Benign Tumors of Major Salivary Glands Clinical Presentation

Updated: Oct 26, 2015
  • Author: Fadi Chahin, MD; Chief Editor: John Geibel, MD, DSc, MSc, AGAF  more...
  • Print
Presentation

History and Physical Examination

The classic presentation of a benign salivary gland tumor (SGT) is a painless, slow-growing mass on the face (parotid), the angle of the jaw (parotid tail, submandibular gland), or the neck (submandibular gland), or else a swelling at the floor of the mouth (sublingual gland). A sudden increase in size may be indicative of infection, cystic degeneration, hemorrhage inside the mass, or malignant degeneration. Benign SGTs are almost always freely mobile, and, for masses that arise in the parotid gland, facial nerve function is typically unaffected. [6]  (See the images below.)

Right submandibular benign salivary gland tumor in Right submandibular benign salivary gland tumor in a 42-year-old woman.
Pictures before and after treatment for a benign m Pictures before and after treatment for a benign mandibular gland tumor. Specimen picture of the gland.

Because of the multiple and varied sites of minor salivary glands, the presentation of benign tumors in these sites may be less specific. For example, bleeding and airway compromise may be the first signs of minor SGTs of the nasal septum, whereas tumors of the base of the tongue may present with dysphagia and a globus sensation. The authors have each observed one patient treated for a pleomorphic adenoma of the nasal septum and the base of the tongue. Benign tumors of the parapharyngeal space may present as trismus. Differentiating a benign, space-occupying lesion from one that is truly invading the masseter and pterygoid musculature is important.

Signs of a malignant lesion (eg, new onset of pain, facial nerve weakness, rapid growth, paresthesias, hoarseness, skin involvement, a fixed lesion, and cervical lymphadenopathy) must be ruled out.

Next:

Tumor Classification

Tumors of the salivary glands are classified on the basis of their cytologic, architectural, and biologic characteristics. The World Health Organization classification of 1992 groups both benign and malignant tumors into epithelial and nonepithelial categories, as follows:

  • Benign epithelial tumors include pleomorphic adenoma, Warthin tumor, monomorphic adenoma, intraductal papilloma (IDP), oncocytoma, and sebaceous neoplasms
  • Benign nonepithelial tumors (mesenchymal origin) include hemangioma, angioma, lymphangioma (cystic hygroma), lipoma, and neural sheath tumors
  • An additional category of tumorlike lesions includes necrotizing sialometaplasia, benign lymphoepithelial lesions, cystic lymphoid hyperplasia (in persons with AIDS), and salivary gland cysts

Benign epithelial tumors

Pleomorphic adenoma

Pleomorphic adenomas (benign mixed tumors) are the most common tumors of the salivary gland and are most often located in the tail of the parotid gland. When found in the minor salivary glands, the hard palate is the site most frequently involved, followed by the upper lip. (See the images below.)

Note the 12-mm right parotid, smoothly marginated, Note the 12-mm right parotid, smoothly marginated, multilobulated, solid lesion, without focal calcification or necrosis. This was proven to be pleomorphic adenoma.
Note the 2 X 1.5-cm uniformly enhancing, smoothly Note the 2 X 1.5-cm uniformly enhancing, smoothly marginated mass in the superficial right parotid gland without necrosis or calcification, which is consistent with an epithelial neoplasm such as pleomorphic adenoma.

These tumors were termed pleomorphic because of the epithelial and connective tissue components that compose them in varying degrees. Their gross appearance is a round, smooth mass with a thin, delicate, incomplete capsule. Notably, pleomorphic adenomas that arise in the minor salivary glands usually lack a capsule. These tumors grow slowly, though they may become larger than other SGTs. The thin, delicate capsule may have projections into the surrounding parotid tissue. This is of particular clinical significance because obtaining clean margins and avoiding spillage are mandatory to minimize recurrence.

Microscopically, benign mixed tumors are characterized by variable, diverse, structural histologic patterns. Frequently, they have growth patterns of sheets, strands, or islands of spindle and stellate cells, with a myxoid configuration occasionally predominating. Treatment of benign neoplasms involves the complete surgical excision of the affected gland. If the parotid gland is involved, superficial parotidectomy with standard facial nerve dissection and preservation is the procedure of choice. Enucleation is contraindicated because of the tendency towards tumor spillage that can lead to tumor recurrence.

Warthin tumor

Warthin tumor (papillary cystadenoma lymphomatosum, cystic papillary adenoma, adenolymphoma) was first recognized by Albrecht in 1910 and later described by Warthin in 1929. In gross appearance, it is a smooth, soft, parotid mass. It is well encapsulated when located in the parotid gland and contains multiple cysts.

Histologically, the Warthin tumor has a heavy lymphoid stroma and aciniform epithelial cells that line the cystic areas with papillary projections. Malignant transformation has not been observed. All patients with this tumor survive, and the recurrence rate is 5%. The Warthin tumor tends to be bilateral (10% of cases) and is usually found in the major glands, as are most other types.

Intraductal papilloma

IDP is a small, tan, fairly smooth lesion that is usually found in the submucosal layer. Microscopically, IDP consists of a cystically dilated duct partially lined with a cuboidal epithelium with complex anastomosing papillary fronds of variable size filling the cystic area. IDP of the minor salivary gland is a rare lesion that has been described only in various case reports.

Histologically, the differential diagnosis of IDP includes papillary cystadenoma, which is commonly but erroneously diagnosed as IDP. In papillary cystadenoma, intraductal hyperplasia occurs and the dilated duct contains some papillary folds and projections. However, this occurs much less frequently than in IDP.

Oxyphil adenoma (oncocytoma)

Oxyphil adenoma (oncocytoma) was first described by Duplay in 1875. Oncocytomas of the salivary glands are very uncommon. Such neoplasms occur more often in women than in men, with a female-to-male ratio of 2:1. Patients are older than 50 years, and the superficial lobe of the parotid gland is the most commonly reported location. Oncocytomas rarely, if ever, occur in the minor salivary glands. They manifest as small (<5 cm in diameter), firm, slow-growing, spherical masses. Bilateral oncocytomas of the parotid glands have been described.

Histologically, oncocytomas are large and spherical and have a distinct capsule. Uniform cells are arranged in solid sheets. These tumors recur if excision is incomplete. [7]

Benign nonepithelial tumors

Hemangiomas

Hemangiomas are the most common SGTs in children and usually involve the parotid gland. Less often, they may involve the submandibular gland. These vascular tumors may be distinguished from vascular malformations by their presence early in life, rapid growth phase in children aged approximately 1-6 months, and gradual involution over 1-12 years.

The typical presentation is an asymptomatic, unilateral, compressible mass. Gross examination reveals a dark red, lobulated, unencapsulated mass. Microscopically, hemangiomas are composed of solid masses of cells and multiple anastomosing capillaries that replace the acinar structure of the gland. Because they lack a capsule, they tend to infiltrate neighboring structures.

Treatment should initially consist of steroids administered in a dosage of 2-4 mg/kg/day. Although the response may be immediate, only 40-60% of hemangiomas exhibit a response to steroids. Despite the tendency toward spontaneous involution, specific conditions may warrant surgical excision.

Lymphangioma (cystic hygroma)

Lymphangiomas are most commonly located in the head and neck region of infants and children. They are believed to be due to lymphatic sequestration of primitive embryonic lymph ducts that undergo irregular growth and canalization. They are spongy, multiloculated masses with a yellowish or bluish surface and are formed by endothelial-lined spaces. More than 50% manifest at birth, and 80% manifest by age 2 years. Usually, they manifest as painless masses that may involve parotid glands, submandibular glands, or both.

Diagnosis is made on the basis of clinical findings. Surgical excision with preservation of the vital structures is the treatment of choice. Lymphangiomas rarely cause symptoms of airway obstruction, and excision is usually for cosmetic reasons.

Lipoma

Lipomas are relatively uncommon in a major salivary gland. They derive from fat cells and appear grossly as smooth, well-demarcated, bright-yellow masses. Histologically, the tumor consists of mature adipose cells with uniform nuclei.

These tumors manifest as soft, mobile, painful masses and peak in the fifth and sixth decades of life, with a male-to-female ratio of 10:1. They are slow-growing tumors with an average diameter of 3 cm. Treatment is surgical excision.

Tumorlike lesions

Necrotizing sialometaplasia

Necrotizing sialometaplasia may easily be mistaken for a malignant tumor because it presents as a single, unilateral, painless or slightly painful lesion on the hard palate. However, it is a benign, self-healing lesion of the minor salivary glands that is seen in adults older than 40 years and is 2-3 times more common in men than in women. Although the etiology is unknown, it may represent a reparative process in response to ischemic necrosis of salivary tissue. A biopsy helps to rule out a malignant process; otherwise, no treatment is indicated.

Lymphoepithelial hyperplasia

Lymphoepithelial hyperplasia (Mikulicz disease, sicca complex, chronic punctate sialadenitis) can manifest as a diffuse enlargement of all or part of the parotid gland, or it may manifest as a discrete mass. Histologically, the lesion is composed of a diffused, well-organized lymphoid tissue and lymphocytic interstitial infiltrate with obliteration of the acinar pattern.

Lymphoepithelial hyperplasia is more frequent in females than in males, and its peak incidence is in the fourth and fifth decades of life. Occasionally, both parotid glands are involved. The growth of this tumor is slowly progressive, and it gives rise to pain around the ear or the retromandibular area.

Metastatic tumors

Of metastatic tumors of the parotid gland, 46% are melanoma, 37% are squamous cell carcinoma, and 17% are various other tumors. This diagnosis carries a poor prognosis. [8]

Previous