Uncommon sonographic findings of an epidermoid cyst in the head and neck

Epidermoid cysts are rare lesions in the head and neck. Most often the are located in the submental region, although they sometimes can impose certain diagnostic problems. We report the case of a 19-year-old girl who presente d with a fluctuant, painless, midline swelling of the floor of her mouth th at had persisted for three months. Ultrasonographic examination showed a 5x 5x4 cm cystic tumor with the unusual aspect of multiple smaller spherical f ormations. The differential diagnosis of the lesion included dermoid cysts, epidermoid cysts, ranula and parasitic lesions. Computed tomography and ma gnetic resonance tomography were not diagnostic. The patient underwent exci sion of the lesion, during which the cyst was completely removed. Histopath ological diagnosis was consistent with an epidermoid cyst. The striking son ographic aspect of multiple spherical formations in the lesion was caused b y multiple spherical keratin formations.