Salivary Gland Tumours

Question 1

For what reasons might someone have an enlarged salivary gland?

Answer 1

Duct obstruction- sialolith
Duct dilatation
Duct stricture
Chronic sialadentitis
Hyperplasia- Sialosis, Sjogren’s
Viral infection- HIV, EBV
Tumour

Question 2

What gland is most likely to give a neurological change?

Answer 2

Parotid- facial nerve passes through here.

Also have the external carotid artery and retromandibular vein.

Question 3

Are most salivary glands benign or malignant?

Answer 3

Mostly benign- about 75% are benign.

Most are found in the parotid gland but as the gland gets smaller, the most likely the tumour is to be malignant.

Question 4

What are the clinical features of a salivary gland tumour in a major gland?

Answer 4

Asymmetry
Obstruction
Pain
Facial palsy

Question 5

What are the clinical features of a salivary gland tumour in a minor gland?

Answer 5

Junction of hard/soft palate
Upper lip/cheek
Ulcerate late (malignant)

Question 6

What special investigations would you request if you see a salivary gland swelling?

Answer 6

Ultrasound guided fine needle aspirate.

Core biopsy

Incisional biopsy

Question 7

What are some of the problems you may encounter with diagnosis of a salivary gland tumour?

Answer 7

Lots of different types of salivary gland tumour

Common features between types

Variation within a tumour because tissues originate from different stem cell lines so pathology may be complex.

Not all tumours fit the classification

Immunohistochemistry may be needed to differentiate many of these tumours

Question 8

Give examples of some benign salivary gland tumours.

Answer 8

Pleomorphic adenoma.

Warthin’s Tumour

Question 9

What is a Pleomprohic Adenoma?

Answer 9

Benign salivary tumour that originates from ductal epithelium, which proliferates to contribute to duct-like spaces, sheets of epi- thelial cells and sometimes areas of squamous metaplasia

Question 10

What is the typical presentation of pleomorphic adenoma?

Answer 10

Usually in the parotid.

Slow growth, rubbery, lobulated growth with normal overlying skin but if it is intra-orally then it sometimes appears blue.

Question 11

Describe the histological findings of a pleomorphic adenoma?

Answer 11

Duct epithelium- duct like structures within.

Myoepithelial cells

Myxomatous tissue

Thin capsule that may also be incomplete- tumour tissue can grow out into the surrounding area.

Question 12

What is the treatment for a pleomorphic adenoma?

Answer 12

Wide local excision because there is a risk of recurrence.

Question 13

What clinical signs would suggest malignant transformation?

Answer 13

Rapid growth

Pain

Fixation to deep tissues

Facial palsy

Question 14

What is a Warthin’s tumour?

Answer 14

Benign tumour usually found in the parotid.

Occasionally multiple/bilateral.

Question 15

Describe the histological features of a Warthin’s tumour.

Answer 15

Cystic spaces

Oncocytic epithelium.

Lymphoid tissues

Question 16

What is the treatment for a Warthin’s tumour?

Answer 16

Excision

Question 17

Give examples of salary gland carcinomas.

Answer 17

Adenoid cystic carcinoma

Mucoepidermoid carcinoma

Acinic cell carcinoma

Polymorphous adenocarcinoma

Question 18

Where are adenoid cystic carcinomas usually found?

Answer 18

In minor salivary glands

Question 19

What is an adenoid cystic carcinoma?

Answer 19

Slow growing malignant tumour with metastatic potential.
- usually into the blood and then the lungs.

Usually painless initially but gets painful once it starts to infiltrate the nerve.
- this makes it difficult to treat.

Question 20

Describe the histological presentation of an adenoid cystic carcinoma.

Answer 20

Cystic spaces

Malignant cells

Nerves within the same space.

Rounded islands of small darkly staining cells surround- ing multiple clear areas of varying size (Swiss-cheese appearance) are characteristic

Question 21

What is a mucoepidermoid tumour?

Answer 21

Slow growing tumour that can be benign or malignant.

Question 22

What are the histological characteristics of mucoepidermoid carcinoma?

Answer 22

2 different cell types
- squamous and glandular.

Mucous secreting cells

Squamous epithelium

Cystic spaces

Question 23

How are malignant salivary gland tumours graded?

Answer 23

Cystic or solid
- Solid areas have poorer prognosis.

Neural invasion

Presence of necrosis

Mitoses