Parotid Cancer

Excerpt

Salivary gland neoplasms may be benign or malignant, and malignant tumors can be primary or metastatic. Due to the epithelial and the non-epithelial histology of the affected organ, many histological types of parotid tumors are possible, although some are rare. Salivary gland tumors are characterized by diverse histological appearances and variable biological behavior. The distinction between tumor types can be difficult, particularly based on material from fine-needle aspiration (FNA). There are several other aspects of salivary gland tumors that make them interesting. The commonest benign tumor (pleomorphic adenoma) has a malignant transformation potential, and, although considered benign, there is a propensity for recurrence after treatment. It is not surprising that with such a wealth of pathology, clinical features, investigation issues, and contentious treatment options that salivary gland neoplasms are regularly used in clinical examinations.

Malignant salivary gland tumors usually present after the 6th decade of life, whereas benign lesions present in the 4-5th decade of life. Benign lesions tend to be more common in women, but malignant lesions tend to occur with equal frequency in both genders. The majority of salivary gland tumors occur in the parotid, about 10% occur in the submandibular gland, and less than 4% occur in the minor salivary glands. Most parotid gland tumors are benign, of which the most important is the pleomorphic adenoma. On the other hand, lesions occurring in the submandibular gland and the minor salivary glands are more likely to be malignant.

Mortality from salivary gland tumors depends on the stage. Five-year survival averages about 70%.