Symptomatic ecchordosis physaliphora mimicking as an intracranial arachnoid cyst

Ecchordosis physaliphora (EP) is a rare, benign tumor derived from the notochordal remnants. Usually slow growing with an indolent course, most cases are incidental findings on autopsy. Limited data exists on symptomatic patients with EP. Diagnosis mainly relies on correlating histopathologic findings confirming the notochordal elements with MRI. We herein present a middle aged woman with symptomatic EP in the pre-pontine cistern that mimicked an arachnoid cyst on preoperative scans. Additionally, we emphasize the pathological and radiological characteristics of EP that could aid in prompt diagnosis of the lesion with emphasis on considering EP as a differential for mass lesions localized in the pre-pontine cistern.