Tornwaldt's cyst is a benign developmental lesion of the nasopharynx, most of all midline located, originating from an outpouching of the pharyngeal mucosa caused by notocord retraction. Usually, the cyst represents an incidental finding of magnetic resonance study. The purpose of this study is to investigate the differential diagnostic aspects of Tornwaldt's cysts, making a comparison with other diseases of nasopharynx on the basis of morphological characteristics and signal, contributing to the previous statistical works.