The patient went on to have a resection. 

Histology

MICROSCOPIC DESCRIPTION:

Sections show the wall and lining of a cyst. The lining is composed of simple ciliated cuboidal epithelium in which no atypical features are seen. The wall is composed of loosely compacted

collagen. The features are of a colloid cyst. No evidence of tumor is seen.

DIAGNOSIS: Third ventricle colloid cyst.

Note: this is a duplicate case of case rID: 53164