Submandibular ductal fistula: an obstacle to sialendoscopy.

IMPORTANCE: Submandibular fistula is a rare condition that presents diagnostic and treatment challenges. Accurate diagnosis may be achieved by means of thorough physical examination, proper imaging, and usually surgical exploration. We describe the clinical significance of aberrant submandibular ductal fistula or ostium and discuss our dilemmas during sialendoscopy in 2 patients with repeated submandibular glandular swelling. OBSERVATIONS: Two patients had submandibular ductal abnormalities. The first patient was found to have the ostium of the submandibular duct in an unusual anatomical location at the posterior floor of the mouth, which was identified during surgical exploration of the floor of the mouth. The second patient was found to have a submandibular ductal fistula into the floor of the mouth proximal to a calculus in the main duct (which was severely atrophic and could not be cannulated). CONCLUSIONS AND RELEVANCE: The precise etiology and pathogenesis of sialo-oral fistula formation are currently unknown but could be extrapolated from previously described syndromes involving ductal obstruction and inciting damage in other regions of the body. Consideration of submandibular fistula in the differential diagnosis may spare the patient morbidity of redundant invasive procedures.