Description.

the most common tumor of the salivary glands overall, it accounts for about 60% of all salivary gland tumors. It is often called

a mixed tumor because it consists of both epithelial and

mesenchymal elements.

The majority of these tumors are found in the parotid glands, with less than 10% in the submandibular,

sublingual, and minor salivary glands

Pleomorphic adenomas may occur at any age, but the highest incidence is in the fourth to sixth decades of life. It also represents the most common salivary neoplasm in children.

Clinical Presentation.

These tumors appear as painless,

firm, and mobile masses that rarely

ulcerate the overlying skin or

mucosa

In the parotid gland

these neoplasms are slow

growing and usually occur in the

posterior inferior aspect of the superficial lobe

In the submandibular glands

they present as well-defined

palpable masses

It is difficult to distinguishthese tumors from malignant

neoplasms and indurated lymph

nodes Intraorally

pleomorphic adenomas most often

occur on the palate, followed by the

upper lip and buccal mucosa.

Pleomorphic adenomas can vary in

size, depending on the gland in which

they are located.

In the parotid gland, the tumors are

usually several centimeters in diameter

but can reach much larger sizes if left

untreated

. When observed in situ, the tumors

are encased in a pseudocapsule and

exhibit a lobulated appearance

Pathology.

The gross appearance of pleomorphic

adenoma is that of a firm smooth mass within a pseudocapsule.

Histologically, the lesion demonstrates both epithelial and

mesenchymal elements. The epithelial cells

make up a trabecular pattern that is

contained within a stroma.

The stroma may be chondroid, myxoid,

osteoid, or fibroid. The presence of these different elements accounts for the name

pleomorphic tumor or mixed

One characteristic of a pleomorphic

adenoma is the presence of microscopic

projections of tumor outside of the capsule.

Treatment.

1-SURGICAL REMOVAL WITH ADEQUATE MARGINS IS THE PRINCIPAL TREATMENT.

Because of its microscopic projections

2-this tumor requires a wide resection

to avoid recurrence

3-In spite of the capsule, close excision

should not be attempted

4-A superficial parotidectomy is

sufficient for the majority of these

lesions. A small tumor in the tail of the

parotid gland may be

removed with a wide margin of normal

tissue sparing the remainder of the

superficial lobe

5-lesions that occur in the

submandibular gland are treated by

the removal of the entire gland.

Choice of imaging modality for pleomorphic adenoma

Computed tomography (CT) is one

of the primary imaging modalities used

to assess tumors of the salivary glands.

It allows the detection of lesions and

assessment

of their extension and characteristics as

well as their relationships to nearby

structures

However, this technique has some

limitations, and higher accuracy levels

might be obtained through magnetic

resonance imaging (MRI).

Pleomorphic adenoma of the left parotid gland with a round,

painless, rubber-like swelling over the left ramus region below

the ear, covering the lower border of the mandible near the

angle

Axial computed tomography scan (encircled area enlarged) showing, (a) well-defined, hypodense, heterogeneous mass in the left parotid gland (white arrow) with poorly defined anteromedial margin (black arrow); (b) variable areas of low attenuation seen on the posterior aspect of the superficial lobe (white arrow)

CT image shows a lobular mass in the

left parotid gland.

The circumscribed borders and

location are highly suggestive of

pleomorphic adenoma, which was

confirmed with fine-needle aspiration.

Axial magnetic resonance imaging showing, (a) a well-defined hypointense mass with low signal intensity foci in the lower pole of the left parotid gland (white arrow) on T1 image (b) a heterogeneously hyperintense mass with a star-like low signal foci in the center (white arrow) and a hyperintense foci in the lower pole of the left parotid gland (black arrow) on T2 images

Axial contrast-enhanced CT scan demonstrates a poorly

enhancing mass (pleomorphic adenoma) involving the left

submandibular gland. The mass is smoothly marginated and

causes the gland to expand