Introduction

The Parotid gland is the salivary gland which is situated laterally near the mandible.
Approximately 75% of neoplasms of salivary glands occur in the parotid glands.
80% of Parotid tumors are benign and of these 80% are Pleomorphic adenomas.

Classification of Parotid tumors:

1. Adenoma:

a) Pleomorphic:

➣ 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.

➣ Consists 15% of all parotid tumors.

2.Carcinomas

a) Acinic cell Carcinoma: Low grade malignancy.

b) Adenoid Cystic carcinoma: Commonly seen in USA. Invariably fatal due to perineural spread and pulmonary metastasis.

c) Adenocarcinoma and Squamous Cell Carcinoma: Both have poor prognosis. Very rare. ( 25% have 5-year survival)

3. Non epithelial:

a) Hemangioma.

b) Lymphangioma.

c) Neurofibroma.

d) Neurilemma.

Mostly infants affected. Frequent spontaneous regression of any gland affected in this group.

4. Malignant lymphoma.

5. Unclassified tumour.

Right Parotid tumour.

Characteristic features:

1. All parotid neoplasms are radioresistant.
2. No formal biopsy should be performed in parotid tumors except in tumors of ectopic salivary gland e.g. palatal salivary gland.

Criteria of malignant change in mixed parotid tumor:

1. Sudden and rapid increase in size.
2. Painless tumor becomes painful and tender.
3. Feels stony hard.
4. Growth becomes fixed to the deeper structures e.g. masseter, mandible.
5. Overlying skin may become fixed to the swelling and looks and feels reddish blue and hot.
6. Evidence of facial nerve involvement causing asymmetry of face and difficulty in closing the eye.
7. Areas of anesthesia over the skin.

• 8. Jaw movements become restrained.
• 9. Veins over the swelling become prominent.
• 10. Enlargement of cervical lymph node.
• 11. There may be evidence of disseminated blood borne metastasis.

Treatment:

1. Benign: Superficial parotidectomy.
2. Malignant: Radical parotidectomy or total conservative parotidectomy.
3. Malignant metastatic lymph nodes may be treated by radical neck dissection or by radiotherapy.

Differential diagnosis of parotid swellings:

1. Winged mandible.
2. Masseteric hypertrophy.
3. Lipoma.
4. External carotid aneurysm.
5. Pre- Auricular lymph node.