Chondrosarcoma of the Petrous Apex and Posterior Fossa: A Case Report and Literature Overview of a Combined Approach to Resection.

Aim: In this study, we aimed to provide our initial experience with a novel combined approach resection of chondrosarcomas of the skull base and petrous apex (ChPA) and posterior cranial fossa by employing middle cranial fossa and retrosigmoid (RS) approaches with an augmented reality and virtual reality (AR/VR) system.

Case presentation: A 66-year-old female patient was referred to our department owing to the growth of a left petrous apex lesion noted in computed tomography (CT) and magnetic resonance imaging (MRI) scans 10 years earlier. Her symptoms included headache, imbalance, and left-sided hearing loss. The lesion was resected via a combined extended middle cranial fossa (xMCF) and RS approach, gross total resection (GTR) and preservation of hearing and facial nerve function. The tumor was World Health Organization (WHO) Grade II, extending from the left petrous apex (PA) to the posterior fossa, cerebellopontine angle (CPA), and internal auditory canal (IAC). We also performed a systematic literature review of chondrosarcomas involving the skull base.

Results: The patient tolerated the procedure well and was discharged without complications or neurological deficits on postoperative day 6 with normal facial nerve function and stable hearing as observed prior to surgery.

Conclusions: Preoperative planning for the surgical approach must be carefully evaluated and individualized for each patient while considering the experience of the surgical team. GTR remains the preferred treatment for ChPA, preferably via an approach capable of preserving the facial nerve and hearing function. The xMCF approach, along with the RS approach for petrous apex lesions extending to the posterior cranial fossa/CPA with reconstruction of the skull base, appears to be a safe approach.