Parieto-occipital interhemispheric transtentorial resection of a falcotentorial solitary fibrous tumor using a 3D-4K exoscope: Technical nuances and illustrative case.

Background: Solitary fibrous tumors (SFTs) are uncommon in the central nervous system (CNS) and tend to mimic meningioma, based on the symptoms and imaging findings. Falcotentorial location is rare. There is almost no evidence regarding resection using a 3D-4K exoscope. Methods: We present the case of a 59-year-old female patient with a tumor adjacent to the falx and tentorium, with extension to the pineal region. Falcotentorial meningioma was considered the first diagnostic possibility. A parieto-occipital interhemispheric transtentorial approach was chosen, guided by neuronavigation and using a 3D-4K robotic arm exoscope (3DRAE); gross total resection was achieved. Postoperatively, the patient presented no complications, and magnetic resonance imaging confirmed complete resection. However, the pathology report indicated a grade 3 SFT. Results: This case highlights the importance of an appropriate approach based on the morphology and anatomical location of the tumor lesion in the CNS. It also highlights the usefulness of neuronavigation and the 3DRAE in tumors located in areas that are highly complex to approach. On the other hand, it is important to remember the difficulty in differentiating a meningioma from an SFT preoperatively, which could lead to complications during surgery. Finally, to the best of our knowledge, this is the first reported case of a falcotentorial SFT intervened via a parieto-occipital interhemispheric transtentorial approach using 3DRAE. Conclusion: Neuronavigation and the 3DRAE were useful for adequate tumor localization, with complete resection and fewer complications. We believe that, in this specific approach, the exoscope proved extremely useful.