The Atypical “Diving” Lesion: Congenital Dilated Imperforate Submandibular Duct

A congenital dilated imperforate submandibular duct is a rare condition that presents early in neonates. Treatment can vary considerably from other lesions more commonly found in the floor of the mouth. Here we describe the case of a 1-week-old neonate with a fluctuant lesion in the floor of the mouth, ultimately diagnosed as a congenital dilated imperforate submandibular duct. We then discuss the imaging characteristics, differential diagnosis, and treatment of the condition.