Pathology of Salivary Gland Tumours

Question 1

name 4 reasons for a change in gland size

Answer 1

• secretion retention (mucocele, obstruction)
• chronic sialadenitis (infection e.g mumps)
• gland hyperplasia
• neoplasms

Question 2

are salivary gland tumours common?
are they usually malignant?
what glands are commonly affected?

Answer 2

uncommon but not rare
75% of tumours are benign
parotid tumours are majority
as major glands decrease in size, incidence decreases but malignancy increases

Question 3

what areas of the mouth may minor salivary gland tumours commonly be seen

Answer 3

junction of hard/ soft palate
upper lip/ cheek

Question 4

name 3 methods of taking a biopsy of a salivary gland swelling

Answer 4

• fine needle aspirate (may be ultrasound guided)
• core biopsy (rarely done for salivary tumours)
• incisional biopsy

Question 5

why is diagnosis of salivary gland tumours difficult (4)

Answer 5

• large number of different types
• common features between types
• not all tumours fit into classification
• large variation in tissues present in tumour - each slide may be different

Question 6

what is the most common salivary gland tumour

Answer 6

pleomorphic adenoma

Question 7

pleomorphic adenoma

Answer 7

makes up 75% of all salivary gland tumours, most commonly affects the parotid
benign
treatment is wide local excision but recurrence is common
risk of malignant transformation = 5%

Question 8

histology of pleomorphic adenomas

Answer 8

pleopmorphic refers to varied histology within tumour - varying types of tissues and cells e.g duct epithelium and myoepithelial cells

fibrous capsule may be present but may be incomplete

Question 9

warthins tumour

Answer 9

15% of salivary gland tumours
most commonly in parotid
benign
treated by excision, recurrence is rare

Question 9

what is an adenolymphoma also called

Answer 9

Warthins tumour

Question 10

what is a strange feature of warthins tumours

Answer 10

may appear bilateral
(common in smokers)

Question 11

histological appearance of warthins tumours

Answer 11

cystic spaces lined by 2 layers of pink epithelium
also lymphoid tissue present
has a connective tissue capsule

Question 12

what are the two main types of salivary gland carcinomas

Answer 12

adenoid cystic carcinoma
mucoepidermoid carcinoma

Question 13

what histological stain is good for identifying mucous secreting cells

Answer 13

alcian blue

Question 14

are salivary gland carcinomas more common in major or minor glands

Answer 14

minor

Question 15

why are adenoid cystic carcinomas difficult to eradicate

Answer 15

due to perineural infiltration (spreads along nerves)

Question 16

name 2 potential patterns of an adenoid cystic carcinoma

Answer 16

tubular
solid
cribriform (swiss cheese)

Question 17

what 2 cell types are involved in mucoepidermoid carcinomas

Answer 17

squamous (epidermoid)
glandular (muco)