Slide 1. 11th Virtual International Conference of the Neurosurgery Research Listserv and the World Neurosurgery Webinar Conference 2021, presented by Mauro Segura, Neurología Segura Director, Morelia Mexico 2021 Slide 4. Epidermoid cysts are slow-growing brain tumors of embryonic origin that manifest later in life.1 The anterolateral cisterns of the brainstem is its most frequent location.2 They represent approximately 1% of intracranial tumors.1 They are present in about 2% of patients presenting as a first symptom a trigeminal neuralgia.2 The study of choice is a high definition MRI Slide 5. We present our experience and philosophy on the surgical approach based on three principles: Preserve the life of the patient. Do not damage the nerve and vascular structures adjacent to the surgical site to avoid neurological sequelae and complications inherent to surgery. Eliminate the cause of compressive neuropathy and relieve symptoms. Slide 6.For this presentation we focus primarily on the anterolateral location of the brainstem of Epidermoid Cyst. Slide 7. Our surgical technique in 10 steps. 1.Lateral decubitus positioning with head rotation 1 inch skin incision in the retromastoid region 2.Musculoskeletal plane dissection to reach the surface of the skull 3.Infra-asterional craniectomy <2cm 5. Durotomy in "<" or ">" 6. Depletion of CSF from the posterior fossa without brain retraction 7. Debulking and tumor resection 8. Treatment of the implant area 9. Hemostatic review of the microsurgical area 10.Hermetic duroplasty and soft tissues Slide 21. Our series of EC cases in the ALCs of the brainstem is one of the largest published in Latin America and, based on the excellent long-term results obtained, we propose this minimally invasive microsurgical approach as the best treatment. Comprehensive anterolateral cisterns of the brainstem as a 3D space concept Non-septate but monocompartmental, non-infiltrative towards the adjacent arachnoid Complete or subtotal excision without implant zone is the goal in the first surgery Due to the rarity of the entity, we recommend that the neurosurgeon interested in treating this type of tumor be trained in laboratories with cadavers, with software for 3D virtual surgery and under the tutelage of an expert neurosurgeon to resolve contingencies that may arise during the curve learning. Neurología Segura Medical Center www.neurologiasegura.net