Salivary disease: infective disorders and non-neoplastic lesions Flashcards
Structure of salivary glands (4)
Parotid next to ear
Submandibular
Sublingual
Minor glands throughout the mouth
Describe the parotid gland (4)
Largest
Preauricular
Serous secretion - not as thick
Contributes 20-40% of saliva
Describe the submandibular gland (3)
Smaller in size
Mixed (mucous and serous) secretion - mainly mucous
Contributes to 60-70% of saliva
Describe the sublingual gland (5)
Smallest
Located at the floor of mouth (under tongue) between submandibular gland and tongue
Mucous
Contributes up to 10% of saliva
Describe the minor salivary glands (4)
Found mainly throughout mouth -lips, palate, cheeks, tongue Approx 800+ in total Mucous secretion (EXCEPT von Ebner gland at posterior lateral of tongue is serous) Contributes 5-10% of saliva
Non-neoplastic lesions of salivary glands (not tumours)
subcategories (3)
Developmental anomalies
Inflammatory: sialodenitis (inflammation of salivary glands)
Obstruction and trauma
Non-neoplastic lesions of salivary glands: Developmental anomalies (3)
All very rare
May see aplasia (absence of glands)
• Usually associated with other anomalies or syndromes
Heterotopic salivary tissue: (glands normal but in abnormal place
• Stafne’s bone cavity
• Present under the ID nerve close to the angle of the mandible
• Salivary gland tissue in the wrong location, causes a dent in the mandible
• e.g. Salivary gland tissue in the angle of mandible
Causes of sialodenitis (2)
Acute (always related to the infection):
• bacterial or viral
Chronic:
• bacterial, post-irradiation, Sjogren’s
Bacterial sialodenitis (2)
Acute parotitis: o Ascending infection, ascending upwards into the salivary gland o Oral bacterial (S.aureus) bacteria going into the gland o Acute swelling and pain o Pus exudates from ducts Usually secondary to dry mouth: o Radiotherapy o Sjogren's syndrome o Drug induced - anti-depressants
Two forms of recurrent parotitis (3)
o In adults - recurrent infection secondary to dry mouth
o In children - recurrent Parotitis of childhood (recurrent infection of the parotid gland)
o Both forms are associated with ascending infection, often Staph Aureus
Recurrent parotitis in adults - epidemiology and causes (6)
40-60 f>M Often unilateral Secondary to xerostomia (mirror sticking to the mouth) Due to recurrent ascending infections Often secondary to: • Sjogren's syndrome • Drug-induced dry mouth • Radiation damage
Recurrent parotitis in children - epidemiology and causes (5)
o 4 months - 15 years o M=F o May resolve at puberty o Bilateral o No obvious cause or predisposing factors
Recurrent parotitis in children - signs and symptoms (6)
o Bilateral parotid swellings o Sudden onset o Days - weeks duration o Periods of quiescence o Not suppurative - no pus will come out o May be evidence of infection: • Pain • Redness • Fever
Recurrent parotitis in children - imaging (4)
o Sialography shows punctate sialectasis
o Iodine into salivary duct, if a normal gland would see branching architecture, when there’s damage to the ducts, the iodine leaks out, get a ‘snowstorm’ appearance
o Gradual destruction of acinar elements
o Reduced flow
Recurrent parotitis in children - histology (4)
o Salivary ducts dilated
o Acini produces the saliva that goes into the ducts and then into the mouth
o If there is infection, the acini are the first to get irreversibly damaged
o Inflammatory cells (lymphocytes) present
Viral sialodenitis (mumps) epidemiology (5)
o Epidemic parotitis o Mumps virus (paramyoxovirus) o Now quite rare since MMR vaccine introduced o <1000 cases per year o 2006-08 epidemic
Viral sialodenitis (mumps) incubation period and signs/ symptoms (6)
o Incubation period 2-3 weeks • Direct or droplet spread o Acute bilateral parotid swelling o Usually in children o Very painful, malaise and fever o Self-limiting 10-14 days o May spread to other glands/organs
Complications of mumps (6)
o Orchitis (up to 30%) o Meningitis (10%) o Oophoritis (5%) o Pancreatitis (5%) o Cranial nerve palsies o VIII nerve deafness
Chronic sialodenitis - causes (2)
- Stone forming in gland or secretion really thick - blockage present
- Usually secondary to duct obstruction due to calculi
Salivary calculi - what are they and who do they affect (6)
o An accumulation of calcium and phosphate salts which deposit in the salivary ducts or gland the saliva slows down, produce less/thicker saliva, as a result becomes static and starts to solidify o Usually unilateral o Male : Female 2:1 o Submandibular approx 80% o Parotid 20% o Minor glands 1-15%
Submandibular gland calculi (2)
- Distribution is equal in posterior duct, gland and floor of mouth
- Lower occlusal, standard occlusal x-rays if you think it is in the floor of the mouth
What is a salivary calculus (2)
• Concentric accumulation of calcium salts around cellular debris and mucous - formed in increments
Sequestrae of a salivary calculus (4)
Obstruction by calculus: narrowing of duct, trauma or changes in saliva flow
–>
Saliva retention and inflammation: inflammation destroys the acini, replaced by fibrous tissue that squeezes duct more
–>
Swelling and fibrosis
–>
Fibrosis and loss of function
Submandibular salivary calculi histology (5)
o Dark purple - serous acini o Light purple - mucous o There are a lot more acini than ducts o Gland with stone o Right: Sialinitis, cant see any acini because they have been destroyed but cans see some ducts, seeing lymphocytes which have destroyed the acini
Why are there more submandibular gland stones than parotid? (3)
o More mucous so thicker saliva
o Duct not straight - more likely to have obstruction
o Pushing against gravity
Radiation sialodenitis (7)
- Occurs at doses over about 20Gy
- High risk of permanent damage over 30Gy
- Severe damage at doses of over 50Gy
- Serous acini are most sensitive
- Inflammation and fibrosis of glands - no acini, don’t get saliva production
- Loss of function
- Important consideration in cancer patients
Radiation sialodenitis - histology (2)
no acini, there are ducts and inflammatory cells
Non-neoplastic lesions of salivary glands: obstruction and trauma (3)
o Salivary calculi
o Mucous Cysts - mucoceles
o Necrotising sialometaplasia
Types of mucoceles (2)
- Mucous extravasation cyst
* Mucous retention cyst
Features of mucoceles (5)
o Lower lip commonest site - easy to traumatise o Most common in children o Usually extravasation cysts o Painless swellings o Rupture and recur
Mucous extravasation cyst (7)
o 85% of mucoceles
o Younger age groups
o Peak: 20-30 years
o Lower lip commonest site 50%+
o Break in salivary gland,
o instead of being pushed out, it pools in the connective tissue
o Wall of granulation tissue (because of inflammation)- not true cyst as doesn’t have an epithelial lining but does have a wall of epithelial lining
Mucous extravasation cyst histology (4)
Cyst lies in mucosa
-surface epithelial CT
Lumen filled with mucous
Chronic inflammatory cells in lumen - macrophages filled with mucous
Lining of inflamed, compressed granulation tissue
Mucous retention cyst (6)
- 15% of mucoceles
- Due to blocked duct on the surface: saliva can’t get out, leads to back pressure, duct swells and enlarges (dilation and cyst formation)
- Older age groups
- Often over 40 years
- Peak: 50-60 years
- Floor of mouth, buccal mucosa
Mucous retention cyst histology (4)
Cyst lumen filled with mucous
Ductal EPITHELIAL LINING which holds it together
Cyst wall of fibours tissue with glands
Less inflammation becuase mucous not in direct contact with CT (epithelial lining in between)
Where else may mucoceles recur except for lower lip? (4)
• May also arise on palate, tongue, cheeks and lip
Ranula (7)
- Arise in the floor of mouth
- Usually extravasation cysts
- Arise from sublingual gland (obstruction in this gland)
- Usually in children
- Painless swellings
- Rupture and recur
- Usually 2-3 cm
Necrotising sialometaplasia (7)
- Important because can be mistaken for malignancy
- Presents as indurated, ulcerated swelling
- Usually on the palate
- Often biopsied as ‘malignant’
- Heals spontaneously in 4-8 weeks
- Benign inflammatory disease
- Raised rolled edges, if leave will go itself
Necrotising sialometaplasia histology (5)
Histology may look like carcinoma
Squamous metaplasia of salivary ducts: islands of squamous epithelium deep in CTs
But also see necrosis of acini with ‘ghosts’ of normal structures
• Normally not so squamous
• Acini been destroyed so just see the outline of cells
