Diseases of salivary glands

Diseases of Salivary Glands

Dr Maitham H. Kenber

Parotid

gland

Submandibular

gland

Sublingual

gland
Salivary Glands Overview

• Major salivary glands

• a. Parotid gland
• b. Submandibular gland
• c. Sublingual gland
• 2. Minor salivary glands
• 600 – 1,000 minor salivary gland distributed throughout the mucosa of the upper aerodigestive tract (more common in the soft and hard palate).
•
Salivary glands


Minor glands
Minor salivary glands are not found within gingiva and anterior part of the hard palate

Major salivary glands

Parotid: watery serous saliva rich in amylase, proline-rich proteins
Stenson’s duct
Submandibular gland: more mucinous
Wharton’s duct
Sublingual: viscous saliva
ducts of Rivinus;

Parotid gland

Located in the preauricular region and along the posterior surface of the mandible .
Parotid gland is divided by the facial nerve into :
* superficial lobe overlying the lateral surface of the masseter
* deep lobe between the mastoid process of the temporal bone and the ramus of the mandible

Parotid duct

Submandibular gland

Lies in digastric (submandibular) triangle
Devided by mylohyoid muscle into
1.superficial lobe
2.deep lobe
Duct of submandibular (Wharton’s duct) from deep lobe pass between hyoglossus and mylohyoid m. to open at sublingual caruncle in the floor of the mouth lateral frenulum of the tongue

Sublingual gland

Sublingual caruncle

Sublingual Salivary glands

Smallest of the major salivary glands.
Almond shape
Deep to the floor
of mouth mucosa.
It is drained by approximately
10 small ducts (Ducts of Rivinus)

Functions

Protection
lubricant (glycoprotein)
barrier against noxious stimuli; microbial toxins and minor traumas
washing non-adherent and acellular debris
formation of salivary pellicle
calcium-binding proteins: tooth protection; plaque


Functions cont’d
Buffering (phosphate ions and bicarbonate)
bacteria require specific pH conditions
plaque microorganisms produce acids from sugars

Functions cont’d

Digestion
neutralizes esophageal contents
dilutes gastric chyme
forms food bolus
brakes starch

Functions cont’d

Antimicrobial
lysozyme hydrolyzes cell walls of some bacteria
lactoferrin binds free iron and deprives bacteria of this essential element
IgA agglutinates microorganisms

Functions cont’d

Maintenance of tooth integrity
calcium and phosphate ions
ionic exchange with tooth surface


Functions cont’d
Tissue repair
bleeding time of oral tissues shorter than other tissues
resulting clot less solid than normal
remineralization

Functions cont’d

Taste
solubilizing of food substances that can be sensed by receptors
trophic effect on receptors

Salivary Gland Diseases

Functional disorders

Obstructive disorders

Infectious disorders

Neoplastic disorders

Functional Disorders of the Salivary Glands

Functional Disorders of the Salivary Glands cont’d
Sialorrhea (Increased flow of saliva)

(i) Psychosis

(ii) mental retardation
(iii) certain neurological diseases
(iv) rabies
( v) mercery poisoning

Functional Disorders of the Salivary Glands cont’d

• Xerostomia (Dry mouth)
• ↓ flow of saliva
• Mumps,
• Sarcoidosis
• Sjoegrens syndrome
• Lupus
• post-irradiation treatment


Functional Disorders of the Salivary cont’d Glands (Sjogren’s Syndrome)

Triad of dry eyes, dry mouth, dry joints

Autoimmune disorder

Lymphocytic infiltration of the salivary glands.

Functional Disorders of the Salivary Glands cont’d
Mucocele
Secondary to trauma
70% occur in lower lip
Excisional biopsy usually curative

Functional Disorders of the Salivary Glands cont’d

Ranula


Sublingual salivary gland mucocele

Treatment should include removal of Sublingual gland

Obstructive Disorders of the Salivary Glands

Obstructive Disorders of the Salivary Glands
Obstruction to the flow of saliva via the salivary duct can occur due to the presence of salivary gland stone (Sialolith).

Obstruction can also secondary to the stricture (Narrowing) of the salivary gland duct.

Obstructive Disorders of the Salivary Glands cont’d

Sialolithiasis (Salivary gland stone)

93% occur in submandibular gland
7% in parotid gland
Multiple occurrence in same gland is common


Sialolithiasis (calculi) cont’d
Associated with Chronic sialoadenitis
Male > female , 50-80 years of age
submandibular gland affected far more common than parotid gland
Composed of Calcium , phosphate and carbonate , combined with other salts (Mg,Zn,NH3) and organic material

Factor predisposing to calculi in SMSG

Submandibular saliva
1.high mucin content
2.alkaline pH
3.high phosphate & calcium
Sialolithiasis (calculi) cont’d

Sialolithiasis (calculi) cont’d

Factor predisposing to calculi in SMSG cont’d
Anatomy
1.length and irregular course of Wharton’s duct
2.position of ductal orifice
3.size of orifice smaller than duct lumen

• Symptoms

• colicky postprandial pain and swelling
• Local swelling & tenderness at ductal opening if the stone is superficial
• Secondary infection – predispose to duct stricture
Sialolithiasis (calculi) cont’d


Submandibular Gland - Sialolithiasis
Diagnosis
Pain and sudden enlargement of gland while eating
Palpation of stone in the submandibular duct
Occlusal radiograph (80%)
Sialogram

Submandibular Gland - Sialolithiasis

Submandibular Gland – Sialolithiasis cont’d
Treatment
Stone can be removed transorally if in the duct and easily palpable

Submandibular Gland – Sialolithiasis cont’d

Treatment

If the stone is inside the gland and therefore damaging the gland, then the whole gland should be removed under G.A.

Parotid Gland - Sialolithiasis

Diagnosis
Based on history
Swelling during meals
Bimanual palpation of painful gland
40% non-radiopaque
Most parotid stones are multiple
Sialogram


Parotid Gland - Sialolithiasis
Treatment
Stones in extraglandular portion of duct can be removed transorally
Intraglandular stones removed from extraoral
approach by Superficial Parotidectomy.

Sialogram

A sialogram is a dye investigation of a salivary gland. It is carried out to look in detail at the larger salivary glands, namely the parotid or submandibular glands.

Infectious Disorders of the Salivary Glands

Acute Sialadenitis - Infectious
Etiology

Viral - ( Mumps)

Bacterial

Viral- Acute Sialadenitis (Mumps)

Acute painful parotitis

Viral in etiology

Self limiting

Mumps

Complications
Orchitis/oophritis
Meningitis / encephalitis
Pancreatitis
Deafness
Arithritis

Bacterial - Acute Sialadenitis

Signs and symptoms


Swelling, xerostomia, failure of secretion with ascending infection
(Staph aureus, Strep pyogenes, most common infective organism)

Painful swelling parotid gland, overlying skin red, shiny & tense, pus from parotid duct
(if involving the parotid gland)

Bacterial - Acute Sialadenitis

Treatment

Culture pus for Sensitivity

Prescribe appropriate antibiotic

Supportive therapy

Fluids
Hot pads
Salivary stimulants

Necrotizing Sialometaplasia

Benign inflammatory condition
Usually involves the minor salivary gland of hard palate
Will often simulate a malignant condition
No definite etiology
1-3 cm ulcer heals spontaneously

Bilateral

Midline

in location

Neoplastic Disorders of the Salivary Glands

80% of salivary gland tumor occur in the parotid.
5 – 10% in the submandibular gland.
10 – 15% in the minor salivary gland.

80% of the parotid tumor are benign.

The most common is pleomorphic adenoma.
50% of the submandibular gland tumor are benign.
30% of the minor salivary gland are benign.
Salivary Gland Tumors


Benign Salivary Gland Tumors
Adenomas (Epithelial)

Pleomorphic adenoma

Monomorphic adenoma

Adenolymphoma

Oxyphilic adenoma

Other types

Pleomorphic Adenoma (Mixed Tumor)

Commonest tumour ( 53% - 71% ) of the salivary glands

Tumor is slow growing, painless, solitary, firm, smooth, moveable without nerve involvement

Both mesenchymal / epithelial elements

Investigations include FNA, CT, MRI

Pleomorphic adenoma cont’d

Epithelial Components
Tubular and cord-like arrangements
Cells contain a moderate amount of cytoplasm
Mitoses are rare
Stromal or “mesenchymal” Components
Can be quite variable
Attributable to the myoepithelial cells
Most tumors show chondroid (cartilaginous) differentiation
Osseous metaplasia not uncommon
Relatively hypocellular and composed of pale blue to slightly eosinophilic tissue.








Management
Superficial parotidectomy
total parotidectomy if deep lobe involvement
Recurrent rate 5% with superficial parotidectomy
Chance of turn to malignancy 3-10%
Pleomorphic adenoma cont’d

Monomorphic Adenoma

Similar to Pleomorphic Adenoma except no mesenchymal stromal component
Predominantly an epithelial component
More common in minor salivary glands (upper lip)
Rare malignant potential
Types:
Basal Cell Adenoma
Canicular Adenoma
Myoepithelioma Adenoma
Clear Cell Adenoma
Membranous Adenoma
Glycogen-Rich Adenoma

Warthin’s Tumor

Warthin’s tumour is also called as papillary cystadenoma lymphomatosum
6% - 10% of all parotid tumors
Benign , affects parotid gland only
bilateral ( 10% )
Older age group
Superficial location, therefore in most cases Superficial parotidectomy is performed.
Both lymphoid and oncocytic epithelial elements must be present to diagnose Warthin’s
Malignant potential not existed

Malignant Tumours of the Salivary Glands

Locally aggressive in nature

Some grow along neural pathways, may access skull base and brain eventually

Also lymphatic and haematogenous spread

Incidence of Salivary Gland Malignancy According to Site

Sublingual 70%


Submandibular 40%

Parotid 20 %

A useful rule of thumb is the 25/50/75 rule. That is, as the size of the gland decreases, the incidence of malignancy of a tumor in the gland increases in approximately these proportions.

Salivary Gland Tumors

Features suggestive of malignancy
Induration
Fixed overlying skin or mucosa
Ulceration of skin or mucosa
Rapid growth
Short duration
Pain often severe
Facial nerve palsy

Malignant neoplasm

Mucoepidermoid carcinoma
Adenoid cystic carcinoma
Acinic cell carcinoma
adeno carcinoma
Carcinoma Ex. Pleomorphic adenoma or malignant mixed tumor
Squamous cell carcinoma
Undifferentiated carcinoma
miscellaneous


Mucoepidermoid Carcinoma
Mucoepidermoid carcinoma (MEC) is the most common malignant tumor of the parotid gland and the second-most common malignancy (adenoid cystic carcinoma is more common) of the submandibular and minor salivary glands.
MECs constitute approximately 35% of salivary gland malignancy, and 80% of MECs occur in the parotid gland.

Mucoepidermoid tumor

MECs contain two major elements:
mucin-producing cells and epithelial cells of the epidermoid variety
75% are low grade & have good prognosis
5 year survival 85%

High grade mucoepidermoid carcinomas invade locally, spread regionally with distant metastasis.
5 year survival drops 30%

Carcinoma in pleomorphic adenoma

Mixed malignant tumour
Long standing pleomorphic adenoma
Older age group
Worse prognosis
Lymph node metastases 15%
Distant metastases 30%
5 year survival 40% - 50%
15% year survival 20%


Adenoid cystic carcinoma (cylindroma)
2nd most common malignant
ACC is the most common malignant tumor found in the submandibular, sublingual, and minor salivary glands.
Age : 40-60 yrs
Peri-neural invasion
30% lymph node metastasis,
50% distant metastasis
- 5 year survival 75%
- 10 year survival 30%
- 20 year survival 13%

Adenoid cystic carcinoma

Acinic cell carcinoma
2-4 % of all salivary gland tumors
Most common at parotid gland
Age 30-60 yrs
Characteristic
Bilateral ( 3%)
Well defined border
Hematogenous spreading to lung, spine
Gross : no capsule but clear border
Management
Surgical with facial nerve conservation
Low recurrent rate


Acinic cell carcinoma

Acinic cell carcinoma

adenocarcinoma

Minor salivary > parotid gland
Men 30-60 yr
Most severe
High recurrence rate
Metastasis is common
Management
Total parotidectomy ( if in parotid) & resection some part of facial nerve & cervical lymph node dissection

Squamous cell carcinoma of Salivary glands

Infrequent occurrence 1% - 5%


May have skin infiltration

Total radical parotidectomy

Evaluation & Diagnosis of Malignant Salivary gland Tumors
History & clinical examination, use TNM Classification to stage the cancer
Sialography – of no value
CT scans and MRI
CT sialography for retromandibular / parapharayngeal lesions
Incisional biopsy is contraindicated
FNAC

74
Investigations
FNAC >90% specificity, sensitivity
MR =ideal for deep lobe
MR Angiography
CT-3D sialography
99 m Tc scan for Warthin’s

75
MR>CT
Tumor-salivary gland interface
Benign Vs malignant
7 n or Perineural evaluation
Intracranial extension of tumor
DD; Parapharyngeal tumors
DD; Neurogenic tumors


76
CT>MR for bone erosion
CE-CT is better than non CE
Base of skull involvement
Mandible erosion

77
T
T1 <2 cm
T2 >2-4 cm
T3 >4-6 cm
T4 >6 cm

78
N
No no lymph node metastasis
N1 <3 cm,ipsilateral single
N2 A >3-6 cm,ipsilateral single
B <6cm,ipsilateral multiple
C <6cm, bilateral
N3 >6 cm


79
M
Mo -ve distant mets
M1 +ve distant mets

80
M
Lung
40% Adenoid Cystic
30% Malignant Mixed
Also with Acinic cell
SM:P::2:1

81
Mode of Spread
Expansion
Local infiltration
Lymphatics
Perineural infiltration
Seedling locally and in the skin


Indication for postoperative radiation therapy salivary malignancy
High-grade tumors
Squamous cell carcinoma
Malignant mixed tumors
Adenocarcinoma
High-grade mucoepidermoid carcinoma
Close or positive margins
Facial nerve involvement

Indication for postoperative radiation therapy salivary malignanncy

Perineural spread
Bone/connective tissue involvement
Lymph node metastasis
Extranodal extension
Recurrent diseases





























True or false

More than 70% of malignant tumors of salivary glands occur in the parotid