Indications
The general consensus is that definitive surgical therapy is warranted for any benign or malignant tumor of the major or minor salivary glands. The notable exceptions to this would be certain tumorlike conditions such as lymphoepithelial cysts associated with AIDS and small, asymptomatic hemangiomas.
Although, historically, physicians have advocated surgery without radiographic imaging or FNAB, current recommendations include preoperative assessment with these diagnostic tools for all SGTs, except perhaps small lesions of the superficial lobe of the parotid gland.
Relevant Anatomy
The parotid gland is situated in the musculoskeletal recess formed by portions of the temporal bone, atlas and mandible, and their related muscles. The gland has a superficial and deep lobe, between which runs the extratemporal portion of the facial nerve. The deep lobe is in contact with the parapharyngeal space. The deep cervical fascia surrounds the parotid gland. This fascia has an anteroinferior portion that becomes the stylomandibular ligament, separating the parotid gland from the submandibular gland.
The facial nerve exits the stylomastoid foramen just posterior to the base of the styloid, gives off small branches to the postauricular and posterior belly of the digastric muscles, and then turns anterolaterally. The main trunk then becomes embedded in parotid tissue and divides into temporofacial and cervicofacial branches just superficial to the retromandibular vein and external carotid artery. Beyond this point, the nerve anatomy varies some; however, 5 general peripheral nerve branches exist: frontal, zygomatic, buccal, marginal mandibular, and cervical. Surgical landmarks for the main trunk of the facial nerve include the tragal pointer and the tympanomastoid suture line.
The submandibular gland encompasses most of the submandibular or digastric triangle. Similar to the parotid gland, the submandibular gland can be divided into a superficial and deep lobe based on the relationship to the mylohyoid muscle. The marginal mandibular branch of the facial nerve courses between the deep surface of the platysma and the superficial aspect of the fascia that lies over the submandibular gland. The facial artery and vein are located just deep to this nerve, and ligation and superior traction of these vascular structures can prevent nerve injury. Along the posterior border of the mylohyoid are located the lingual nerve and submandibular duct (Wharton duct). The hypoglossal nerve courses deep to the tendon of the digastric and then lies medial to the deep cervical fascia.
The sublingual gland occupies the same anatomical space as the submandibular gland, located between the mylohyoid and hyoglossus muscles. The gland can often be palpated in the floor of mouth, as it is rather superficial, covered by only a thin layer of oral mucosa.
The minor salivary glands are widely dispersed throughout the upper respiratory tract, including the palate, lip, pharynx, nasopharynx, larynx, and parapharyngeal space. The greatest densities of glands are located in the hard (250 glands) and soft (150 glands) palates.
Contraindications
The only contraindication to surgical treatment of a benign or malignant SGT is an associated medical problem that precludes the use of a general anesthetic.
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