Parotid gland

Dr Dan J Bell and Dr Jeremy Jones et al.

The parotid gland is the largest of the salivary glands and secretes saliva via the parotid duct into the oral cavity to facilitate mastication and swallowing. It is located in the parotid space

The parotid gland is wrapped around the mandibular ramus and extends to a position anterior and inferior to the ear within the parotid space. The facial nerve and its branches pass through the parotid gland, as does the external carotid artery (ECA) and retromandibular vein. The ECA forms its two terminal branches within the parotid gland: maxillary and superficial temporal artery. There is moderate fatty infiltration or fatty replacement of the parotid glands with age 6.

The gland usually contains several intraparotid lymph nodes. These are typically situated in two locations within the gland: pre-trial (pre-auricular) and in the apex of the superficial lobe. These lymph nodes are the first station of lymphatic drainage of the skin of the pinna and peri-auricular skin.

There is a fibrous capsule surrounding the gland, formed by the split layers of the investing layer of the deep cervical fascia. Posteriorly this fascia condenses forming the stylomandibular ligament. The inferior projection of the parotid is often referred to as the "tail" which overlies the angle of the mandible. Anteriorly there is often an accessory parotid gland which may be separate to the main gland.

Blood supply

Arterial supply is gained from the ECA and a specific branch of the artery, the transverse facial artery. Venous drainage is via a plexus of veins into the internal jugular vein.

Ultrasound
  • appears homogeneous with increased echogenicity compared to nearby muscle 1
  • intraparotid lymph nodes are normally seen (unlike the submandibular gland)
  • retromandibular vein and external carotid artery are also easily seen and by inference the facial nerve, which lies lateral to these vessels 1
  • ​ultrasound is often the first diagnostic procedure to evaluate morphological and structural changes of the parotid gland; for small (<3 cm) and superficial lesions, ultrasound and cytology are often sufficient for a definitive diagnosis 2
  • neoplasms of the parotid are solid and often hypoechoic 

  • limitations of ultrasound are:

    • difficulty visualising deep lesions: the deep lobe is not able to be assessed as it is protected by the mandibular ramus

    • difficulty visualising deep extension: associated extension of the mass into parapharyngeal, retropharyngeal spaces, deep cervical lymph chain, and the base of skull 3

CT/MRI
  • CT and MRI provide useful additional diagnostic imaging if a malignancy is suspected 4
  • the sensitivity of CT/MRI approaches 100% for detecting parotid neoplasms 5
Head and neck anatomy
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Article information

rID: 10448
System: Head & Neck
Section: Anatomy
Synonyms or Alternate Spellings:
  • Parotid glands
  • Parotid salivary gland
  • Parotids
  • Parotid salivary glands

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    Parotid position
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