Abstract
Dermoid cyst of the floor of the mouth is relatively rare and is often difficult to distinguish from ranula. Intra-oral resection of the dermoid cyst is sometimes difficult because of poor visibility. We report a 27-year-old woman with an oral floor cystic mass which had been diagnosed as a ranula at the previous hospital. Magnetic resonance imaging demonstrated a lesion containing multiple uniformly rounded foci. This characteristic finding called “sack of marbles” raised a suspicion of dermoid cyst. We performed intra-oral endoscopic resection with good visualization of the lesion. It was histologically diagnosed as a dermoid cyst. Endoscope-assisted intraoral resection could be useful to treat a cystic mass in the floor of the mouth.
