Spontaneous Change in Density of Colloid Cyst: An Unusual Phenomenon

Colloid cysts of the third ventricle are benign congenital lesions. They are at times totally asymptomatic or may be detected in the evaluation for headache, neurologic disturbances, or psychiatric disturbances. They may sometimes cause grave consequences such as coma or even sudden death. The radiologic appearance is unique and important for making decisions in the management.

We report a patient with a colloid cyst who presented to us after sudden deterioration in consciouness. It was noted that he underwent brain computed tomography (CT) scan 10 months ago in the evaluation of headache. Compared with previous CT scan, there was a sudden change in the density and size of the colloid cyst with obstructive hydrocephalus. This unique change in the character of the colloid cyst occurred without any intervention. We discuss the possible etiologies behind this phenomenon along with a review of the literature.

This case stands out remarkably because it is only the second case in literature with similar natural history.