Benign Tumors of Minor Salivary Glands Treatment & Management
- Author: Fadi Chahin, MD; Chief Editor: John Geibel, MD, DSc, MSc, MA more...
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 fine-needle aspiration biopsy (FNAB), current recommendations include preoperative assessment with these diagnostic tools for all salivary gland tumors (SGTs), except perhaps small lesions of the superficial lobe of the parotid gland.
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.
Administer medical and supportive treatment in cases of inflammatory or infectious masses (eg, acute bacterial sialadenitis, mycobacterial disease). Importantly, salivary gland excision is sometimes indicated when symptomatic, recurrent chronic gland infection (eg, parotitis) proves refractory to conservative treatments.
If lymphoma is diagnosed, administer therapy appropriate for the stage and type of lymphoma.
Management of benign SGTs includes complete removal with an adequate margin of tissue to avoid recurrences. This usually implies complete removal of the gland in which the tumor has arisen. Excision is performed with the patient under general anesthesia and without paralysis. Cure is expected in almost all cases when a complete resection with clear margins is performed.
The endotracheal tube is usually positioned in the corner of the mouth opposite to the surgical field.
Minor salivary gland resection
Surgical treatment of minor SGTs depends on the site of origin and the extent of disease. For tumors of the lip or palate, this may simply involve a wide local excision with primary closure. Larger tumors of the parapharyngeal space may require a more complex surgical procedure, as intraoral resection is not recommended.
The options for external approaches to the parapharyngeal space include a cervical-parotid approach (parotid incision with cervical extension) or a cervical-parotid approach with mandibulotomy (see the image below).
Often, an attempt is made to avoid a mandibulotomy when treating benign lesions that arise from the minor salivary glands. Although this procedure does not require a full facial nerve dissection, the inferior division must be located and preserved. By retracting the sternocleidomastoid laterally, the surgeon can identify the internal jugular vein, the external and internal carotid arteries, and cranial nerves IX-XII. In order to access the space, the posterior belly of the digastric and stylohyoid muscles must be divided, followed by the external carotid artery and the stylomandibular ligament. In addition, the styloid process may be resected for delivery of larger tumors and greater visualization.
The key to this procedure is to localize the facial nerve at the main trunk proximal to the gland safely. Include the possibility of total parotidectomy in the preoperative plan. Also discuss the potential need to sacrifice the facial nerve, with immediate grafting, cervical lymphadenectomy, and mandibulectomy.
Superficial parotidectomy remains the initial procedure of choice for benign parotid gland tumors. The incision usually starts just anterior to the ear helix, extends inferiorly below the ear lobe, and then moves anteriorly to parallel the angle of the jaw within a 2 cm distance. Dissection is usually performed sharply down to the superficial parotid fascia. Then, the skin flap is sutured and retracted from the surgical field. Dissection is continued to expose the remainder of the gland anteriorly and the anterior border of the sternocleidomastoid. At this location, the greater auricular nerve is identified and preserved because it carries sensation to the ear lobule and provides the best option for nerve grafting, if needed. Note that, occasionally, deeper-lobe parotid tumors may displace the facial nerve to a more superficial location, where it is easily injured.
In a parotid gland that is being operated on for the first time, a facial nerve stimulator is not used to identify the facial nerve during surgery. However, testing it on the muscle and setting it at 0.5 mA before use is recommended. Its value is realized at the end of the procedure, when it is used to test and confirm the integrity of the facial nerve branches should a transient dysfunction become an issue in the postoperative period.
Submandibular gland surgery
Submandibular gland surgery is performed with the patient under general anesthesia with endotracheal intubation. Head rotation is to the opposite side of the tumor.
An incision is made at the mastoid process and curved along the inferior aspect of the mandible, approaching the midline. The length of the incision is approximately 4-6 cm. Take the incision down through the platysma, leaving the muscle attached to the skin as a musculocutaneous flap. At this point, the marginal branch of the facial nerve is identified and preserved unless it is directly involved with the tumor. The nerve is located just below the muscle and superficial to the facial vessels. The safest technique is to divide the inferior aspect of the posterior facial vein and to raise the flap to the depth of the vessels and nerve.
Start the dissection of the gland at the level of the hyoid bone and the lower aspect of the gland. Identifying the digastric muscle is important because the hypoglossal nerve with the vessels runs in between the gland and the digastric muscle. Dissection continues on the posterior aspect of the gland, superiorly to where the facial artery is located. At this level, the blood supply to the gland is ligated. The lingual nerve is visualized by anterior retraction of the mylohyoid muscle, and the pedicle of the gland is then carefully ligated, with attention to the main trunk of the lingual nerve. Next, the Warthin duct is identified and ligated to conclude the resection.
To complete the procedure, ensure hemostasis, place a suction drain (with or without an outside pressure dressing), and perform a cosmetic layered closure.
Recurrence is usually caused by inadequate excision (spillage) or inoculation. The recurrence rate, as reported after a mean follow-up period of 11.8 years, is as high as 25%.
Use proper hemostasis techniques with suction drains and compression dressing to avoid bleeding and seroma.
Iatrogenic injury is usually recognized during surgery and immediately repaired.
If the facial nerve is sacrificed because of direct tumor involvement, immediate grafting (using the greater auricular nerve or sural nerve) is required.
Transient facial nerve paralysis (paresis) takes a few weeks to resolve spontaneously but can last as long as 6 months. Direct trauma to the nerve, devascularization, or postoperative nerve inflammation is believed to cause paresis.
Frey syndrome is a known complication after parotidectomy, and manifestations range from erythema related to eating to copious gustatory sweating. The cause is believed to be an aberrant connection of the parasympathetic fibers to the sweat gland of the overlying flap of skin. To minimize the chance of the patient developing postoperative Frey syndrome, raise a thick parotid flap just above the parotid fascia.
Salivary fistulae with wound healing are very uncommon.
When a submandibular gland is removed, follow surgical recommendations to avoid unintentional injury to the lingual, hypoglossal, or mandibular branch of the facial nerve.
Beahrs OH, Adson MA. The surgical anatomy and technic of parotidectomy. Am J Surg. 1958 Jun. 95(6):885-96. [Medline].
Spuntarelli G, Santecchia L, Urbani U, Zama M. Minor salivary gland neoplasm in children. J Craniofac Surg. 2013 Mar. 24(2):664-7. [Medline].
Ritwik P, Brannon RB. A clinical analysis of nine new pediatric and adolescent cases of benign minor salivary gland neoplasms and a review of the literature. J Med Case Rep. 2012 Sep 11. 6(1):287. [Medline]. [Full Text].
Venkata V, Irulandy P. The frequency and distribution pattern of minor salivary gland tumors in a government dental teaching hospital, Chennai, India. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2011 Jan. 111(1):e32-9. [Medline].
Wang XD, Meng LJ, Hou TT, Zheng C, Huang SH. Frequency and distribution pattern of minor salivary gland tumors in a northeastern Chinese population: a retrospective study of 485 patients. J Oral Maxillofac Surg. 2015 Jan. 73 (1):81-91. [Medline].
Nag D, Biswas PK, Mandal PK, Bhattacharyya NK, Gautam D, Mukhopadhyay S. Tumours of minor salivary glands--a clinicopathologic study. J Indian Med Assoc. 2012 Aug. 110(8):567-9, 577. [Medline].
Buxton RW, Maxwell JH, French AJ. Surgical treatment of epithelial tumors of the parotid gland. Surg Gynecol Obstet. 1953 Oct. 97(4):401-16. [Medline].
Eneroth CM, Franzen S, Zajicek J. Aspiration biopsy of salivary gland tumors. A critical review of 910 biopsies. Acta Cytol. 1967 Nov-Dec. 11(6):470-2. [Medline].
Conley JJ, et al. Salivary glands and the facial nerve. Tumors of the Minor Salivary Glands. 1975. 263-267.
Cross DL, Gansler TS, Morris RC. Fine needle aspiration and frozen section of salivary gland lesions. South Med J. 1990 Mar. 83(3):283-6. [Medline].
Granick MS, Solomon MP, Hanna DC. Management of benign and malignant salivary gland tumors. Georgiade GS, Riefkohl R, Levin LS, eds. Georgaide Plastic, Maxillofacial, and Reconstructive Surgery. 3rd ed. Baltimore, Md: Williams & Wilkins; 1997. 155-65.
Hanna EY, Suen JY. Neoplasms of the salivary glands. Cummings CW, Fredrickson JM, Harker LA, et al, eds. Otolaryngology: Head and Neck Surgery. 3rd ed. 1998. Vol 2: 1255-98.
Nythus L, Lloyd M, Baker R, eds. Anatomy of the parotid gland, submandibular triangle, and the floor of the mouth. Mastery of Surgery. 3rd ed. Boston, Mass: Little Brown; 1997. 293-312.
Saleh HA, Abbarah T. Intraductal papilloma of the minor salivary gland involving the nasal cavity: is it a distinct histopathologic entity?. Otolaryngol Head Neck Surg. 1998 Jun. 118(6):850-2. [Medline].
Seifert G, Sobin LH. The World Health Organization's Histological Classification of Salivary Gland Tumors. A commentary on the second edition. Cancer. 1992 Jul 15. 70(2):379-85. [Medline].
Townsend CM, Beauchamp RD, Evers BM, et al. Salivary gland tumors. Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice. 16th ed. Philadelphia, Pa: WB Saunders; 2001. 547-52.