Colloid cyst curtailed: A case report of spontaneous colloid cyst regression

BACKGROUND: Colloid cysts arise from the roof of the third ventricle and are at risk for obstructing the flow of cerebrospinal fluid (CSF) and causing increased intracranial pressure. With advancements and increased frequency of imaging, colloid cysts are sometimes discovered incidentally. In these cases, the neurosurgeon is faced with the decision of whether to intervene or manage conservatively. CASE DESCRIPTION: A 67-year-old man was discovered to have a colloid cyst when imaging was performed for transient neurologic deficits. CT and MRI brain revealed a 5mm lesion in the third ventricle with characteristics suggestive of the colloid cyst. Except for his initial presentation, the patient did not exhibit any symptoms and was followed with serial imaging. Four years after discovery, the colloid cyst regressed in size. CONCLUSION: The evolution and resolution of colloid cysts remain elusive; however, the discovery of incidental colloid cysts due to more frequent and more advanced neuroimaging emphasize the importance of this topic. The fear of conservative management is acute decompensation due to obstruction of CSF. However, surgical risks may be avoided if these asymptomatic lesions regress and resolve without intervention. Conservative management is a viable option for patients with colloid cysts, who may not only avoid surgery but who might also rarely experience cyst resolution.