀疑并在具有非典型临床或影像特征的患者中进行进一步影像检查，其发生率可以进一步降低。如果确实发生术中诊断，则建议采用保守的外科手术管理，仅进行面神经的骨质减压处理，除非对周围结构产生了显着的压迫效应。

Preoperative differentiation of facial nerve schwannoma (FNS) from vestibular schwannoma (VS) can be challenging, and failure to differentiate between these two pathologies can result in potentially avoidable facial nerve injury. This study presents the combined experience of two high-volume centers in the management of intraoperatively diagnosed FNSs. The authors highlight clinical and imaging features that can distinguish FNS from VS and provide an algorithm to help manage intraoperatively diagnosed FNS.Operative records of 1484 presumed sporadic VS resections between January 2012 and December 2021 were reviewed, and patients with intraoperatively diagnosed FNSs were identified. Clinical data and preoperative imaging were retrospectively reviewed for features suggestive of FNS, and factors associated with good postoperative facial nerve function (House-Brackmann [HB] grade ≤ 2) were identified. A preoperative imaging protocol for suspected VS and recommendations for surgical decision-making following an intraoperative FNS diagnosis were created.Nineteen patients (1.3%) with FNSs were identified. All patients had normal facial motor function preoperatively. In 12 patients (63%), preoperative imaging demonstrated no features suggestive of FNS, with the remainder showing subtle enhancement of the geniculate/labyrinthine facial segment, widening/erosion of the fallopian canal, or multiple tumor nodules in retrospect. Eleven (57.9%) of the 19 patients underwent a retrosigmoid craniotomy, and in the remaining patients, a translabyrinthine (n = 6) or transotic (n = 2) approach was used. Following FNS diagnosis, 6 (32%) of the tumors underwent gross-total resection (GTR) and cable nerve grafting, 6 (32%) underwent subtotal resection (STR) and bony decompression of the meatal facial nerve segment, and 7 (36%) underwent bony decompression only. All patients undergoing subtotal debulking or bony decompression exhibited normal postoperative facial function (HB grade I). At the last clinical follow-up, patients who underwent GTR with a facial nerve graft had HB grade III (3 of 6 patients) or IV facial function. Tumor recurrence/regrowth occurred in 3 patients (16%), all of whom had been treated with either bony decompression or STR.Intraoperative diagnosis of an FNS during a presumed VS resection is rare, but its incidence can be reduced further by maintaining a high index of suspicion and undertaking further imaging in patients with atypical clinical or imaging features. If an intraoperative diagnosis does occur, conservative surgical management with bony decompression of the facial nerve only is recommended, unless there is significant mass effect on surrounding structures.