Salivary glands

Fig. 4.1 Submandibular salivary gland swelling.

Investigations

   Plain films: may demonstrate calcified salivary stones.

   Sialography: reveals duct obstruction, sialectasis, filling defects. Pre-contrast, filling, and emptying phase films are taken. Contrast medium is lipiodol (iodine-based).

   USS: can demonstrate tumours, lymph nodes, stones. Deep lobe difficult to visualize.

   MRI: can demonstrate tumours, nodes, stones. Can be combined with ductal contrast to show obstructive disease. High-resolution visualization of facial nerve is debatable.

   CT: as MRI.

   FNA: with 23G (blue) needle gives as much diagnostic information as a 21G (green).

    •   arguments against FNA—no change in management as ‘superficial parotidectomy is treatment of choice’, risk of seeding (theoretical);

    •   arguments for FNA—identification of benign vs malignant lump, non-surgical disease (e.g. sarcoidosis/lymphoma), intra-parotid metastatic lymph node disease (e.g. from skin cancer).

   Needle core biopsy with larger needle under USS advocated by some—higher diagnosis rates as architecture preserved (see image Fine needle aspiration for cytology or biopsy, p. 77).

   Scintigraphy:

    •   radio-isotopic study of salivary gland function undertaken by injecting 40MBq technetium pertechnetate intravenously and collecting a series of images from a gamma camera;

    •   during study salivary flow rate is stimulated with lemon juice;

    •   results give an idea of total salivary function;

    •   can reveal Warthin’s tumour (rarely used).

   Sialadenoscopy: technique in which an endoscope is passed down the parotid or submandibular duct with a view to diagnosing causes of duct obstruction. It is possible to therapeutically remove calculi or dilate strictures using minimally invasive techniques.

Xerostomia

Definition

Subjective sensation of dry mouth. Not always associated with disease nor clinically apparent reduction in quantity or quality of saliva. More common in image and elderly patients. Has following effects:

   Difficulty in chewing and swallowing (due to limited increase in salivary flow rate from resting levels).

   Erythematous and atrophic mucosa.

   Lobulation and depapillation of the tongue.

   Dental caries (this is most frequently seen around the cervical margins of teeth).

   Oral candidosis and angular cheilitis.

Primary xerostomia: pathology of salivary glands

   Irradiation glands, including radioactive iodine therapy.

   Sjögren’s syndrome.

   Sarcoid.

   HIV.

   Cystic fibrosis.

Secondary xerostomia: systemic disease

   Drug therapy.

   Disorders leading to fluid/electrolyte imbalance:

    •   dehydration;

    •   diarrhoea and vomiting;

    •   diabetes;

    •   congestive cardiac failure (CCF) and oedema.

   Neurological:

    •   organic brain disease;

    •   drugs (anticholinergics and sympathomimetics);

    •   psychological—mouth breathers.

   Anxiety.

   Drug-induced xerostomia.

Epidemiology

   Most prevalent cause for xerostomia.

   Drugs commonly implicated:

    •   antihistamines;

    •   antidepressants;

    •   anticholinergics;

    •   antihypertensives;

    •   antipsychotics;

    •   anti-Parkinson agents;

    •   diuretics;

    •   sedatives.

Management

Options for management include drug dose reduction or use of alternative medication with reduced anticholinergic activity. Consider modification of dosing schedule to allow maximum salivary flow at night (xerostomia is often worse at night). Avoidance of sublingual preparations of drug.

Sjögren’s syndrome

Definition

Chronic multisystem autoimmune exocrinopathy.

Epidemiology

0.5–2% population affected, ~90% image, mean age at presentation 50 years.

Cause

Unknown—thought to be triggered by an environmental agent in person with genetic predisposition (associated with HLA-B8 and DR3).

Classification

   Primary: affects salivary and lacrimal glands (= Sicca syndrome).

   Secondary: 50–60% of patients have another connective tissue or autoimmune disease, e.g.:

    •   rheumatoid arthritis (15% also have Sjögren’s syndrome (SS));

    •   systemic lupus erythematosus (SLE) (30% have SS);

    •   scleroderma;

    •   polymyositis;

    •   thyroiditis;

    •   primary biliary cirrhosis.

Clinical

   Persistent xerostomia and xerophthalmia >3 months.

   Salivary and lacrimal gland enlargement—if unilateral consider B-cell MALT lymphoma as ↑ incidence in SS (particularly Sicca).

   Parotitis/ascending infections.

   Dry skin, nasal, and vaginal mucosa.

   Signs of associated connective tissue disorder (CTD).

Investigation

   Stimulated and unstimulated saliva flow.

   Sialography: punctuate sialectasis and delayed emptying.

   Labial gland biopsy.

   Bloods: erythrocyte sedimentation rate (ESR), autoantibodies (rheumatoid factor, anti-Ro, anti-La).

   Schirmer test:

    •   blotting paper test for tear production;

    •   <5mm/5min.

Diagnosis

Diagnosis made on the basis of positive findings in four out of the following six categories:

   Ocular symptoms.

   Oral symptoms.

   Ocular signs: positive Schirmer test or positive Rose Bengal score (for corneal ulceration).

   Histopathological features: lower labial gland biopsy showing focal inflammatory cell infiltrate replacing acini.

   Salivary function testing: unstimulated total salivary flow rate <1.5mL in 15min, positive salivary scintography or sialography.

   Serum testing—autoantibodies: presence of at least one of the following antibodies: Ro/SS-A or La/SS-B, antinuclear antibodies, rheumatoid factor.

Management

   Saliva substitutes/stimulation.

   Pilocarpine (muscarinic parasympathomimetic) if some residual functioning salivary tissue:

    •   start very slowly and increase gently to avoid side effects;

    •   side effects include ↑ BP and pulse rate, gastrointestinal symptoms, and sweating.

   Patients should be treated in a multidisciplinary fashion with input from:

    •   rheumatology;

    •   ophthalmology;

    •   OMFS;

    •   general dental practitioner.

   Management of associated disease including low threshold for scanning/biopsy if risk of lymphoma.

Diffuse gland swelling

Swelling is a common symptom. It most frequently affects the parotid gland and can be classified as follows:

   Inflammatory.

   Autoimmune.

   Drug reactions.

   Metabolic.

   Neoplastic.

   Miscellaneous.

    Neoplasia usually produces a focal swelling in the gland. The one notable exception to this is MALToma which often produces diffuse salivary gland swelling and can mimic an inflammatory cause.

Inflammatory

Inflammatory swellings are classified into:

   Acute specific: viral.

   Chronic specific.

   Acute suppurative.

   Chronic suppurative.

Acute specific: viral

   The commonest viral infection to cause parotid swelling is mumps (see image Mumps, p. 455).

   Other viruses implicated in parotid swelling include:

    •   coxsackie virus;

    •   cytomegalovirus;

    •   para-influenze viruses.

HIV

   Associated with generalized lymphadenopathy.

   Parotid enlargement common finding in children with HIV.

   Enlargement is firm, non-tender, and solid.

   Pain is unusual and treatment is not usually required.

   Adult patients with HIV may also present with parotid enlargement. They are prone to developing multiple cysts within the parotid gland.

Chronic specific

Chronic specific inflammatory disorders include:

   Tuberculosis:

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Mar 2, 2015 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Salivary glands
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