20. Neoplastic salivary gland disease Flashcards
What are the 5 malignant salivary gland tumours?
Mucoepidermoid carcinoma
Acinic cell carcinoma
Adenoid cystic carcinoma
Carcinoma ex pleomorphic adenoma
Polymorphous low grade adenocarcinoma
Where does mucoepidermoid carcinoma affect most?
Commonest SG tumour
Parotid and palate
What are the features of mucoepidermoid carcinoma?
Poorly circumscribed
Invasive
Cystic formation cell
3 cell types
What is the first cell type of mucoepidermoid carcinoma?
Squamous/epidermoid cells- intercellular bridges, keratinisation very rare, solid or cystic
What is the second cell type in mucoepidermoid carcinoma?
Mucous producing cells- PAS staining, solid or cystic, cuboidal or columnar goblet like, cyst might break down inducing a granulomatous reaction
What is the third cell in mucoepidermoid carcinoma?
Small, dark stained nuclei
What is low grade mucoepidermoid carcinoma?
Survival 5 years- 90%
More than 50% mucous cells
Cystic spaces
More circumscribed
What is high grade mucoepidermoid carcinoma?
5 year survival is 70%
More squamous and intermediate cells, necrosis and haemorrhage
Where does acinic cell carcinoma affect most?
Low grade tumour
80% affects parotid
What type of cells do acinic cell carcinoma contain?
Shows some cytological differentiation towards acinar cells, but a wide range of histological patterns.
Solid, microcystic, papillary-cystic, follicular
What is the histology of acinic cell carcinoma?
Sheets groups of large polygonal acinar cells
Granular cytoplasms- PAS positive
Vacuolated cells
Intercalated duct like cells
Lymphoid infiltrate in the stroma
What is the survival rate of acinar cell carcinoma?
Well differentiated- 80 to 100%
Poorly differentiated- 65%
Where does adenoid cystic carcinoma affect most?
Middle age/elderly patients
More common in minor salivary glands
What are the symptoms of adenoid cystic carcinoma?
Slow enlarging
Pain
Ulceration
Facial palsy in parotid
What are the 3 histological patterns of adenoid cystic carcinoma?
Cribriform- swiss cheese, basement membrane like material
Tubular- surrounded by desmoplastic stroma
Solid
What are the cell types in adenoid cystic carcinoma?
Duct lining cells- small, basophilic forming pseudo/cysts
Myoepithelial cells
Where can adenoid cystic carcinoma invade into?
Perineural and perivascular invasion without stromal reaction
In bone it spreads via marrow spaces
Recurrence is common
What is the survival rate of adenoid cystic carcinoma?
Survival 5 years- 75%
10-40%
20-20%
Which type of adenoid cystic carcinoma has the most perineural invasion?
Solid tumour type
Has large nests of cells with high nuclear to cytoplasm ratio
What can be used to stain in adenoid cystic carcinoma?
Alcian blue- highlights the pseudocystic glycosaminoglycan material
Where is carcinoma ex pleomorphic adenoma mostly found?
Arises from pleomorphic adenoma from mostly parotid which have been present a long time
They turn into adenocarcinoma or undifferentiated carcinoma
When is carcinoma ex pleomorphic adenoma mostly found?
Peak of incidence is 10 years later than peak for pleomorphic adenoma
Where can carcinoma ex-pleomorphic adenoma metastastise to?
Lymph nodes
Lungs
Bone
What is the prognosis of carcinoma ex pleomorphic adenoma like?
If still inside the capsule of pleomorphic adenoma then it is good prognosis, otherwise poor
Where is polymorphous low grade adenocarcinoma mostly found?
Almost exclusively in minor SG in palate
What are the growth patterns of polymorphous low grade adenocarcinoma?
Trabecular
Cribriform
Papillary
Lobular
What is the histology of polymorphous low grade adenocarcinoma?
Concentric neurotropism
Mucinosis in the stroma
Encasement of benign residual salivary glands
What is the differential diagnosis for polymorphous low grade carcinoma?
Adenoid cystic carcinoma- hyperchromatic nuclei, more infiltrative
Pleomorphic adenoma- myochondroid/chondroid stroma
What is the prognosis of polymorphous low grade adenocarcinoma?
Prognosis is somewhat unpredictable- not as low grade as other low grade tumours
What is adenocarcinoma NOS?
Tumours that do not fit into recognised types
Usually in parotid
What are the characteristics of adenocarcinoma NOS?
Infiltrating neoplasms, showing some glandular or ductal structures
How are adenocarcinoma NOS graded?
Graded according to duct number and epithelial atypia.
Few ducts and solid is high grade
Which major salivary glands are most commonly affected by tumours?
Parotid-90%
Submandibular-10%
Sublingual almost never
Which minor salivary glands are most commonly affected?
Palate-55%
Upper lip-20%
Lower lip-rare
Other parts-15%
Where does pleomorphic adenoma affect most?
Parotid- 60-65%
Minor-45%
What are the symptoms of pleomorphic adenoma?
Slow growing
Painless
Rubbery swelling
What is the lining of pleomorphic adenoma?
May be encapsulated, or incompletely
This means they can form intra or extracapsular nodules so excise through surgical margin, not through cleavage plane
What is the histology of pleomorphic adenoma?
- Varied epithelial and stromal patterns
- Epithelial and myoepithelial cells form sheets, strands and ducts in a myxoid/mucoid chondroid or fibrous stroma
- Plamacytoid pattern
- Squamous metaplasia
- May have stromal hyalinisation
Which types of pleomorphic adenoma are more likely to recur or transform?
Solid ones more likely to transform
Myxoid neoplasms more likely to recur
What is myoepithelioma?
A rare benign tumour of myoepithelial cells
50 years- women
Where does myoepithelioma affect most?
Minor salivary glands- primarily palate
Can affect parotid and occasionally submandibular
What is the histology of myoepithelioma?
Solid
Spindle cells
Epithelioid cells and clear cells
Plasmacytoid pattern
No ductal structures
S100 protein positive
What does a plasmacytoid pattern look like?
Eccentric nuclei
Abundant eosinophilic cytoplasm
What are the 4 types of myoepithelioma?
Plasmacytoid
Spindle
Recticular- ribbons of ME cells
Clear- uniform sheets of cells
Where is a Warthin tumour found?
Almost always in parotid
Between 60 and 70
80% multifocal- superficial parotidectomy
5-10%- bilateral or synchronous
What is the histology of warthin tumour?
- Glandular
- Often multiple cystic structures (papillary)
- Lined by eosinophilic epithelium- 2 layers, cuboidal and columnar rich in abnormal mitochondria
- Stroma with lymphoid tissue
What is the origin of warthin tumour?
Salivary duct epithelium entrapped in lymph nodes
What does warthin tumour look similar to?
Cystadenoma but without the lymphoid elements
What does the bilayer look like in warthins tumour?
Columnar cells have hyperchromatic nuclei that is aligned towards the luminal aspect.
Cuboidal cells have vesicular nuclei
Where are basal cell adenomas found?
70% parotid
20% upper lip
What is the histology of basal cell adenoma?
Uniform
Prominent
Basaloid cells
Basement membrane like structure
No mucoid stroma
What is the lining of basal cell adenoma?
They are encapsulated
What can basal cell adenoma transform to?
Basal cell adenocarcinoma
What is basal cell adenoma often seen with?
Other dermal tumours such as cylindroma, tricoepithelioma, eccrine spiradenoma- may be inherited predispostion
What are the 4 patterns of basal cell adenoma?
Solid- basaloid cells with peripheral palisading
Trabecular- loose fibrous stroma
Tubular
Membranous- distinct hyaline band
What can be used for immunohistochemistry in basal cell adenoma?
Keratin highlights inner luminal aspect
P63- basal cells
SMA- myoepithelial cells and BM zone
CD117 luminal cells
Where does oncocytoma affect most?
Parotid
Over 60
What can oncocytoma be confused with?
Oncocytic hyperplasia- ageing change- difficult to distinguish
What is the histology of oncocytoma?
- Polyhedral faintly granular eosinophilic cells
- Small dark nuclei
- Oncocytes have small dark nuclei- centrally placed with or without nucleoli
Where is canalicular found?
Almost all cases in upper lip
What is the histology of canalicular adenoma?
Columnar epithelial cells arranged in anastomosing bi-layer strands- beading pattern
Loose, highly vascular stroma
What is a ductal papilloma?
Rare tumour from excretory ducts
What is the endophytic ductal papilloma like?
Inverted ductal papilloma
Cuboidal to columnar cells seen on luminal aspect
Scattered mucous cells
Microcyst formation
What is exophytic ductal papilloma?
Intraductal papilloma
Luminal papillary proliferation
Fibrovascular cores
Microcysts
What is endophytic and exophytic ductal papilloma?
Sialadenoma papilliferum
Surface papillary squamous proliferation
Papillary hyperplasia
Adenomatous proliferation
Cuboidal luminal cells with spindle nuclei
