Atypical choroid plexus papilloma: Diagnosis and differentials: A case report.

Atypical choroid plexus papilloma is a rare World Health Organization grade 2 intraventricular tumor arising from the epithelium of the plexus choroid with intermediate clinical-pathological features between the benign choroid plexus papilloma and the malignant choroid plexus carcinoma. The main criteria for differentiation are histopathologic, with difficulties in distinguishing it from choroid plexus papilloma based on imaging features. We report the case of a 4-year-old female presenting with headaches and altered mental status. Brain magnetic resonance imaging revealed a right lateral ventricular mass with some atypical characteristics, which were confirmed on pathological examination as an atypical choroid plexus papilloma.