20. Neoplastic salivary gland disease

Question 1

What are the 5 malignant salivary gland tumours?

Answer 1

Mucoepidermoid carcinoma
Acinic cell carcinoma
Adenoid cystic carcinoma
Carcinoma ex pleomorphic adenoma
Polymorphous low grade adenocarcinoma

Question 2

Where does mucoepidermoid carcinoma affect most?

Answer 2

Commonest SG tumour
Parotid and palate

Question 3

What are the features of mucoepidermoid carcinoma?

Answer 3

Poorly circumscribed
Invasive
Cystic formation cell
3 cell types

Question 4

What is the first cell type of mucoepidermoid carcinoma?

Answer 4

Squamous/epidermoid cells- intercellular bridges, keratinisation very rare, solid or cystic

Question 5

What is the second cell type in mucoepidermoid carcinoma?

Answer 5

Mucous producing cells- PAS staining, solid or cystic, cuboidal or columnar goblet like, cyst might break down inducing a granulomatous reaction

Question 6

What is the third cell in mucoepidermoid carcinoma?

Answer 6

Small, dark stained nuclei

Question 7

What is low grade mucoepidermoid carcinoma?

Answer 7

Survival 5 years- 90%
More than 50% mucous cells
Cystic spaces
More circumscribed

Question 8

What is high grade mucoepidermoid carcinoma?

Answer 8

5 year survival is 70%
More squamous and intermediate cells, necrosis and haemorrhage

Question 9

Where does acinic cell carcinoma affect most?

Answer 9

Low grade tumour
80% affects parotid

Question 10

What type of cells do acinic cell carcinoma contain?

Answer 10

Shows some cytological differentiation towards acinar cells, but a wide range of histological patterns.
Solid, microcystic, papillary-cystic, follicular

Question 11

What is the histology of acinic cell carcinoma?

Answer 11

Sheets groups of large polygonal acinar cells
Granular cytoplasms- PAS positive
Vacuolated cells
Intercalated duct like cells
Lymphoid infiltrate in the stroma

Question 12

What is the survival rate of acinar cell carcinoma?

Answer 12

Well differentiated- 80 to 100%
Poorly differentiated- 65%

Question 13

Where does adenoid cystic carcinoma affect most?

Answer 13

Middle age/elderly patients
More common in minor salivary glands

Question 14

What are the symptoms of adenoid cystic carcinoma?

Answer 14

Slow enlarging
Pain
Ulceration
Facial palsy in parotid

Question 15

What are the 3 histological patterns of adenoid cystic carcinoma?

Answer 15

Cribriform- swiss cheese, basement membrane like material
Tubular- surrounded by desmoplastic stroma
Solid

Question 16

What are the cell types in adenoid cystic carcinoma?

Answer 16

Duct lining cells- small, basophilic forming pseudo/cysts
Myoepithelial cells

Question 17

Where can adenoid cystic carcinoma invade into?

Answer 17

Perineural and perivascular invasion without stromal reaction
In bone it spreads via marrow spaces
Recurrence is common

Question 18

What is the survival rate of adenoid cystic carcinoma?

Answer 18

Survival 5 years- 75%
10-40%
20-20%

Question 19

Which type of adenoid cystic carcinoma has the most perineural invasion?

Answer 19

Solid tumour type
Has large nests of cells with high nuclear to cytoplasm ratio

Question 20

What can be used to stain in adenoid cystic carcinoma?

Answer 20

Alcian blue- highlights the pseudocystic glycosaminoglycan material

Question 21

Where is carcinoma ex pleomorphic adenoma mostly found?

Answer 21

Arises from pleomorphic adenoma from mostly parotid which have been present a long time
They turn into adenocarcinoma or undifferentiated carcinoma

Question 22

When is carcinoma ex pleomorphic adenoma mostly found?

Answer 22

Peak of incidence is 10 years later than peak for pleomorphic adenoma

Question 23

Where can carcinoma ex-pleomorphic adenoma metastastise to?

Answer 23

Lymph nodes
Lungs
Bone

Question 24

What is the prognosis of carcinoma ex pleomorphic adenoma like?

Answer 24

If still inside the capsule of pleomorphic adenoma then it is good prognosis, otherwise poor

Question 25

Where is polymorphous low grade adenocarcinoma mostly found?

Answer 25

Almost exclusively in minor SG in palate

Question 26

What are the growth patterns of polymorphous low grade adenocarcinoma?

Answer 26

Trabecular Cribriform Papillary Lobular

Question 27

What is the histology of polymorphous low grade adenocarcinoma?

Answer 27

Concentric neurotropism Mucinosis in the stroma Encasement of benign residual salivary glands

Question 28

What is the differential diagnosis for polymorphous low grade carcinoma?

Answer 28

Adenoid cystic carcinoma- hyperchromatic nuclei, more infiltrative Pleomorphic adenoma- myochondroid/chondroid stroma

Question 29

What is the prognosis of polymorphous low grade adenocarcinoma?

Answer 29

Prognosis is somewhat unpredictable- not as low grade as other low grade tumours

Question 30

What is adenocarcinoma NOS?

Answer 30

Tumours that do not fit into recognised types Usually in parotid

Question 31

What are the characteristics of adenocarcinoma NOS?

Answer 31

Infiltrating neoplasms, showing some glandular or ductal structures

Question 32

How are adenocarcinoma NOS graded?

Answer 32

Graded according to duct number and epithelial atypia. Few ducts and solid is high grade

Question 33

Which major salivary glands are most commonly affected by tumours?

Answer 33

Parotid-90% Submandibular-10% Sublingual almost never

Question 34

Which minor salivary glands are most commonly affected?

Answer 34

Palate-55% Upper lip-20% Lower lip-rare Other parts-15%

Question 35

Where does pleomorphic adenoma affect most?

Answer 35

Parotid- 60-65% Minor-45%

Question 36

What are the symptoms of pleomorphic adenoma?

Answer 36

Slow growing Painless Rubbery swelling

Question 37

What is the lining of pleomorphic adenoma?

Answer 37

May be encapsulated, or incompletely This means they can form intra or extracapsular nodules so excise through surgical margin, not through cleavage plane

Question 38

What is the histology of pleomorphic adenoma?

Answer 38

1. Varied epithelial and stromal patterns 2. Epithelial and myoepithelial cells form sheets, strands and ducts in a myxoid/mucoid chondroid or fibrous stroma 3. Plamacytoid pattern 4. Squamous metaplasia 5. May have stromal hyalinisation

Question 39

Which types of pleomorphic adenoma are more likely to recur or transform?

Answer 39

Solid ones more likely to transform Myxoid neoplasms more likely to recur

Question 40

What is myoepithelioma?

Answer 40

A rare benign tumour of myoepithelial cells 50 years- women

Question 41

Where does myoepithelioma affect most?

Answer 41

Minor salivary glands- primarily palate Can affect parotid and occasionally submandibular

Question 42

What is the histology of myoepithelioma?

Answer 42

Solid Spindle cells Epithelioid cells and clear cells Plasmacytoid pattern No ductal structures S100 protein positive

Question 43

What does a plasmacytoid pattern look like?

Answer 43

Eccentric nuclei Abundant eosinophilic cytoplasm

Question 44

What are the 4 types of myoepithelioma?

Answer 44

Plasmacytoid Spindle Recticular- ribbons of ME cells Clear- uniform sheets of cells

Question 45

Where is a Warthin tumour found?

Answer 45

Almost always in parotid Between 60 and 70 80% multifocal- superficial parotidectomy 5-10%- bilateral or synchronous

Question 46

What is the histology of warthin tumour?

Answer 46

1. Glandular 2. Often multiple cystic structures (papillary) 3. Lined by eosinophilic epithelium- 2 layers, cuboidal and columnar rich in abnormal mitochondria 4. Stroma with lymphoid tissue

Question 47

What is the origin of warthin tumour?

Answer 47

Salivary duct epithelium entrapped in lymph nodes

Question 48

What does warthin tumour look similar to?

Answer 48

Cystadenoma but without the lymphoid elements

Question 49

What does the bilayer look like in warthins tumour?

Answer 49

Columnar cells have hyperchromatic nuclei that is aligned towards the luminal aspect. Cuboidal cells have vesicular nuclei

Question 50

Where are basal cell adenomas found?

Answer 50

70% parotid 20% upper lip

Question 51

What is the histology of basal cell adenoma?

Answer 51

Uniform Prominent Basaloid cells Basement membrane like structure No mucoid stroma

Question 52

What is the lining of basal cell adenoma?

Answer 52

They are encapsulated

Question 53

What can basal cell adenoma transform to?

Answer 53

Basal cell adenocarcinoma

Question 54

What is basal cell adenoma often seen with?

Answer 54

Other dermal tumours such as cylindroma, tricoepithelioma, eccrine spiradenoma- may be inherited predispostion

Question 55

What are the 4 patterns of basal cell adenoma?

Answer 55

Solid- basaloid cells with peripheral palisading Trabecular- loose fibrous stroma Tubular Membranous- distinct hyaline band

Question 56

What can be used for immunohistochemistry in basal cell adenoma?

Answer 56

Keratin highlights inner luminal aspect P63- basal cells SMA- myoepithelial cells and BM zone CD117 luminal cells

Question 57

Where does oncocytoma affect most?

Answer 57

Parotid Over 60

Question 58

What can oncocytoma be confused with?

Answer 58

Oncocytic hyperplasia- ageing change- difficult to distinguish

Question 59

What is the histology of oncocytoma?

Answer 59

1. Polyhedral faintly granular eosinophilic cells 2. Small dark nuclei 3. Oncocytes have small dark nuclei- centrally placed with or without nucleoli

Question 60

Where is canalicular found?

Answer 60

Almost all cases in upper lip

Question 61

What is the histology of canalicular adenoma?

Answer 61

Columnar epithelial cells arranged in anastomosing bi-layer strands- beading pattern Loose, highly vascular stroma

Question 62

What is a ductal papilloma?

Answer 62

Rare tumour from excretory ducts

Question 63

What is the endophytic ductal papilloma like?

Answer 63

Inverted ductal papilloma Cuboidal to columnar cells seen on luminal aspect Scattered mucous cells Microcyst formation

Question 64

What is exophytic ductal papilloma?

Answer 64

Intraductal papilloma Luminal papillary proliferation Fibrovascular cores Microcysts

Question 65

What is endophytic and exophytic ductal papilloma?

Answer 65

Sialadenoma papilliferum Surface papillary squamous proliferation Papillary hyperplasia Adenomatous proliferation Cuboidal luminal cells with spindle nuclei