Salivary Gland Tumours Notes

Salivary Glands

• There are three pairs of salivary glands— parotid, submandibular and sublingual. In addition to these, there are multiple minor salivary glands located in the cheek mucosa, lips, palate, base of the tongue, etc.
• The parotid, the “big brother of 3”, suffers mainly from 3 diseases — infection, enlargement and tumour.

Read And Learn More: Clinical Medicine And Surgery Notes

• The submandibular salivary gland suffers from mainly 2 diseases — sialadenitis and tumours. Other salivary glands are of minor importance.
• However, it should be remembered that the commonest tumour of minor salivary glands is malignancy

Parotid Gland Surgical Anatomy Of The Parotid Gland

The parotid gland is present on the lateral aspect of the face, divided by the facial nerve into the superficial lobe and deep lobe.

The superficial lobe overlies the masseter and the mandible. The deep lobe is wedged between the mastoid process and the styloid process, the ramus of the mandible and the medial pterygoid muscle.

• The superficial lobe also receives a duct from the accessory lobe which is in the region of the zygomatic arch/zygomatic process.
• The duct of the parotid, Stensen’s duct, 2–3 mm in diameter, receives tributaries from superficial, deep and accessory lobes, passes through the buccinator muscle and opens in the mucosa of the cheek opposite the upper 2nd molar tooth.
• The parotid gland is covered by a true capsule which is a condensation of the fibrous stroma of the gland, a false capsule and parotid fascia which is a part of the deep cervical fascia.

Facial Nerve

After emerging from the stylomastoid foramen, it hooks around the condyle of the mandible, enters the substance of the parotid and divides into 2 major branches, zygomaticotemporal and cervicofacial.

The facial nerve along with the retro-mandibular vein (which is formed by a branch from the superficial temporal vein joining with branches from the pterygoid plexus of veins) is present in this plane. This plane is called the fasciovenous plane of Patey.

Then the facial nerve gives rise to 5 branches which are interconnected like the foot of a goose, called Pes Anserinus. Following are the branches of the facial nerve in the face and the muscles supplied by these nerves

Acute Parotitis

Acute inflammation of the parotid can occur due to bacterial or non-bacterial causes. It can be unilateral or bilateral.

Acute Parotitis Causes

• Mumps parotitis: Mumps¹ is an acute generalised viral disease with painful enlargement of salivary glands, chiefly the parotids.
• The virus belongs to the Paramyxoviridae family and only one serotype is known.
• The disease spreads from a human reservoir by direct contact, airborne droplets or fomites contaminated by saliva and possibly by urine.
• ¹Mumps can cause parotitis, pancreatitis and orchitis

Causes Of Acute Parotitis

1. Viral: Mumps—Most common Coxsackie A & B Parainfluenza 1 & 3 ECHO Lymphocytic Choriomeningitis
2. Bacterial: Usually ascending infection Staphylococcus aureus
3. Recurrent parotitis of childhood: Recurrent, mistaken for mumps, resolves at puberty
4. Specific infections: Mycobacterial cat-scratch disease, syphilis, toxoplasmosis
5. Allergic: Food and drugs
6. Sexual diseases: HIV-related ↑ incidence
7. Post-irradiation: Reduction in the salivary juice
8. Post-operative: Due to dehydration

Clinical manifestation

The incubation period is 10–24 days. Fever, headache, and muscular pain are usually found. Both parotids are enlarged with pain and temperature. The swelling starts subsiding in 3–7 days of time.

Clinical manifestation Treatment

If symptomatic maintenance of good oral hygiene and hydration is useful. Antibiotics may be given to prevent secondary infection. One episode of infection confers lifelong immunity.

Acute bacterial parotitis Staphylococcus aureus infection of parotid produces serious illness with marked engorgement of the parotid. Typically, it produces parotid abscesses. Diabetes, malignancy and malnutrition increase the risk. Decreased salivary secretion is an important predisposing factor.

Reduction in salivary juice can occur due to various factors mentioned in the box. Postoperative parotitis can be prevented by good mouth care and good oral hygiene. Due to poor oral hygiene, ascending infection occurs from the oral cavity resulting in parotitis.

Acute Parotitis Clinical features

• A patient who is recovering in the postoperative period may complain of pain and swelling in the parotid region.
• The presence of severe pain, very sick, toxic look and high-grade fever with chills and rigours, indicates a parotid abscess. Diffuse brawny swelling is characteristic.

Causes Of Salivary Flow

• Postoperative
• Poor oral hygiene
• Dehydration
• Enteric fever, septicaemia
• Post-radiotherapy, for oral cancer

Swellings Wherein One Should Not Wait For Fluctuation

• Parotid abscess
• Breast abscess
• Ischiorectal abscess
• Pulp space infection
• Any deep-seated abscess

The swelling is due to inflammation of the parotid and since it is enclosed by parotid fascia, the swelling takes the shape of the parotid gland.

However, it is not common for a parotid abscess to raise the ear lobule. For the reason mentioned above, fluctuation is a late feature. If the abscess is not drained, it is likely to rupture into the external auditory canal.

The opening of the parotid duct may be inflamed and on gentle compression of the parotid gland, pus can be seen coming out of the parotid duct.

A conservative line of management Treatment

1. A conservative line of management is indicated in a stage of cellulitis with no evidence of abscess.

• Maintaining good hydration of the patient in the postoperative period.
• Improvement in oral hygiene—mouthwashes with potassium permanganate (KMnO4) solution.
• Appropriate antibiotics against staphylococci, such as cloxacillin, are administered in the dose of 500 mg, 6th hourly along with metronidazole 400 mg, 8th hourly to treat anaerobic infections.
• It takes about 3–5 days for the inflammation to settle down.

2. Surgical treatment is indicated when there is pus.

• Under general anaesthesia, an adequate vertical incision is made in front of the tragus of the ear up to the deep fascia.
• Open the deep fascia in two or three places and drain with a blunt haemostat so as to avoid damage to the facial nerve.
• This is described as Blair’s method of drainage of parotid abscess. The drainage tube has to be kept which can be removed after 3–4 days.

Drainage Of Parotid Abscess

• Should not wait for fluctuation
• High-grade fever and toxicity are indications
• Vertical incision
• Hilton’s method is preferred to break multiple loculi

Surgical Anatomy Of The Subman-Dibular Salivary Gland

• Submandibular salivary gland is located in the submandibular triangle. It lies partly below and partly above the mandible.
• It is in very close contact with the belly of the digastric muscle. At surgery, once the deep fascia is opened, the intermediate tendon of the digastric is located and when it is retracted downwards, mobilisation of the gland becomes easy.
• The submandibular salivary gland is divided into a superficial and a deep part by the mylohyoid muscle which forms the oral diaphragm. During excision of the gland, a few fibres of mylohyoid are also removed. When the submandibular salivary gland enlarges, it is digitally palpable because the deep portion is deep to the mylohyoid and it is in the floor of the mouth.
• The facial artery enters the gland from its posterolateral surface and deeply grooves the gland. It is ligated at this place first during excision of the gland. After grooving the gland, it ascends laterally and curls around the lower border of the mandible to enter the face. It is also ligated at this place.
• The main duct of the submandibular gland, Wharton’s duct arises from the deep part of the gland and opens on a papilla beside the frenulum of the tongue in the oral cavity.
• In a deeper plane, the gland is related to two nerves—lingual and hypoglossal.

Chronic Submandibular Sialoadenitis

• Obstruction is the most important cause of submandibular sialoadenitis. Another cause is trauma to the floor of the mouth.
• Obstruction can be due to stone disease, (calculus—most common) stricture of the duct, or fibrosis of the papilla.
• The causative organism is Staphylococcus

Sialoadenitis Due To Calculi

The disease starts with acute bacterial sialoadenitis which occurs secondary to obstruction. The submandibular gland has a poor capacity for recovery following infection. Despite control of acute symptoms with antibiotics, the gland becomes chronically inflamed.

Calculi (80% of them occur in the submandibular salivary gland) commonly occur in the duct and also within the gland and produce recurrent sialoadenitis.

Calculi are more common in the submandibular salivary gland than the parotid gland because of the following reasons.

1. Higher mucin content in the submandibular salivary gland secretions.
2. Calcium and phosphate content in the secretion is high. (Hence, 80% of them are radioopaque, detected by plain X-ray)
3. Nondependent drainage of the secretions. The gland is in the neck and the opening of the duct is in the oral cavity.
4. Kinking or hooking of the submandibular duct by the lingual nerve.

Sialoadenitis Due To Calculi Clinical Features

• Salivary colic: It is a severe pricking type of pain which is exaggerated at the. time of meals.
• Salivary secretions are induced by a meal or lemon (lemon juice test). As a result of blockage due to a stone, the tension within the gland increases, resulting in pain.
• Lingual colic: If a calculus is situated within the submandibular duct where it is hooked by the lingual nerve, pain can radiate to the tongue as a result of irritation to the lingual nerve.
• Enlargement of the salivary gland during meals is the characteristic feature of salivary calculus.
• Classically, submandibular salivary gland swelling is located in the submandibular region. It is firm in consistency with a lobular surface. It is tender and both lobes are enlarged.
• It is digitally palpable (the submandibular lymph node is palpable only in the neck) both inside the oral cavity and in the neck. The swelling will reduce in size once the stimuli are withdrawn (after meals)

Submandibular Salivary Gland Enlargement

• Location-Submandibular region
• Lobular, firm swelling
• By digitally palpable
• Stone may be palpable within the duct, intraorally
• The stone may be palpable within the gland (in the neck), within the duct (intraorally), or sometimes it may be seen at the orifice of the submandibular duct on the side of the lingual frenulum.
• It is not uncommon to get severe septic sialoadenitis with gross swelling of the gland and inflammatory oedema almost like Ludwig’s angina.

Treatment

An oblique lateral or posterior oblique occlusal radiography may demonstrate a stone.

1. Stone in the submandibular duct: This can be removed by incising the mucosa over the floor of the mouth, after stabilising the stone. Removal of the stone is followed by a gush of old dirty contents of the submandibular gland.
2. Chronic sialadenitis: This requires excision of the submandibular salivary gland. Three steps of dissection of the gland include incision, mobilisation and excision.

Incision: It should be a skin crease incision over the lower pole of the gland. The posterior limit of the incision should be at least 2 cm away from the angle of the mandible, to avoid damage to the cervical branch of the facial nerve. The incision is deepened till the deep fascia is opened.

• Mobilisation of the gland: Division of the facial artery twice, once in a deeper plane on the posterolateral aspect and another at the superolateral aspect close to the lower border of the mandible is an important step which gives mobilisation of the gland. Separation of the gland from mylohyoid fibres by dividing small arteries completes the mobilisation.
• Excision of the gland: This is done by ligating and dividing the submandibular duct.
• Complications of excision include damage to the lingual nerve, marginal mandibular nerve or even to hypoglossal nerve. Seroma and infection are the other complications.

Salivary Gland Tumours

International Classification

1. Epithelial tumours
2. Non-epithelial tumours

1. Epithelial tumours

Adenoma

1. Pleomorphic adenoma
2. Monomorphic adenomas
   • Adenolymphoma (Warthin’s tumour)
   • Oxyphilic adenoma (Oncocytoma)
   • Other types

2. Mucoepidermoid tumours

3. Acinic cell tumour D. Carcinoma

1. Carcinoma in pleomorphic adenoma
2. Adenoid cystic carcinoma
3. Undifferentiated carcinoma
4. Adenocarcinoma
5. Epidermoid carcinoma
6. Acinic cell tumour
7. Muco epidermoid carcinoma
8. Malignant mixed tumour.

2. Non-epithelial tumours

1. Lipoma
2. Lymphoma
3. Neurofibroma
4. Lymphangioma
5. Sarcoma

Salivary gland tumours are not uncommon. There are dozens of histological types of salivary gland tumours.

• However, pleomorphic adenoma and adenolymphoma are the common benign types. Carcinoma arising in pleomorphic adenoma, mucoepidermoid tumours and adenoid cystic carcinoma are important malignant tumours.
• In incidence, 80% of salivary gland tumours are found in parotid glands, out of which 80% are benign and 80% of benign tumours are pleomorphic adenomas.
• In the submandibular salivary gland, 50% are benign and 50% are malignant.
• Of the minor salivary glands, 90% are malignant. Thus, the incidence of malignancy increases from major to minor salivary glands.

Pleomorphic Adenoma Of Parotid Gland (Mixed Tumour) Pathology

• Epithelial cells proliferate in strands or may be arranged in the form of acini or cords.
• There are also myoepithelial cells which proliferate in sheets. They are called spindle-shaped cells.
• The tumour produces mucoid material, which displaces and separates the cells resembling cartilage in the histological section.

Because of the presence of epithelial cells, myoepithelial cells, mucoid material, pseudo cartilage and lymphoid tissue, the tumour is called pleomorphic adenoma.

• As the tumour grows, it compresses the normal parotid tissue and the branches of the tumour penetrate the thin capsule and enter the substance of the parotid. Simple enucleation will result in a recurrence. Hence, a superficial parotidectomy has to be done.

Parotid Tumours Pathology Clinical features

1. Middle-aged women, around 40 years, are commonly affected.
2. Typically, the history of a very slow-growing swelling for a few years is usually present.
3. The swelling is painless. Any painless swelling near the ear is best assumed to be parotid gland neoplasm unless proved otherwise.

Parotid Tumours Signs

1. 1. Parotid swelling has the following classical features.
   • It presents as a swelling in front, below and behind the ear.
   • Raises ear lobule.
   • The retromandibular groove is obliterated
2. It is rubbery or firm. Soft areas indicate necrosis. In long-standing cases, it can be hard. The surface can be nodular or sometimes bosselated. Skin is stretched and shiny. However, being a benign tumour it is neither adherent to the skin nor to the masseter.

Clinical Examination Of Parotid Tumours

• Swelling proper
• Facial nerve involvement (80–90% cases of malignancy)
• Fixity to mandible and masseter
• Deep cervical nodes
• Opening of parotid duct
• Shift of tonsil and pillar of the fauces
• Other salivary glands (both sides)

3. After a few years, pleomorphic adenoma shows features of transformation into malignancy (carcinoma ex pleomorphic adenoma).

It should be suspected when

• It starts growing rapidly
• Skin infiltration occurs
• Facial nerve paralysis
• Gets fixed to the masseter muscle
• Red, dilated veins over the surface
• The presence of lymph nodes in the neck
• The tumour feels stony hard.

Intraoral Examination

• Approximately 10% of the parotid tumours are behind the facial nerve in the deep lobe.
• This is appreciated by intraoral examination wherein the tumour presents with a
  parapharyngeal mass which displaces the tonsil or soft palate medially.
• Deep lobe tumours present as dysphagia. Such tumours may not show gross swelling on the outer aspect but as they grow, they pass through the stylomandibular tunnel of Patey and push the pharyngeal wall, tonsil and soft palate. These tumours are called dumbbell tumours.

Intraoral Examination Investigations

Slow-growing parotid tumours should not be subjected to biopsy for 2 reasons.

• Injury to the facial nerve
• Seeding of tumour cells in the subcutaneous plane causes recurrence in about 40–50% of cases.

1. Fine needle aspiration cytology (FNAC) is done to confirm the diagnosis and rule out malignancy.
2. CT scan is done when the tumour is arising from the deep lobe. It helps to define the extra glandular spread, the extent of para pharyngeal disease, and cervical lymph nodes.
3. FNAC of the lymph nodes which are palpable in the neck in cases of malignancy of the parotid gland.
4. X-ray of the bones (mandible and mastoid process) to see for bony resorption.
5. MRI is a better investigation but expensive—CT scans and MRIs lack specificity for differentiating benign and malignant lesions.

Intraoral Examination Treatment

Conservative superficial parotidectomy.

It is the standard surgery done for benign pleomorphic adenoma. It means the removal of the entire lobe containing the tumour which is superficial to the facial nerve.

The facial nerve should always be preserved. Enucleation should never be done as it causes recurrence. It is difficult to remove a recurrent tumour.

A few important steps of superficial parotidectomy

1. Adequate exposure by an incision which starts in front of the tragus of the pinna vertically descends downwards, curves around the ear lobule up to the mastoid process and is carried downwards in the neck (‘Lazy S’ incision).
2. Recognising the facial nerve at surgery
   • The facial nerve lies 1 cm inferomedial to the pointed end of the tragal cartilage of the external ear.
3. Developing a plane: The facial nerve and retromandibular vein divide the parotid gland into superficial and deep lobes. Benign tumours do not invade this faciovenous plane of Patey.
4. Gentle handling, good suction and perfect haemostasis help in the clear recognition of the nerve.
5. The tumour along with the lobe should be removed in toto to avoid spillage (which is one of the causes of recurrence).
6. Good suction drainage of the wound is necessary to avoid haematoma, wound infection, etc.

Conservative Superficial Parotidectomy

• Indicated in pleomorphic adenoma
• The tumour along with the normal lobe is removed
• Preserve the facial nerve, even in malignant tumours unless grossly involved
• Avoid rupture of the gland
• Enucleation should not be done as it causes recurrence

Trace the posterior belly of the digastric up to the mastoid process. The facial nerve is in between the muscle and the tympanic plate.

To use a nerve stimulator.

Treatment Of Malignant Pleomorphic Adenoma

• Radical parotidectomy refers to the removal of both lobes, facial nerve, parotid duct, fibres of the masseter, buccinator, pterygoids and radical block dissection of the neck. If the facial nerve is not involved it should be preserved to avoid morbidity. Advanced tumours with fixed nodes in the neck may require radiotherapy even though the response rate is poor.
• Indications for postoperative radiotherapy
• If the deep lobe is involved
• If the lymph nodes are involved
• High-grade tumours
• If margins are positive.

Adenolymphoma (Warthin’s Tumour, Papillary Cystadenoma Lymphomatosum)

• Adenolymphoma is not a lymphoma. It is a misnomer (vide infra).
• It is a benign parotid tumour and next common in pleomorphic adenomas. It constitutes about 10% of parotid tumours.

• Origin of adenolymphoma: During development, some parotid tissue gets included within lymph nodes (preparotid) which are present within the parotid sheath.

Adenolymphoma (Warthin’s Tumour, Papillary Cystadenoma Lymphomatosum) Histology

• It is composed of double-layered eosinophilic epithelium, inner cells are columnar.
• The presence of lymphatic tissue in the stroma, and lymph follicles (hence the name) is characteristic of adenolymphoma.

Adenolymphoma (Warthin’s Tumour, Papillary Cystadenoma Lymphomatosum) Clinical features

1. Middle-aged or elderly males are commonly affected—usually, they are smokers.
2. Can be bilateral, in some cases (10%).
3. It has a smooth surface, and round border with a soft, cystic consistency.
4. Classically, situated at the lower pole of the parotid elevating the ear lobule.
5. Maybe multicentric
6. This tumour affects only the parotid gland. (Very, very rarely, other glands may be affected.)

Treatment

It has a well-defined capsule. Hence, enucleation can be done.

Mucoepidermoid Tumour

• As the name itself suggests, it consists of sheets of epidermoid cells and cystic spaces lined by mucus-secreting cells.

• In childhood, it is the most common parotid tumour
• They are benign and slow-growing but hard in consistency. (Adenolymphoma and mixed tumours are firm, but mucoepidermoid tumour is hard.) Parotid is the most common site. In cases of minor salivary glands, the palate is the commonest site.
• Mucoepidermoid tumours can infiltrate local tissues, lymph nodes or skin. Hence, a few consider that mucoepidermoid tumours are always carcinomatous.
• Well-differentiated tumours behave like benign tumours. Intermediate ones are aggressive and undifferentiated tumours metastasize early. Mucoepidermoid carcinoma is the most common malignant epithelial neoplasm of the salivary gland.
• The low-grade tumours are composed of predominantly mucous-secreting cells. High-grade tumours have predominantly epidermoid cells.
• Benign tumours need excision and malignant tumours need radical parotidectomy.

Acinic Cell Tumour

• These are the uncommon parotid tumours. Commonly occurs in women.
• The cells resemble those of serous acini and this tumour also has properties of invasion like mucoepidermoid tumour. It tends to be soft and sometimes cystic.

Oxyphil Adenoma

Also called oncocytoma. It occurs exclusively in the parotid gland. It is a solid tumour, that occurs in the sixth decade of life.

Adenoid Cystic Carcinoma

• It is a highly malignant tumour consisting of cords of dark staining cells with cystic spaces containing mucin. It also consists of myoepithelial cells and duct epithelium.
• Even though slow growing, it spreads along the perineural tissue and may invade the periosteum or medullary bone at a distance. This bone resorption results in bony tenderness.
• These tumours have a high incidence of distant metastasis but in general, they display indolent growth. Skip lesions are common as they spread along the nerve tissue, which leads to treatment failure.
• Local infiltration, lymphatic and blood spread and local recurrence are important features.
• It is hard and fixed and can produce anaesthesia of the skin overlying the tumour.
• Early cases are treated by radical parotidectomy with block dissection of the neck. However, many cases present late at the hospital. Thus, palliative radiotherapy is given to reduce pain and to arrest the progress of the disease.

Complications Of Parotidectomy

• Flap necrosis—Avoid acute bending of the incision and use gentle retraction
• Facial nerve palsy—Careful identification
• Fluid collection—Blood or seroma—perfect haemostasis and drain should be used
• Salivary Fistula—The Duct should be ligated
• Frey’s syndrome—Occurs in 10% of cases Observe 5‘F’s

Interesting Most Common for Salivary Glands Summary of Malignant Salivary Gland Tumours

• To find out the exact type of malignant tumour is of interest to pathologists. Clinically, one can suspect malignancy when a salivary tumour has any of the following features:

Malignant Parotid Tumors

Most Common For Salivary Glands

• The most common benign parotid tumour in adults—is pleomorphic adenoma
• The most common benign parotid tumour in children—haemangioma
• The most common malignant tumour in the submandibular gland—is adenoid cystic carcinoma
• The most common minor salivary gland tumour is adenocarcinoma
• The most common site of squamous cell carcinoma is the submandibular salivary gland
• The most common response to radiotherapy among malignant tumours is adenoid cystic carcinoma

1. Rapidly growing neoplasm
2. Change in consistency (the tumour tends to be hard)
3. Fixity to underlying muscle such as masseter as in parotid tumours
4. Fixity to mandible as in parotid or submandibular tumour
5. Involvement of facial nerve as in 80% of cases of malignant parotid tumours
6. Resorption of adjacent bone such as mastoid, tenderness as in adenoid cystic carcinoma.
7. Significant hard nodes in the neck.

• They are treated by radical sialadenectomy with radical block dissection of the neck. Radiotherapy is used as a palliative treatment.

Miscellaneous Frey’s Syndrome—Gustatory Sweating

• It occurs after surgery for parotid tumours, surgery in the region of the temporomandibular joint, or due to injury to the parotid gland. Injury to the auriculotemporal nerve can occur at a site where it turns around the neck of the mandible. The injury is manifested at a later date (2–3 months).
• Because of the injury, post-ganglionic parasympathetic fibres from the otic ganglion are united with sympathetic fibres of the superior cervical ganglion which supplies the vessels and sweat glands over the skin overlying the parotid region.

Parts Supplied By Auriculotemporal Nerve

1. Auricular part:
   • External acoustic meatus
   • Tympanic membrane surface
   • Skin of auricle above external acoustic meatus
2. Temporal part:
   • Hairy skin of the temple

• As a result of this, whenever the act of chewing or mastication is started, there is increased sweating and hyperaesthesia in the region supplied by the auriculotemporal nerve (cutaneous branch of the mandibular division of the trigeminal nerve). Hence, it is called auriculotemporal syndrome.
• Diagnosis starch iodine test: Paint the affected area with iodine which is allowed to dry, before applying the dry starch.
• The starch turns blue on exposure to iodine in the presence of sweat.

Parts Supplied By Auriculotemporal Nerve Prevention

The principle is to provide a barrier between the skin and the parotid bed by using a temporalis facial flap or sternomastoid muscle flap.

Parts Supplied By Auriculotemporal Nerve Treatment

1. Reassurance
2. Aluminium chloride—antiperspirant which is a useful astringent
3. Denervation by tympanic neurectomy
4. The latest treatment includes the injection of botulinum toxin into the affected skin.

Rare Cause Of Salivary Gland Enlargement Sjogren’s Syndrome

The diffuse infiltration of salivary and lacrimal glands with lymphocytes results in the enlargement of glands and the slow destruction of acini. Thus, clinical features include dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia). These along with a third component rheumatoid arthritis, forms the triad of Sjogren’s syndrome (primary).

• 30% of patients with systemic lupus erythematosus and all patients with primary biliary cirrhosis develop Sjögren’s syndrome. This is termed secondary Sjpgren’s syndrome.
• Other features include—the disease is 10 times more common in females and presents with painful enlargement of the glands.

Complications

1. Lymphomatous transformation (high in primary)
2. Oral candidiasis.

Mikulicz’s Disease

Due to autoimmune mechanism1, symmetrical enlargement of all salivary glands and lacrimal gland enlargement occurs. Dry mouth and narrow palpebral fissures are diagnostic of this
condition.

Drugs

Carbimazole and thiouracil can cause enlargement of salivary glands.

1 Can be associated with autoimmune pancreatitis— Steroids may help in the treatment of both conditions.

Metabolic Disorders

Diabetes and acromegaly are the other causes.

Parotid Fistula

• It is an uncommon condition which commonly occurs after surgery on the parotid gland
• Any surgery on the parotid gland – Superficial parotidectomy, drainage of abscess, surgery for carcinoma cheek, and faciomaxillary trauma are the causes.
• Discharging watery fluid, exaggerated by keeping lime in the mouth
• A fistulogram confirms the diagnosis Exploration and excision of the fistula and ligation of the duct are required

Facial Nerve Palsy

Indications for Different Types of Surgery

1. Early immediate nerve repair, in case of injury to the nerve.
2. Late nerve crossing by suturing peripheral branches of the facial nerve to one of the following nerves:
   • Hypoglossal nerve, spinal accessory nerve
   • Phrenic nerve
3. Surgery to achieve movement in long-standing facial palsy (usually after 1 year)

Static procedures

• Suspension of lips, cheek and angle of mouth to zygomatic bone or temporal fascia using fascia lata, palmaris longus tendon or other alloplastic materials.
• Medial canthoplasty to reduce epiphora
• Lateral tarsorrhaphy (canthoplasty) to prevent exposure to keratitis due to widened palpebral fissure.

Dynamic procedures

• Muscle transfer with carefully preserved muscle nerve and vessel, e.g. temporalis muscle transfer, masseter muscle transfer.
• Cross-face nerve transplantation using the sural nerve using a microscope, the sural nerve is sutured to the two or three relatively insignificant branches of the facial nerve (selected by intraoperative electric stimulation) on the normal side.
• The other end of the sural nerve is sutured to the distal end of the divided facial nerve on the paralysed side.
• Free neurovascular gracilis muscle graft using microvascular techniques.

Nerve Injuries

They are classified as follows (Seddon classification)

Neuropraxia

There is physiological paralysis of conduction in the intact nerve fibres as a result of stretching or distortion without any organic rupture. Thus nerve fibres are intact within the intact sheath, without anatomical disruption. Hence, Wallerian degeneration does not occur.

It produces sensory loss, paraesthesias and weakness of muscles for a few days. Recovery takes place within a few days to a few weeks (6 weeks) without residual neurological damage.

Causes Of Neuropraxia

• Bone fragments
• Tourniquet
• Plaster cast
• Postoperative

Causes Of Neuropraxia Treatment

Splinting the limb in a position of relaxation of paralysed muscle groups.

Axonotmesis

Consists of the rupture of nerve fibres (anatomical disruption of the axon) within an intact sheath. It is always associated with neurological deficit which includes anaesthesia, paraesthesia, weakness of muscles and paralysis of muscles.

Wallerian degeneration occurs proximally to the next proximal node of Ranvier and distally for the remaining length of the axon.

Recovery depends upon 2 factors

1. Proliferation and down growth of axons into distal tubes.
2. Intraneural fibrosis.

AxonotmesisTreatment

1. Splinting of the limb
2. Care of the skin
3. Maintain nutrition of the limb
4. If the regeneration is delayed or does not take place, then surgical exploration of the nerve followed by excision of scar tissue, callus, or neuroma has to be done.

To know the progress of regeneration, the following clinical criteria are followed:

1. Tinel’s sign: The course of the nerve is lightly percussed with a hammer from below upwards. A tingling sensation is experienced when the level of regeneration is reached.
2. Recovery of muscles from time to time.

Causes Of Axonotmesis

• Bone fragments
• Tourniquet
• Plaster cast
• Postoperative

Neurotmesis

It is produced by penetrating wounds and cutting wounds resulting in partial or complete division of nerve sheath and nerve fibres. Accidental division of nerve can take place during surgery also.

Partial lesions produce a lateral neuroma of the nerve. The complete division produces a terminal neuroma at the end of the nerve.

Nerves In Danger At Surgery

• Facial nerve—Parotidectomy, mastoid surgery
• Lateral popliteal nerve—Short saphenous varicosity
• Lower limb nerves—Sarcoma of limb
• Recurrent laryngeal nerve—Thyroidectomy.

Nerves In Danger At Surgery Treatment

Suturing of the nerve provided

1. No infection.
2. No contamination of a wound with a foreign body.
3. No tension between the two cut ends of the nerve.
4. Even with surgical repair, recovery is never complete.

Principles of nerve repair

The accurate coaptation of the nerve ends without tension in a healthy bed of tissue is the main principle of nerve grafting.

Procedure

Once cut ends of the nerve are defined, ragged edges if any are trimmed. If necessary mobilisation of the nerve can be done.

Sutures are placed in the epineural tissue using fine sutures, e.g. 8–0 for the median nerve, 6–0 for the large nerve (sciatic nerve), and 2–0 for digital nerves.

There should not be any tension on the suture line. If a significant ‘gap’ is present between the two cut ends, it is better to perform nerve grafting than a difficult primary repair.

Clinical Examination Of The Salivary Glands

It should be remembered that if 1 salivary gland is enlarged, examine all 3 salivary glands and also on both sides because some diseases can affect all glands on both sides.

History

Swelling: Most often parotid or submandibular gland lesions present as swelling. In such a case, you have to ask the duration of the swelling and growth pattern. Slow growing neoplasm of the parotid gland is a pleomorphic adenoma.

Generally, the patient says it has been there for 5–10 years and it is slow growing. If such a tumour grows rapidly it is due to malignant transformation of the tumour.

It means pleomorphic adenoma is turning into carcinoma. In such cases it also causes pain.

• In cases of submandibular swellings, swelling may appear or may increase in size following a meal. It is also associated with pain which is characteristic of calculous in the duct.

Pain: Pain can be due to the following conditions. In acute parotitis, the gland is enlarged and the patient has significant pain. Usually, it is bilateral. A parotid abscess can give rise to throbbing pain. Mild pain can also be due to malignant transformation in a pleomorphic adenoma.

Discharge: Watery flow from a sinus in the region of the parotid gland is a parotid fistula. It occurs when the parotid duct is damaged or injured. In such cases elicit a history of surgery in the parotid region—may be for a swelling (Lymph node) or following drainage of parotid abscess.

Inspection And Palpation

1. Swelling: If you see a swelling describe it in the usual way. Parotid swellings are usually situated below, in front of and behind the lobule of the ear.

Often ear lobule is raised Ear lobule may not be raised in a few cases because the tumour may arise from the lower pole of the parotid. Typically pleomorphic adenoma will have a nodular surface.

Adenolymphoma will have a smooth surface and carcinoma will have an irregular surface. As the upper attachment of the parotid fascia is to the zygomatic arch, the upper extent of the swelling is limited maximum only upto the zygomatic process.

Note down the retromandibular groove (between the mandible and mastoid process) which is usually obliterated in parotid swellings.

Check List—Examine

• All salivary glands.
• Facial nerve
• Hypoglossal nerve
• Lymph nodes in the neck
• Intraoral examination
• Mandible
• Liver and spleen (Autoimmune diseases)
• Masseter contraction test: Ask the patient to clench the teeth and check the mobility of the gland. Restricted mobility suggests malignant transformation of the tumour.
• Bidigital palpation of the submandibular duct and gland: It can be done by inserting the finger between the alveolus and tongue. The other finger is placed under the jaw.

Slowly both fingers are withdrawn. If there is a calculi in the duct it can be appreciated.

The finger inside the oral cavity can also feel the deep part of the submandibular salivary gland if it is enlarged but not when the submandibular lymph node is enlarged because the deep lobe is situated above the mylohyoid muscle and lymph node below the muscle.

2. Intraoral examination: With good illumination, the following points are to be noted.

• Examination of the parotid duct — Stensen’s duct: opposite the upper 2nd molar tooth. If pus is seen coming out, it is a case of suppurative parotitis especially when you apply gentle pressure over the surface.
• Examination of the orifice of the Wharton’s duct (submandibular duct)
• Examination of the tonsils and pharyngeal wall: In deep lobe enlargement of the parotid gland, the tonsils and pharyngeal wall may be pushed medially. The tongue should be depressed with a tongue depressor and with good light this test should be done.
• Calculous disease is more common in the submandibular salivary gland
• Tumours are more common in the parotid gland.