Acinic Cell Carcinoma is a rare
malignancy accounting for 1 to 6% of all salivary gland tumors and 15% of all
malignant tumors in parotid gland. Most acinic cell carcinomas start in the
parotid gland. They tend to be slow growing and mainly occur at a younger age
than most other salivary gland cancers. They are usually low grade, but how far
they have grown into nearby tissue is a better predictor of a patient’s
outlook.
The parotid glands are the largest of
the salivary glands (the glands which make saliva). They are close to the
jawbone, just in front of the ear, one on the right and one on the left. About
7 out of 10 salivary gland tumors start here. Most of these tumors are benign
(not cancer), but the parotid glands still are where most malignant (cancerous)
salivary gland tumors form.
Acinic Cell Carcinoma was initially thought to be a benign disease. Because of its
rarity, initial misunderstanding and unknown character, it has been difficult
to study.
Treatment
Acinic cell cancer grows slowly and it is usually possible to operate to remove it. However,
if the cancer is advanced when it is found, it may not be possible to
completely remove it as there is a risk of damage to vital nerves near the
parotid gland.
Radiotherapy often occurs after surgery. Radiotherapy is given to reduce the
possibility of the cancer coming back in the same area. These cancers do not usually
spread to other parts of the body. However, in some cases, the cancer can
spread to the lymph nodes in the neck.
Risk factors
The cause of most
salivary gland cancers is unknown, but some factors that may increase a person’s
risk of developing salivary gland cancer. Talk with your doctor for more
information about your personal risk of cancer and how you may be able to lower
your risk.
Age
About two out of every three salivary
gland cancers are found in people 55 and older, with an average age of 64.
Radiation exposure
Radiation therapy to the head or neck
for another medical reason may increase the risk of developing salivary gland
cancer.
Radioactive substance exposure
In some reports, exposure to certain
radioactive substances has been linked to an increased risk of salivary gland cancer.
Other reports suggest that there has not been enough evidence to support this.
Talk with your doctor for more information.
Environmental/occupational exposure
Exposure to sawdust and chemicals
used in the leather industry, pesticides, and some industrial solvents may
increase the risk of salivary gland cancer in the nose and sinuses.
Early symptoms
Patients usually visit doctors with the
symptom of incidental infra-auricular mass. Facial palsy or pain usually may
not exist in the first instance. In other studies, the tumor usually appeared
as a painless mass in either the superficial or deep lobe of the parotid gland.
Not everyone with the symptoms above will have cancer but see your general practitioner (GP) if you are concerned.
Diagnosis/diagnosing
Tests and procedures are used to diagnose salivary
gland tumors.
Physical exam
Your doctor will feel your jaw, neck
and throat for lumps or swelling.
Imaging tests
Imaging tests, such as magnetic
resonance imaging (MRI), computerized tomography (CT), positron emission
tomography (PET), ultrasound or X-ray, may help your doctor determine the size
and location of your salivary gland tumor.
Biopsy
During the biopsy, the doctor inserts
a thin needle into the salivary gland to draw out a sample of suspicious cells.
Doctors in a lab analyze the sample to determine what types of cells are
involved and whether the cells are cancerous.
Prognosis (Certain factors
affect the prognosis and treatment options)
Generally Acinic Cell Carcinoma has less
aggressive behavior and is considered a low-grade salivary gland carcinoma with
low rate of recurrence and metastasis. It is usually thought to carry a good
prognosis.
The ten year survival rate is over 65%.
Reference
Some references are to overseas websites. There may be
references to drugs and clinical trials that are not available here in
Australia.