Accessory parotid gland

Changed by Daniel J Bell, 31 Dec 2017

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Accessory parotid glands are a normal variant and represent ectopic salivary tissue separate from, but usually in close proximity to, the main parotid glands ¹. Occasionally the accessory tissue is contiguous with the main glands.

Epidemiology

Accessory parotid glands are commonly picked up incidentally on ultrasound; seen in ~20% of the general population ².

Gross anatomy

Located on the lateral aspect of the masseter muscle, anterior to the main parotid gland, usually superior (occasionally anterior) to the main parotid duct (Stensen duct) ^{2, 3,3}.

Accessory parotid glands have their own blood supply and secondary duct emptying into the main parotid duct ⁴.

Radiographic features

Accessory parotid glands have the same US echotexture, CT density and MRI signal as the main parotid glands.

Related pathology

Any disorder that affects the main parotid gland may also affect the accessory parotid tissue, but tumours of the accessory parotid glands are rare ^5, 6,6.

-<p><strong>Accessory parotid glands </strong>are a normal variant and represent ectopic salivary tissue separate from, but usually in close proximity to, the <a href="/articles/parotid-gland">main parotid glands</a> <sup>1</sup>. Occasionally the accessory tissue is contiguous with the main glands.</p><h4>Epidemiology</h4><p>Accessory parotid glands are commonly picked up incidentally on ultrasound; seen in ~20% of the general population <sup>2</sup>.</p><h4>Gross anatomy</h4><p>Located on the lateral aspect of the <a href="/articles/masseter-muscle">masseter muscle</a>, anterior to the main parotid gland, usually superior (occasionally anterior) to the <a href="/articles/parotid-duct">main parotid duct</a> (Stensen duct) <sup>2, 3</sup>.</p><p>Accessory parotid glands have their own blood supply and secondary duct emptying into the main parotid duct <sup>4</sup>.</p><h4>Radiographic features</h4><p>Accessory parotid glands have the same US echotexture, CT density and MRI signal as the main parotid glands.</p><h4>Related pathology</h4><p>Any disorder that affects the main parotid gland may also affect the accessory parotid tissue, but tumours of the accessory parotid glands are rare <sup>5, 6</sup>.</p>
+<p><strong>Accessory parotid glands </strong>are a normal variant and represent ectopic salivary tissue separate from, but usually in close proximity to, the <a href="/articles/parotid-gland">main parotid glands</a> <sup>1</sup>. Occasionally the accessory tissue is contiguous with the main glands.</p><h4>Epidemiology</h4><p>Accessory parotid glands are commonly picked up incidentally on ultrasound; seen in ~20% of the general population <sup>2</sup>.</p><h4>Gross anatomy</h4><p>Located on the lateral aspect of the <a href="/articles/masseter-muscle">masseter muscle</a>, anterior to the main parotid gland, usually superior (occasionally anterior) to the <a href="/articles/parotid-duct">main parotid duct</a> (Stensen duct) <sup>2,3</sup>.</p><p>Accessory parotid glands have their own blood supply and secondary duct emptying into the main parotid duct <sup>4</sup>.</p><h4>Radiographic features</h4><p>Accessory parotid glands have the same US echotexture, CT density and MRI signal as the main parotid glands.</p><h4>Related pathology</h4><p>Any disorder that affects the main parotid gland may also affect the accessory parotid tissue, but tumours of the accessory parotid glands are rare <sup>5,6</sup>.</p>

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