抄録
We report the case of a lateral dermoid cyst on the floor of the mouth of a 14-year-old boy. T2-weighted magnetic resonance imaging revealed a high signal and homogeneous density, a finding consistent with that of a ranula. However, atypical findings, such as the appearance of expanded displacement, were also observed. Since the lesion was benign based on the clinical course and biopsy involved a risk of causing a secondary infection, we decided to examine the lesion based on the intraoperative findings. On the basis of the intraoperative findings, we diagnosed the cyst as an epidermoid/dermoid cyst; therefore, total enucleation was performed. A postoperative histopathological diagnosis suggested a dermoid cyst. The postoperative course was good, with no dysfunction observed.