Parotid tumours (brief)

Question 1

How common is it?

Answer 1

Salivary gland tumours are rare, accounting for 0.4% of malignancies. 80% arise in the parotid gland.

Question 2

What causes it?

Answer 2

adenoma. 80% of benign parotid tumours. M:F 1:1. Peak incidence 30-50yr. Composed of epithelial cells that form a mucous matrix. Grows slowly and has no true capsule so that it can protrude into local tissue. Local extension can be widespread. Malignant change may develop in 10-30yrs.

Warthin’s tumour (adenolymphoma): Usually affects men >50yr. Benign and presents as a slow growing soft. Pleiomorphic swelling. Successfully treated by wide local excision.

Malignant tumours: Mucoepidermoid is low grade and slow. Cylindroma, rare, slow growing, eventual facial nerve involvement. Acinic cell carcinoma, slow growing but may met unexpectedly. SCC, adenocarcinomas and undifferentiated carcinomas are generally high grade malignant tumours.

Question 3

How does it present?

Answer 3

Slow growing lump in the infected gland. Pain, anaesthesia or trismus and facial palsy imply malignancy.

Question 4

Investigations

Answer 4

CT v useful, also may help differentiate between stones, inflammation and tumour.

MRI scanning offers the most sensitive investigation for assessment of local invasion and involvement of surrounding structures.

Question 5

Treatment

Answer 5

Excision