摘要
BACKGROUND Teratoma is a common tumor,but rarely occurs in the parotid region.Only nine cases have been reported in the current literature.Although it is generally detected in infancy or childhood,it is commonly asymptomatic.Computed tomography(CT)and magnetic resonance imaging(MRI)have important roles in the diagnosis of teratoma.CASE SUMMARY A 36-year-old man developed a lump located below the left auricular lobule 3 years ago.Physical examination revealed a nearly-circular tumor in the left parotid gland region with a defined border,firm texture,and significant movement.Calcification,fat,keratinized substances,and typical fat-liquid levels was observed on CT and MRI.A diagnosis of cystic teratoma of the parotid gland was established preoperatively and confirmed by postoperative pathology.Following surgery,the patient developed temporary facial paralysis.There was no recurrence of teratoma during the 15-mo follow-up period.CONCLUSION When an asymptomatic mass in the parotid region is identified,parotid gland teratoma should be included in the differential diagnosis.Imaging examinations are helpful in the diagnosis.