Sialolithiasis in an accessory submandibular gland

A 70-year-old patient with no notable pathological history consulted for right submandibular swelling that had been evolving for more than 10 years as well as a sensation of an intraoral foreign body. On physical examination, the swelling was painless and firm; intraoral examination revealed the presence of a hard mass with a stone-like appearance near the right tonsillar region which eroded the mucosa of the floor of the mouth. The computed tomography objectified a right submandibular gland increased in volume and large oval lithiasis (48 x 19mm). The possibility of a calculus developing in the accessory duct was suggested. A right submandibular gland extirpation was performed with removal of a large calculus which was exteriorized in the floor of the mouth, thus leaving a large mucosal defect at this level; this defect was closed tightly with absorbable suturing. During the exploration, we noticed that the Wharton´s duct was normal and the stone seems to be originated from an accessory duct. Post-operative follow-up was uneventful and no recurrence was detected. Sialolithiasis of the accessory salivary ducts of the submandibular gland is extremely rare and slowly progressing due to the conservation of normal salivary flow, but as the stone increases in volume, the duct´s ability to dilate decrease and a sialo-oral fistula therefore appears with a protrusion of the stone in the floor of the mouth. The giant character of the calculus justifies an external surgery which allows avoiding any neurovascular complications and any recurrence.