A postprandial neck lump
1. What is this investigation and what does it show? 2. How does this condition present ? 3. How would you manage it ?
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This radiological investigation is a submandibular sialogram showing a calculus within the submandibular duct
just distal to where the duct arises from the gland. Submandibular calculi occur most commonly in young to
middle aged adults. They commonly present with intermittent pain and swelling in the submandibular region
occurring just prior to or during a meal. The swelling is usually the principal complaint, lasting minutes
rather than hours, with the patient symptom-free between attacks. If the gland becomes damaged the swelling may
persist between meals. A foul taste may be noticed as resolution occurs associated with the release The management of submandibular calculi depends on:
If the stone is well forward in the duct and there is no evidence of damage to the gland then simple removal of the stone from the duct is the treatment of choice. Despite its apparent simplicity this procedure is best performed under general anaesthesia with a naso-trachael tube and the pharynx packed to prevent aspiration of the stone. The tongue should be retracted to the contralateral side. The duct should be underun proximal to the stone to prevent it slipping back during manipulation of the duct. There is no need to tie this suture as simple retraction will obliterate the lumen. A lacrimal probe should be placed in the duct and a cut down on to the stone, leaving the terminal 0.5 cm of the duct intact, allows removal of the stone. The incision in the anterior wall of the duct is left open. If the stone is in the proximal part of the duct or the gland is damaged then submandibular sialadenectomy is the treatment of choice. An understanding of the anatomy of the submandibular region is essential to the safe performance of this operation. The submandibular gland has a superficial and deep part wrapped around the posterior border of mylohyoid. The facial artery and vein frequently run through the superficial part of the gland. The mandibular branch of the facial nerve dips into the neck behind the angle of the jaw and curves up over the superficial part of the gland. The duct arises from the anterior border of the deep part of the gland and is crossed superficially by the lingual nerve passing from lateral to medial. The patient should be positioned with a head up tilt, sufficiently steep to collapse the external jugular vein. The head should be placed on a head ring and turned to the contralateral side. To avoid damage to the mandibular branch of the facial nerve the incision should be placed in a skin crease about 5 cm below the ramus of the mandible. The incision should extend directly through platysma. Muscle flaps should be raised protecting the nerve in the upper flap. The inferior border of the gland should be exposed and the superficial part of the gland dissected. Almost always the facial artery and vein will need to be ligated and divided at both the upper and lower borders of the gland. Retraction of mylohyoid will allow dissection of the deep part of the gland and identification of the submandibular duct. As the gland is dissected off hyoglossus the lingual nerve should be identified and preserved. The hypoglossal nerve may also be seen at this time. The duct should be dissected as far forward as possible before being ligated and divided distal to the stone. A suction drain should be inserted and the platysma and skin closed in two layers. Recent papersBull P D. Salivary gland stones: diagnosis and treatment. Hosp Med 2001; 62: 396-399. Goh Y H, Sethi D S. Submandibular gland excision: a five-year review. J Laryngol Otol 1998; 112: 269-273.
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of purulent saliva from the duct. Bimanual palpation will confirm a distended firm submandibular gland with
normal overlying skin. Inspection and palpation of the floor of the mouth may reveal the stone in the distal
part of submandibular duct. As over 80% of submandibular calculi are radio-opaque the diagnosis can often be
confirmed by a plain x-ray. If the stone is clinically apparent a sialogram is not usually required. A stone
impacted in the duct predisposes to ascending infection. Acute submandibular sialitis presents as severe
constant pain in the submandibular region associated with fever and a red, tender enlarged submandibular gland.