"Retrosigmoid approach for resection of an extraventricular choroid plexus papilloma in the cerebellopontine angle" Choroid plexus papillomas (CPP) are uncommon benign brain tumors that usually arise in the fourth ventricle in adults and lateral ventricles in children. Extraventricular CPPs are rare and can be found primarily in the cerebellopontine angle (CPA). We present a case of primary extraventricular CPP in the right CPA successfully resected with retrosigmoid approach. Detailed surgical techniques of retrosigmoid craniotomy and tumor dissection are presented in high definition video with narration. Lee A. Tan, MD, Ricardo B. Fontes, MD, PhD, and Richard W. Byrne, MD Department of Neurosurgery, Rush University Medical Center, Chicago, Illinois