Neoplasms of salivary glands

Dr. Ramesh Parajuli, MSChitwan Medical College Teaching Hospital,

Chitwan, Nepal

• Major salivary glands: paired1.Parotid2.Submandibular3.Sublingual

• Minor salivary glands: multiple, submucosal, upper aerodigestive tract eg. from nasal cavity and lips down to the esophagus and trachea

Salivary gland anatomy

Salivary gland microanatomy

Neoplams of salivary glands• Tumors of salivary glands –

uncommon

• 3% to 6% of all tumors of head & neck region

• Proportion of malignant and benign varies with gland of origin

• Larger the size of salivary gland, more the chance of tumor being benign

• Distribution

– Parotid: 80% overall; 80% benign (80% pleomorphic adeoma) i.e. “Rule of 80”

– Submandibular: 15% overall; 50% benign

– Sublingual/Minor salivary gland: 5% overall; 40% benign

• Incidence of malignancy is higher in neoplasm of minor salivary glands. i.e.

Parotid- 25% Submandibular- 50% Minor salivary gland- 75%

Risk factors for salivary neoplasms

• Low dose radiation exposure

• Wood dust

• Chemicals (leather tanning industry)

• Rubber industry

• Nickel compound/alloy

Benign tumors• Pleomorphic adenoma

• Warthin’s tumor

• Oncocytoma

• Lymphangioma

• Haemangioma

Pleomorphic adenoma(mixed tumor)

• Mixed tumor: contains both epithelial and mesenchymal elements

• Most common benign tumor of salivary glands

• Can arise from parotid, submandibular

• Parotid: usually arises from its tail, deep lobe

• Encapsulated• Slow growing tumor

• Signs: Swelling in front, below & behind ear Raises ear lobule Retromandibular groove is obliterated

• Any swelling which raises ear lobule is due to parotid gland neoplasm unless proved otherwise

• It sends ‘pseudopods’ into surrounding gland surgical excision of the tumor should include normal tissue around it

• Superficial parotidectomy

Oncocytoma (oxyphil adenoma)

• Rare: 2.3% of benign salivary tumors

• 6th decade

• Usually benign; malignant oncocytoma- less common• • Major salivary glands: Parotid,Submandibular gland

• Minor salivary glands: palate, buccal mucosa, tongue

• Superficial parotidectomy

Warthin’s tumor(adenolymphoma)• Encapsulated • Exclusively in parotid gland• Parotid tail• Commonly seen btw 5th – 7th

decade• Male: female (7:1)• About 7% of salivary gland

tumor• Usually Fluctuant, slow growing• 10% bilateral• Histologically: epithelial &

lymphoid elements• Never malignant• Wide local excision

Hemangioma & lymphangioma

• Haemangioma: Most common benign tumors of the parotid in children

• May involute spontaneously• Soft, painless and increase in size with crying

or straining • Surgical excision if do not regress • Lymphangioma:• Less common• Soft, cystic on palpation• Do not regress spontaneously surgical

excision

Malignant neoplasms• Mucoepidermoid carcinoma

• Adenoid cystic carcinoma

• Carinoma ex- pleomorphic adenoma

• Adenocarcinoma

• Squamous cell carcinoma

• Non-hodgkin’s lymphoma

Mucoepidermoid carcinoma• Most common salivary gland malignancy • Not encapsulated• Commonly in parotid glandClinical features:Slow growingFacial nerve palsyPresentation Low-grade: Slow growing, painless mass High-grade: Rapidly enlarging, +/- pain

Treatment: Total conservative parotidectomy

Adenoid cystic carcinoma(Cylindroma)• 2nd most common salivary gland

malignancy• Slow growing• Infiltrates widely into the tissue

planes & muscles• Perineural spread• Commonly in submandibular

gland, sublingual or minor salivary glands

• Less commonly in parotid gland• Occasionally lymph node

metastasis• Local recurrence after surgical

excision(perineural and lymphatic spread)

Treatment• Radical parotidectomy

• Post-operative radiotherapy

• Wide local excision of palate: for tumors of palate

Adenoid Cystic Carcinoma of right hard palate

Carcinoma ex-pleomorphic adenoma• Usually from pre-

existing pleomorphic adenoma (only 1% arise ab-initio)

• Malignancy takes about 10 years to develop in an adenoma

• Malignancy should be suspected when:- -Rapid growth -Facial nerve palsy -Painful -Skin infiltration -Get fixed to massester muscletrismus -Feels stony hard -Presence of lymph nodes in neck

Adenocarcinoma & Squamous cell carcinoma

• Rare• Highly aggressive • Rapidly growing tumors• Local and distant metastases• Prognosis- very poor

• Squamous cell ca (SCC): Rule out metastasis in the parotid gland from neighbouring skin cancer or other head and neck tumor

Parotid gland surgery

Landmarks for facial nerve during parotid surgery

1.Tympano-mastoid suture: 6-8 mm deep to this suture

2.Groove between mastoid & bony EAC: bisected by facial nerve

3.Tragal pointer: 1 cm anteroinfero-medial is facial nerve

3.Styloid process: lateral lies facial nerve

4.Posterior belly of digastric: superior & parallel lies facial nerve

Complications of parotid surgery (5 F’s)1. Flap necrosis: avoid acute bending(angle) of the

incision & use gentle retraction

2. Facial nerve palsy: nerve identification

3. Fluid collection: blood or seromadrain should be kept

4. Fistula (salivary): duct should be ligated

5. Frey’s syndrome (gustatory sweating): in 10% cases

Frey’s syndrome• Several months after parotid surgery• Sweating and flushing of the preauricular skin during

mastication• Auriculotemporal nerve provides both -Parasympathetic innervation to Parotid gland-Sympathetic innervation to Sweat glands & Subcutaneous

blood vesselsNeurotransmitter to both fibers: Acetylcholine

Frey’s syndrome is due to regrowth of parasympathetic secretomotor fibers into distal cut ends of the sympathetic fibers of skin

Whenever patients eats reflex salivation occurs, the skin blood vessels dilate and sweat gland secretes

Management: Reassurance

Aluminium chloride-antiperspirant, useful astringent

Anticholenergics-topical eg glycopyrolate

Botulinum toxin A- injection into affected skin

Surgical: Tympanic neurectomy: dennervation

Submandibular gland excision

Nerves likely to be injured during SMG excision:-

1. Marginal mandibular nerve

2. Lingual nerve

3. Hypoglossal nerve

Thank you