Salivary Gland Surgery
About The Salivary Glands.
There are three paired glands in the head and neck that produce
saliva. The parotid glands are the largest and overlie the angle of
the jaw in front of the ear. A tube, known as Stensen's duct,
drains saliva from the glands into the mouth. The submandibular
glands lie deep to the lower jaw and their ducts, which are the
longest and narrowest of all the salivary glands, enter the mouth
under the front of the tongue. The sublingual glands lie deep to
the lining of the mouth on each side of the tongue, these glands
have many short ducts that enter the mouth directly through the
In addition to these major glands there are hundreds of minor
salivary glands throughout the lining of the mouth and throat with
most on the lips and palate. All of these glands produce saliva in
response to food being placed in the mouth.
Salivary Gland Tumours
Benign tumours are the most common and present as a firm to
hard, mobile, regular mass without involvement of overlying or deep
structures. They tend to enlarge slowly and progressively and they
are painless. Malignant tumours on the other hand can enlarge
rapidly, they can become fixed to underlying structures or the
subcutaneous tissue and skin overlying the gland. They can involve
nerves associated with the salivary gland and can spread to lymph
nodes in the neck.
Tumours in the parotid gland are 80% likely to be benign,
whereas submandibular tumours are only 50% likely to be non
cancerous. In the sublingual gland and minor salivary glands most
neoplasms are malignant.
1. Parotid Gland Tumours
Most lumps of the parotid are benign. The most common is the
pleomorphic adenoma followed by Warthins Tumour. They present as a
firm mobile mass in the face or upper neck. They can become quite
large if left to grow. The majority 90% of these tumours occur in
the superficial aspect of the gland (lateral to the nerve of the
face) occasionally , however, these tumours occur in the deep part
of the gland, behind the jaw. Benign salivary gland tumours
generally do not cause facial weakness. Pleomorphic adenomas have a
risk of malignant change over a long period of time.
The most common malignant tumour (70%) of the parotid gland in
Australia is spread of skin cancer involving intra-parotid lymph
nodes. These tend to be aggressive tumours that may also spread to
lymph nodes in the neck. There is usually a history of removal of a
skin cancer or melanoma on the scalp, ear, facial or temple skin in
the preceding two years. Occasionally a patient will present with a
lump that originates in the parotid. These also tend to be hard and
irregular and can be fixed to deep structures or to the overlying
skin causing discolouration or ulceration. They can be multiple and
there can be palpable lymph nodes in the neck most frequently in
the upper deep cervical region.
2. Submandibular Tumours
Tumours in the submandibular gland are equally likely to be
benign or malignant. They usually present as a firm to hard mass
within the gland. Usually mobile and tend only to become fixed and
involve nerves if malignant. Skin cancers and melanoma can spread
to nodes in this region also, however the lymph nodes are not
within the substance of the gland like the parotid gland but
attached to the fascia around the gland.
Minor Salivary Gland Tumours Uncommon and more
likely (50%-80%) to be malignant. Present as a submucosal lump on
the oral or nasal mucosa. Most common on the palate, lip, tongue
and floor of mouth.
Clinical assessment is very important in the diagnosis of
salivary gland masses. Investigations are not always necessary and
in fact can lead to a false sense of security and adoption of
conservative management when surgery is required. There is however
a role for investigating some parotid and other salivary gland
Overall physical examination, imaging and Fine Needle Aspirate
(FNA) is adequate for a diagnosis in approximately 95% of
Surgery is required for all salivary tumours with the only
exceptions being a probable benign tumour in an older patient who
is reluctant for surgery or is an anaesthetic risk. Even with a
tumour that is suspected to be benign on investigation the
rationale for operating is threefold. 1. All tumours progress and
the risk to the surrounding structures are greater with larger
tumours. 2. It can be difficult to diagnose malignancy clinically
and there is a false negative rate with needle biopsy. 3. Benign
salivary tumours are at risk of malignant transformation.
Parotid Gland Surgery (Parotidectomy)
The operation is performed under general anaesthetic. An
incision is made in front of the ear it passes down behind the ear
lobe and then curves forward into the neck. It is a similar
incision to that used for a cosmetic facelift, it heals well and is
rarely noticeable. The wound is carefully closed at the end of the
operation and a suction drain is placed to remove any blood or
fluid that would otherwise collect under the skin.
The operation varies depending on the type, position and size of
the tumour. For the majority of parotid tumours only a portion of
the gland containing the tumour is removed. If the tumour involves
the deep lobe, then a greater portion is removed. With some deep
lobe parotid tumours the jaw may need to be opened to allow access
to the deep part of the tumour. Occasionally and only with advanced
malignant tumours the facial nerve needs to be removed.
With metastatic skin malignancy and some high grade salivary
cancers where lymph nodes are involved removal of neck lymph nodes
is also necessary. This operation is called a neck dissection.
Post operatively one to two nights in hospital are required and
normal activities can be resumed in one to two weeks.
Submandibular Gland Surgery
This operation is also best performed under general anaesthetic.
The incision is made in the neck about two finger breadths below
the lower border of the jaw in a skin crease. The wound usually
heals very well and after a period is almost imperceptible. A drain
is also used in this operation.
The entire gland is removed also with a small portion of the
duct. If there is a malignant tumour a wider excision is often
required with removal of surrounding soft tissue or jaw bone
including muscle, lymph nodes and occasionally surrounding nerves.
In metastatic skin malignancy and some high-grade salivary cancers
with lymph node involvement removal of lymph nodes in the neck is
also necessary. This operation is called a neck dissection and is
explained in another article.
Post operatively one to two nights in hospital is usually
necessary and normal activities may often be resumed in one to two