Submandibular lateral epidermoid cyst: imaging findings of a rare case

Epidermoid cysts (EC) represent less than 0.01% of all oral cavity cysts. Lateral epidermoid cysts in the neck are very rare. A male patient aged forty-five had a complaint of painless swelling in the neck. A well-circumscribed hypo-echoic mass with internal echoes was detected in the right submandibular regionby ultrasonography. There were round areas inside the cyst with acoustic shadowing. The tissue hardness and the internal nature of the mass were evaluated with sono-elastography. Magnetic resonance imaging showed the mass's location and tissue properties in more detail. Magnetic resonance images revealed a well-circumscribed mass--hyperintense on T2-weighted images, hypo-intense on T1-weighted images--in the right submandibular region that had displaced the submandibular gland and mylohyoid muscle. There was no contrast enhancement in the mass on the contrast-enhanced fat-suppressed T1-weighted MR images. In this case report, we present the imaging features of a rare lateral EC in the submandibular region.