Schwannomas of the greater superficial petrosal nerve – case series, discussion of surgical techniques, and review of literature

Abstract

Background Facial nerve schwannomas account for about 0.8% of all petrous mass lesions. Schwannomas of the greater superficial petrosal nerve (GSPN) are a rare subtype with few case-reports up to date. Case presentations A retrospective analysis of clinical outcomes, radiographic findings and postoperative complication between June 2007 and December 2020 was performed. Four cases of GSPN schwannomas were reported. The presenting symptoms were facial nerve palsy and hearing loss. Imaging studies showed a subtemporal mass on the anterosuperior aspect of the petrous bone, in one case with extraordinary petrous bone and mastoid infiltration and destruction. Three cases were removed through a subtemporal extra- or intradural approach, one case via a combined pre- and retrosigmoid approach. Improvement of facial nerve palsy occurred in one case; new hearing loss was observed in another case. Xeropthalmia was a short-term temporary deficit in three cases. Short- to mid-term follow-up of the patients has not shown any tumor recurrence. Conclusions GSPN schwannomas are rare entities presenting with heterogenous symptoms. Our surgical findings emphasize safe resection. Complete remission is possible by GTR. Since the small data set limits the expressiveness of statements regarding standard of care and alternative therapy options, additional data is needed.

A Rare Case of Greater Superficial Petrosal Nerve Schwannoma

“…This case was unique in that the schwannoma followed the whole course of the GSPN and did not dilate the geniculate ganglion, as has been described in some reports of GSPN schwannoma (2,3). Her tumor also had more linear growth along the nerve, which raised concern for perineural disease, rather than a central mass growth pattern that is typically seen with skull base schwannomas.…”