Diagnosis: Imperforate right submandibular duct
Infants may present with congenital masses in the floor of the mouth from a number of different causes.1 Rarely, a congenital imperforate submandibular duct (Wharton duct) orifice in a newborn can result in a cystic swelling with a bluish, translucent appearance. Failure of canalization of the terminal end of the duct is the cause of this kind of anomaly,2 and in most reported cases, a unilateral swelling is seen at birth.3 The differential diagnoses of this pathologic finding are extensive and include sialolithiasis, mucous retention phenomenon (ranula, mucocele), dermoid cyst, thyroglossal duct cyst, hemangioma, cystic hygroma, and lipoma.4