Abstract
A 38-year-old man was referred to us about headache. Acute hydrocephalus and round tumor showing high signal on T1 and low signal on T2 weighted signal at the anterior third ventricle was identified on MR images. The tumor was resected via transventricular approach with a guidance of stereotaxic tool. The tumor was diagnosed histologically colloid cyst, however the mass consisted of firm granules principally. These unusual signals on MR images of colloid cyst may predict the existence of mucin clump inside.
