Not a chondroma, but a cartilaginous choristoma of the bony external auditory canal

When the small white mass is found at the anterior wall of the bony external auditory canal (EAC) just in front of the short process of the malleus, the differential diagnosis of cartilaginous choristoma (CC) besides exostosis, osteoma, and keratoma should be included. CC of bony EAC is not as rare as it has been thought to be. Furthermore, it is very surprising that the term chondroma has been wrongly used to describe CC in many previous studies. In this report, I present my clinical experience with four patients with CC in the bony EAC and discuss the clinical importance of CC in differential diagnosis.