The Parotid gland is the salivary gland which is situated laterally near the mandible. Approximately 75% of neoplasm of salivary glands occur in the parotid glands. 80% of parotid tumors are benign and of this 80 % are called pleomorphic adenomas.
Classification of parotid tumors:
● Any age, no gender predilection
● 75% of all parotid tumors
● Over 60 years of age
B) Warthin’s tumor
● Over 60 years
● Male to female ratio is 4:1
● Acinic cell Carcinoma: Low-grade malignancy
● Adenoid Cystic Carcinoma: Commonly seen in the USA. Invariably fatal due to perineural spread and pulmonary metastasis
● Adenocarcinoma and Squamous Cell Carcinoma: Both have a poor prognosis. Very rare. 25% have 5-year survival
● Mostly infants affected. Frequent spontaneous regression of any gland affected in this group.
5.An unclassified tumor
● All parotid neoplasms are radioresistant
● No formal biopsy should be performed in parotid tumors except in tumors of ectopic salivary gland e.g. palatal salivary gland
What are the criteria indicating the malignant change in the mixed parotid tumor?
● Sudden and rapid increase in size
● A painless tumor becomes painful and tender
● Feels stony hard
● Growth becomes fixed to the deeper structures e.g. masseter, mandible
● The overlying skin may become fixed to the swelling and looks and feels reddish blue and hot
● Areas of anesthesia over the skin
● Jaw movements become restrained
● Evidence of facial nerve involvement causing asymmetry of face and difficulty in closing the eye
● Veins over the swelling become prominent
● Enlargement of cervical lymph node
● There may be evidence of disseminated blood-borne metastasis
What is the treatment of parotid tumors?
Outlined here is the treatment of parotid tumors:
● Benign: Superficial parotidectomy.
● Malignant: Radical parotidectomy or total conservative parotidectomy.
● Malignant metastatic lymph nodes may be treated by radical neck dissection or by radiotherapy.
What is the differential diagnosis of parotid swelling?
Differential diagnosis of parotid swellings:
● Winged mandible
● Masseteric hypertrophy
● External carotid aneurysm
● Pre- Auricular lymph node