Non-Neoplastic Salivary Gland Disease Flashcards
1
Q
What is a salivary calculi and where does it form most of the time
A
- Stone can form in a salivary gland or duct
- 80% in submandibular
- 8% in parotid
- 2% in sublingual and minor glands
2
Q
What are the clinical features of salivary calculi
A
- Adult males mainly affected
- Calculi usually unilateral and multiple
- Intermittent obstruction ‘meal time syndrome’, pain and swelling of gland
- Persistent obstruction leads to infection, pain and chronic swelling of the gland
- Occasionally asymptomatic until the stone passes forward and can be palpated or seen in radiograph
- Do not cause dry mouth but factors that increase the saturation of saliva (dry mouth, dehydration, obstruction) all predispose to stones leading to viscous cycle
- Parotid saliva is less saturated and so produces fewer stones
3
Q
What is the Pathology of salivary calculi
A
- Saliva is supersaturated, and calcium and magnesium phosphates deposit around a nidus, probably cell debris
- Degenerate cells within the gland can also mineralise and may enter the duct system to act as a nidus
- Mineralisation proceeds incrementally producing a layered structure
- An adherent layer of microbial flora often grows on stones and this, their rough surface and obstruction trigger inflammation and fibrosis around the duct
4
Q
What is the management of salivary calculi
A
- Identify stones by radiography or ultrasound
- Assess degree of damage to the gland from ascending infection and sialadenitis using sialography
- Small stones may sometimes be manipulated out of the duct orifice
- Larger stones or distally places stones:
1. Lithotripsy: ultrasonic shock wave
2. Stones in duct outside of gland can be removed using a basket of fine wire under radiological control
3. Microendoscopy can be combined with laser disruption
4. Duct has to be opened under LA (suture placed behind stone to stop it slipping back) and the incision should be left open to prevent scarring and fibrous stricture forming
5. When stones are within the gland or gland is damaged by recurrent infection - gland will need to excised
5
Q
What are salivary duct strictures caused by and what is the treatment with/without obstruction
A
- Strictures of the duct itself are almost always caused by fibrous resulting from inflammation around a calculus or scarring following surgery
- Usually cause of stricture at parotid papilla is chronic trauma (from causes such as projecting denture clasp) leading to fibrosis
- Obstruction from strictures presents with meal time syndrome
- Once any causative calculus has been removed, no further tx may be required, but persistent obstruction may require dilation of the duct with bougies, excision of the narrow segment of the whole gland
6
Q
What is a mucocele and what are the two types? Where are mucoceles usually found
A
- A mucocele is a cavity filled with mucus
- Salivary mucoceles can be of two types, but these cannot be distinguished clinically, and the difference is of little practical importance
- Mucous extravasation cyst and mucous retention cyst
- Most frequently on lower lip
- Almost never in upper lip - consider alternative diagnosis of salivary gland neoplasm
7
Q
What are the clinical features of mucous extravasation cyst
A
- Termed extravasation cyst even though there is no epithelial lining
- Superficial and rarely larger than 1cm
- In the early stages, appear as rounded fleshy swellings
- Later, they are obviously cystic, hemispherical, fluctuant and blueish due to thin wall
8
Q
What is the pathology of Mucous extravasation cysts
A
- Usually caused by damage to duct => duct rupture => saliva can escape into surrounding tissues => mild inflammation => saliva pools => pools of saliva gradually coalesce to form a rounded collection of fluid (‘mucocele’) with CT wall
9
Q
What is the pathology of mucous retention cysts
A
- Less common
- Epithelial lining because they are salivary ducts that become very dilated following obstruction
- Retention cysts arise both within major glands, usually the parotid, and minor glands
- There is less inflammation because the saliva does not escape into tissues and the pool of mucus is surrounded by duct epithelium
- The epithelium often shows hyperplasia or oncocytic metaplasia
10
Q
What is a ranula and how is it caused?
A
- Distinctive type of mucous extravasation cyst arising in the FOM from sublingual gland
- Structure is the same as other extravasation cysts
- Cause is damage to, or obstruction of, one of the several ducts of Rivinius that drain into the submandibular gland or FOM
11
Q
What are the clinical features of a ranula
A
- Ranulae are usually unilateral and 2-3cm (occasionally extend across whole FOM)
- They are soft, fluctuant and bluish, typically painless but may interfere with speech and mastication
- Sublingual glands secrete continuously, unlike larger glands, and ranulae can therefore reach larger sizes in the loose tissue
- A plunging ranula arises when the mucus passes through the mylohyoid muscle, which is a discontinuous sheet in many individuals, or around its posterior margin. Large volumes of mucus can then collect in the submandibular space and extend down into the neck, sometimes with minimal intraoral swelling
12
Q
How are mucoceles treated
A
- Untreated mucoceles rupture, often repeatedly, and eventually heal spontaneously
- Otherwise they should be excised with the underlying gland - if not, recurrence likely
- Ranulae do not require excision. If the cavity is trained and decompressed by marsupialisation, it will heal spontaneously provided the causative gland (sublingual gland) is removed. Sublingual gland comprises as 20 small glands each with their own duct and only the involved segment needs to be removed if it can be identified
13
Q
What are the main causes of acute sialadenitis
A
- Mumps (paramyxovirus)
- Bacterial parotitis
14
Q
What are the clinical features of acute sialadentitis caused by mumps
A
- Due to paramyxovirus and causes painful swelling of the parotids and other exocrine glands
- Highly infectious - spread by saliva
- Classically children were affected: headache, malaise, fever, painful and tender swelling of the parodies follow an incubation period of about 21 days
- Cases of adolescents: unlike children, may have severe prolonged malaise, and are prone to complications including orchitis, oophoritis, pancreatitis, arthritis, mastitis, nephritis, pericarditis or meningitis
- Immunised adults have reduced disease severity (MMR vaccination)
15
Q
What is the aetiology the clinical features of bacterial parotitis
A
- Suppurative parotitis more commonly seen in pts with severe xerostomia, particularly Sjögren’s syndrome or as an uncommon complication of tricyclic antidepressant tx
- Important bacterial causes: staphylococcus aureus, streptococci and oral anaerobes
- Pain in one or both parotids with swelling, redness and tenderness, malaise and fever
- Regional lymph noes are enlarged and tender and pus exudes or can be expressed from the parotid duct
- Progress of infection depends largely on pts underlying physical state
- Aggressive antibiotic tx required
