Salivary glands
Primary salivary gland neoplasms
Primary salivary gland neoplasms-general
Author: F. Zahra Aly, M.D., Ph.D.
Last author update: 1 August 2011
Last staff update: 7 April 2021
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: Primary salivary gland neoplasms review[ptyp] free full text[sb]
Cite this page: Aly FZ. Primary salivary gland neoplasms-general. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/salivaryglandstumorsgeneral.html. Accessed April 19th, 2024.
Definition / general
- Risk factors: radiation exposure (atomic bomb survivors, radiation therapy, chemoradiation therapy) with mean latency after low dose radiation exposure of 11 years for malignant tumors and 21 years for benign tumors
- Alcohol and tobacco are NOT risk factors except for Warthin tumor (associated with smoking)
- Benign: pleomorphic adenoma (50%), Warthin tumor (5%), oncocytoma, basal cell adenoma, ductal papilloma
- Malignant: mucoepidermoid carcinoma (15%), polymorphous low grade adenocarcinoma (10%), acinic cell carcinoma, adenoid cystic carcinoma, malignant mixed tumor, squamous cell carcinoma (1%)
- Bilateral tumors: Warthin tumor is most common, also pleomorphic adenoma and acinic cell carcinoma
- 15% of parotid tumors are malignant, 40% elsewhere
- Children: pleomorphic adenoma most common but more often malignant; most common malignant tumors are mucoepidermoid carcinoma, adenoid cystic carcinoma, acinic cell carcinoma
- Regional lymph nodes: nodal metastases usually evident on initial clinical evaluation
- Low grade tumors rarely metastasize to regional nodes, high grade tumors often do; nodal involvement tends to be orderly from intraglandular to adjacent nodes to upper and midjugular nodes and occasionally to retropharyngeal nodes
- Bilateral nodal involvement is rare
- Metastases: usually to lungs
Sites
- > 90% arise in parotid gland, 5% in submandibular gland
- Deep parotid tumors may present as intraoral masses
- Sublingual tumors are rare and may be difficult to distinguish from minor salivary gland primary tumors of anterior floor of mouth
- Minor salivary gland tumors usually in hard palate (site with most glandular tissue); may arise in lymph nodes around salivary glands
Poor prognostic factors
- Postoperative recurrence, submandibular gland site, facial nerve paralysis, high grade tumor
Treatment
- Parotid gland tumors: superficial lobe tumors are treated with superficial / partial parotidectomy with preservation of facial nerve
- Total parotidectomy with sacrifice of facial nerve may be necessary if high grade or advanced tumor
- Neck dissection necessary if nodal involvement
- Submandibular tumors: total excision; often recur because of difficulty of getting good margins due to closeness of mandible
- Radiation therapy: for inoperable tumors
