Choice of posterior subtemporal transtentorial approach for tumor resection in deep anteromedial superior cerebellum.

The anteromedial superior cerebellar tumor can be accessed by various routes. For tumor presenting at the cerebellar surface in this region, the optimal approach remains contentious. Furthermore, which of the various routes offers the optimal approach to a tumor that is not present at the cerebellar surface but lies deep anteromedial superior cerebellum is a matter of debate. We report herein the case of a 44-year-old woman with hemangioblastoma deep within the subcortex of the anteromedial superior cerebellum. Preoperative magnetic resonance (MR) imaging and three-dimensional anisotropy contrast MR axonography using diffusion-weighted MR imaging demonstrated that the posterior subtemporal transtentorial (PSTT) approach would provide a shorter surgical corridor, minimal cerebellar split, and better preservation of nerve fibers, compared to the other approaches. Surgical tumor removal was successfully achieved using the PSTT approach. During surgery, the PSTT approach provided an operative field that enabled visualization of the proximal side of the superior cerebellar artery as the tumor feeding vessel. Although the vein of Labbé inserted just into the transverse-sigmoid junction, injury to this vein was avoided using optimal head position, cerebrospinal fluid drainage, and various devices. For patients with tumor located within the subcortex of the anteromedial superior cerebellum, the PSTT approach is recommended as an optimal surgical route. Scrupulous evaluation using preoperative neuroimaging is crucial when deciding on the surgical approach.