Salivary gland pathology Flashcards
What is the most common site for almost all tumours?
Parotid gland
Are most parotid gland tumours benign or malignant?
Benign
Are most small salivary gland tumours benign or malignant?
Malignant
What are some benign salivary gland tumours?
Pleomorphic adenoma (Most common)
Warthin’s tumour
What are some malignant salivary gland tumours?
Mucoepidermoid carcinoma
Adenoid cystic carcinoma
Who is most at risk of pleomorphic adenoma?
- female
- 3-6th decade
- Radiation exposure
Describe the macroscopic appearance of pleomorphic adenoma
Well circumscribed, light tan to grey
Describe the microscopic appearance of pleomorphic adenoma
Highly variable epithelial and myoepithelial cells in chondromyxoid stroma
What are some risk factors of Warthin’s tumour?
- Male
- Over 50
- Smoking
Describe the macroscopic features of Warthin’s tumour
Well circumscribed, light grey, cystic
Bilateral and multi-centric
Describe the microscopic appearance of Warthin’s tumour
Bilayered oncocytic epithelium with lymphoid stroma
When should a malignant salivary gland tumour be suspected?
Young and a painful mass
What is the prognosis of low grade mucoepidermoid carcinoma?
> 90% 5 year survival
What is the prognosis of high grade mucoepidermoid carcinoma?
< 60% survival
What genetic mutation is associated with mucoepidermoid carcinoma?
MECT1-MAML2 fusion
Describe the macroscopic appearance of mucoepidermoid carcinoma?
Can be well circumscribed or infiltrative
Describe the microscopic appearance of mucoepidermoid carcinoma?
Variable mix of squamous, mucous and intermediate cells, with solid and cystic components
Where do adenoid cystic carcinomas affect?
Most commonly the parotid, but are also the most common malignant tumours of the palate
What is the prognosis of adenoid cystic carcinoma?
50-70% 10-year survival
What is a possible complication of adenoid cystic carcinoma?
Perineural invasion - associated pain or loss of function
Describe the macroscopic appearance of adenoid cystic carcinoma
Greyish/white infiltrative mass
Describe the microscopic appearance of adenoid cystic carcinoma
Small, uniform cells with little cytoplasm in solid, tubular or cribiform plate
How do salivary gland tumours present?
Mass in the affected gland which may or may not have been present for a long time
Signs of CN VII (facial nerve) damage e.g. facial nerve palsy are associated with malignant parotid tumours
What is shown?
Parotid gland tumour
What are some investigations required in salivary gland tumours?
- US
- FNA
- Staging
- CT - local relations
- MRI - deep lobe of parotid, relations with CN-VII
How are salivary gland tumours managed?
- Salivary gland tumours are nearly always resected e.g. superficial or total parotidectomy
- Usually in their early stages it is not possible to distinguish a benign tumour from a malignant one
- There is a risk of malignant transformation of adenoma if left alone
What are some structures at risk in cases of parotidectomy?
Facial nerve
Retromandibular vein
External carotid artery
What is infection of the salivary glands known as?
Sialadenitis
What are some causes of sialadenitis?
- Viral (mumps - paramyxoma virus)
- Bacterial
What is stone formation in the salivary glands known as?
Sialolithiasis
