MEDIC : Parotid Tumours

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 tumours are benign and of these 80% are called pleomorphic adenomas.



Classification of parotid tumours:
1. Adenoma
A) Pleomorphic

• Any age, no gender predilection
• 75% of all parotid tumours
• Over 60 years of age

 


B) Warthin's tumour

• Over 60 years
• Male to female ratio is 4:1

2. Carcinomas

• Acinic cell Carcinoma: Low grade malignancy
• Adenoid Cystic carcinoma: Commonly seen in USA. Invariably fatal due to perineural spread and pulmonary metastasis
• Adenocarcinoma and Squamous Cell Carcinoma: Both have poor prognosis. Very rare. 25% have 5 year survival

3. Non epithelial

• Hemangioma
• Lymphangioma
• Neurofibroma
• Neurilemma
• Mostly infants affected. Frequent spontaneous regression of any gland affected in this group.

4. Malignant lymphoma
5. Unclassified tumour


What are the characteristic features of parotid tumours?

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

What are the criteria indicating malignant change in mixed parotid tumour?

• Sudden and rapid increase in size
• Painless tumour becomes painful and tender
• Feels stony hard
• Growth becomes fixed to the deeper structures e.g. masseter, mandible
• Overlying skin may become fixed to the swelling and looks and feels reddish blue and hot
• Evidence of facial nerve involvement causing asymmetry of face and difficulty in closing the eye
• Areas of anaesthesia over the skin
• Jaw movements become restrained
• 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 tumours?
Outlined here is the treatment of parotid tumours:

• 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
• Lipoma
• External carotid aneurysm
• Pre- Auricular lymph node 

References: 
1) http://specialist-ent.com/throat/parotid-tumours.aspx

2) google pictures

Example shortcase ENT posting : (what should student do)

1) General 

• Look at the patient and greet him / her

•Explain to the patient that you are going to examine him / her

•Ask if there is any tender parts so that you will not hurt the patient

2 )Inspection

–Surgical scars

–Punctum

–Skin changes / inflammation

3) Palpation

–Increased warmth

–Tenderness

–Surface

–Edge

–Mobility

–Solid / cystic

–Fixed to underlying muscle or overlying skin

4) Do a Transilluminate test

5) Ascultate for carotid bruit

6) Test facial nerve 

Questions that always doctor ask after finish do examination!

•Give Differential Diagnoses

–Pleomorphic adenoma

–Warthin’s  tumour

–Adenoid cystic carcinoma

–Lymph node enlargement within Parotid

–TB Lympadenitis

•Parotid tumour: Investigation and treatment

•Name one diagnostic investigation?

–Fine needle aspiration

•How will you treat this condition?

–Parotidectomy

•Superficial parotidectomy if benign

•Total parotidectomy if malignant

Source : Prof Sani Slide presentation.

 

p/s: just sharing. not a pirates of carribean~ehhe. ^^,