The Case of the Disappearing Colloid Cyst

Spontaneous regression of colloid cyst on the third ventricle: a case report with the review of the literature

Background

Colloid cyst (CC) is a rare and benign cyst found in the third ventricle near the foramen of Monro. Although the role of surgical resection is well established in symptomatic large-sized CC, it remains debatable whether surgical removal of CC with no symptoms or minimal symptoms is necessary.

Case presentation

A 49-year-old male patient visited our institute for incidentally detected intracranial mass. MRI demonstrated typical, 12 mm-sized CC located in the third ventricle. It was noticed that the cyst spontaneously decreased in size from 12 mm to 4 mm on MRI at 18 months after the first visit.

Conclusion

Although spontaneous regression is a very rare phenomenon in CC, regular imaging study and frequent neurologic examination can be an alternative option for well-selected, asymptomatic cases.

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.