Diseases of Salivary Glands Dr Maitham H. Kenber

Salivary Glands Overview Parotid gland Sublingual gland Submandibular gland

Salivary glands 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).

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 Devided by mylohyoid muscle into 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 caruncle Sublingual gland

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

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

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

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

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

Salivary Gland Tumors 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.

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.

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

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

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

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

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

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

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

M Mo -ve distant mets M1 +ve distant mets

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

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