Salivary glands

Outline

• Anatomy.

• Physiology.

• Disorders of the salivary glands :

★ Functional disorders.

★ Inflammatory disorders

★ Neoplastic disorders.

Anatomy

• Salivary glands are apocrine glands

• Parotid gland ( the largest , serous secretions )

• Submandibular ( smaller , Serous+ mucous

secretions)

• Sublingual ( mostly mucous secretions )

• Minor salivary glands ( secrete mucous)

Physiology

• Salivary glands produce mostly the saliva.

• Secretory units in each of these glands are composed

of acinus,myoepithelial cells, intercalated duct,

striated and excretory ducts.

• The acinus contains secretory granules ( amylase in

serous producing acini and mucin in mucous producing

acini )

• 600-1200 ml of saliva is produced per day ( 45-60 %

submandibular , 30-45% parotid and 5% sublingual)

• parasympathetic stimulation produces saliva , denervation

leads to atrophy of the gland .

• Sympathetic stimulation causes scant saliva production (

more viscous and more amylase )

Salivary gland diseases

• Functional.

• Obstructive.

• Non neoplastic.

• Neoplastic

Functional disorders

• Xerostomia : ( medications, radiation, trauma ,

denervation, post surgical)

• Sialorrhea ; increase in salivary flow. ( mental

retardation , mercury poisoning, medications ,

psychological , Rabies )

• Mucoceles and ranulas ( sublingual mucocele at the

floor of the mouth) treated with excision. usually

secondary to trauma , mostly lower lip.

Obstructive disorders

• Sialolithiasis ( stones )

• Can occur in either the parotid or the submandibular

gland ( more common in SMG due to longer duct ,

more viscous secretions , higher Ca and PO4

contents )

• Obstruction causes swelling and acute pain, usually

resolves after a while.

• Intermittent swelling and pain.

• Diagnosis through sialogram.

• Treatment is by intra-oral sialolithotomy or external

Sialadenectomy.

Inflammatory disorders

• Infectious :

✴Viral ( mumps parotitis )

✴Bacterial

✴Acute bacterial ; elderly dehydrated patients , S.

Aureus , might need I&D if they develop an abscess in

addition to Abx.

• Physical examination shows purulent discharge from

the duct opening upon milking it.

• Diagnosis is based on H&P.

Neoplastic disorders

• Neoplastic lesions of the salivary glands are rare (

2/100,000 in the US ) making about 1% of head and

neck tumors.

• 80% i n the parotid gland , 10-15% arise from the

submandibular gland.

• Parotid tumors are more likely to be benign , the

smaller the gland the higher the risk of the tumor

being malignant ( almost half of the submandibular

and the majority of sublingual gland tumors )

Benign Tumors

• Pleomorphic Adenoma.

• Papillary Cystadenoma Lymphomatosum

(Warthins Tumor)

• Basal Cell Adenomas.

• Oncocytoma

Pleomorphic adenoma • In 90% of the cases the tumors affects the parotid gland,

most often present in lower pole of superficial lobe of the

gland.

• Females > males between 4-6 decade.

• Clinical features:

• Slowly growing , painless, solitary , firm, smooth and

mobile mass.

• No facial nerve paralysis.

• CT scan and U/S are helpful imaging modalities.

• FNA for diagnosis

• Surgical excision is the treatment of choice ( superficial

Parotidectomy)

• XRT may be a useful therapy for this type of tumor due to

high recurrence rate and ability to degenerate into

malignant.

Warthin’s tumor

• Mainly in parotid

• Over 60 years of age

• Male to female 5:1 ratio.

• Bilateral in 6%-12% of patients.

• Painless lesion unless secondarily infected.

• Treatment is mostly by surgical excision, no malignant

potential.

Malignant Tumors

• Mucoepidermoid Carcinoma ( most common

malignant tumor of the salivary glands )

• Adenoid Cystic Carcinoma

• Important features to look for in the H&P ;

• facial nerve paralysis.

Mucoepidermoid carcinoma

• Most common malignant tumor of the salivary gland

mostly affecting the parotid gland (5% of salivary

gland tumor).

• Affects minor salivary gland in 15% of these cases.

• Seen in the age group of 40-50 years with female

predilection.

• Low grade or high grade depending on the ratio of

epidermal cells to mucous cells.

• 75% low grade and have good prognosis, they rarely

spread or metastasize.

• High grade tumors can spread locally or metastasize

distally ( both lymphatic and hematogenous spread).

• Treatment is the surgical excision of the tumor with

post operative radiotherapy.