Diagnosis & staging
Diagnosis
These are tests that may be used to diagnose this type of cancer.
- Physical examination by a physician or dentist
- Biopsy (usually a fine needle aspiration)
- CT (computed tomography) scan may be needed
For more information on tests used to diagnose cancer, see our Recommended Websites, Diagnostic Tests section.
Types and stages
Types
- Most salivary gland tumours are benign (seldom life-threatening and not likely to spread).
- Benign tumours may be present for years with very little change.
- Specific types of benign tumours are:
- Pleomorphic adenoma or mixed tumour, the most common salivary gland tumour, has a tendency to recur.
- Warthin tumour, the second most common salivary gland tumour, usually occurs in the parotid glands.
- Basal cell adenoma are rare and usually do not recur.
- Mucoepidermoid carcinomas are the most common malignant tumour of the salivary glands.
- Malignant tumours are classed as low grade (low risk) or high grade (high risk) according to cell type.
- High grade tumours include:
- Some mucoepidermoid carcinomas
- Malignant mixed tumours are carcinomas that have arisen from a benign pleomorphic adenoma
- Adenoid cystic carcinomas are the most common cancer of the minor salivary glands
- Salivary duct carcinoma, which is one of the most aggressive salivary tumours, frequently recurs or spreads to distant sites (metastasis)
- Oncocytic carcinoma also frequently recurs or spreads to distant sites
- Large cell carcinomas are very rare, aggressive tumours
- Low grade tumours include:
- Most mucoepidermoid carcinomas
- Acinic cell carcinomas, which usually start in the parotid glands
- Clear cell carcinomas, which rarely spread beyond the salivary glands
Stages
Staging describes the extent of a cancer. The TNM classification system is used as the standard around the world. In general a lower number in each category means a better prognosis. The stage of the cancer is used to plan the treatment.
T describes the site and size of the main tumour (primary)
N describes involvement of lymph nodes
M relates to whether the cancer has spread (presence or absence of distant metastases)
Stage T0
No evidence of a primary tumour
Stage T1
Tumour is less than 2 cm
Stage T2
Tumour is larger than 2 cm but less than 4 cm
Stage T3
Tumour is larger than 4 cm across and/or is spreading into nearby soft tissues
Stage T4a
Tumour is any size and is growing into nearby structures such as the jaw bone, skin, ear canal, and/or facial nerve. (Moderately advanced disease.)
Stage T4b
Tumour is any size and is growing into nearby structures such as the base of the skull or other bones nearby, or it surrounds the carotid artery. (Very advanced disease.)