A colloid cyst is a malformation composed of an amorphous, gelatinous material surrounded by epithelial and connective tissue. It is typically located in the third ventricle, leading to signs of increased intracranial pressure and hydrocephalus. In this case report, we discuss a classic presentation of a patient presenting with a colloid cyst of the third ventricle. This includes the patient's symptoms before arriving at the emergency department and presentation upon arrival and during their hospital stay. We also discuss the diagnostic approach to colloid cysts, providing radiographic imaging to support the diagnosis. Finally, we discuss the approach to treatment of a colloid cyst, including temporizing measures to relieve symptoms and definitive measures for removal of the colloid cyst. The overall approach from diagnosis to management to definitive treatment of a colloid cyst requires an interdisciplinary approach but prompt recognition of the signs and symptoms in the ED can decrease both morbidity and mortality associated with this potentially fatal diagnosis.
© 2021 The Authors. JACEP Open published by Wiley Periodicals LLC on behalf of American College of Emergency Physicians.