Colloid Cyst Presenting as Head Injury

Colloid cysts are mucous- or hyaloid-filled lesions with an outer fibrous layer. These are rare developmental and nonneoplastic malformation. They may be found incidentally, while some cases may present with intermittent headache, rapid neurologic deterioration, drop attacks, and even sudden death. Early recognition of this disease may result in lesser mortality. Here, we present a 22-year-old male with a history of fall while driving his two-wheeler. A diagnosis of colloid cyst of the third ventricle with a head injury was made. Colloid cyst presenting with a head injury is exceedingly rare with only five case reports in the literature. This report may help to support surgical intervention in an asymptomatic patient, as the cyst can predispose head injury with serious consequences. It also stresses the importance of a high degree of suspicion when there is any well-defined radiological abnormality in the region of the third ventricle. A colloid cyst may easily be confused with intracranial hemorrhage due to hyperdensity in head trauma. It can be distinguished by the presence of an accompanying traumatic lesion. The cyst usually has well-defined round margins, and the morphologic appearance and density do not change on a follow-up computed tomography (CT) scan, whereas in hemorrhage the density usually regresses with clinical improvement on serial imaging.