Congenital bilateral ectopic parotid glands: case report and systematic review of the literatures.

Cheek swelling can be attributed to several pathologies, including masseteric hypertrophy, diffuse inflammatory changes and neoplasia. We report an extremely rare case of bilateral cheek swelling as a result of ectopic parotid glands. This case is a young female patient with bilateral ectopic parotid glands superficial to the masseter muscle and the zygomatic arch, demonstrated by the enhanced computed tomography (CT). Medical history, clinical features, videography and management of this case are described. After two years of observation, no significant change in symptoms was observed on this patient. Besides, we conducted a case report and systematic review of cases of ectopic parotid gland. A literature search was performed using PubMed, Web of Science, and Ovid electronic database. A total of 144 papers were retrieved and only one paper was included in the systematic review. In conclusion, bilateral ectopic parotid gland is extremely rare and easily confused with other lumps in the area of head and neck. CT, magnetic resonance imaging (MRI), ultrasound imaging and parotid sialography allow for noninvasive diagnosis of ectopic parotid gland. If the parotid ectopic is highly suspected and the patient does not have obvious symptoms, conservative treatment and long-term observation follow-up are recommended.