Carcinoma ex pleomorphic adenoma (CXPA) is a rare type of salivary gland cancer. Surgery and radiation therapy are the most common treatment options.
CXPA develops from a noncancerous tumor called pleomorphic adenoma. Pleomorphic adenoma is the most common type of salivary gland tumor. Only a small percentage of these tumors become CXPA.
Pleomorphic adenoma most commonly develops in your parotid glands. Your parotid glands are two large salivary glands in front of and below each of your ears. Less commonly, CXPA develops in other salivary glands, such as those under your tongue or jaw.
In this article, we examine CXPA in more detail, including typical symptoms, treatment options, and outlook.
How common is CXPA?
Pleomorphic adenoma occurs in about
It’s thought that CXPA makes up about 12% of salivary gland cancers and 4% of salivary gland tumors. It’s also been reported to make up about 5% to 25% of parotid cancers.
The risk of cancerous transformation of pleomorphic adenoma to CXPA is about
You might not have noticeable symptoms in the early stages of CXPA. The most common symptom of pleomorphic adenoma is a
About two-thirds of cases of CXPA develop in the parotid glands located in front and below your ears.
You might develop pain or discomfort as the tumor grows larger and begins to press on surrounding structures.
Other general signs of salivary cancer can include:
- swelling around your jaws, ears, or mouth
- tooth pain
- tingling or burning sensation in your lower face
- swollen lymph nodes
- difficulty swallowing
- facial nerve weakness
- fatigue
- lethargy
How aggressive is carcinoma ex pleomorphic adenoma?
CXPA tends to be aggressive and can spread to distant body parts if not treated promptly. It comes in low-grade and high-grade varieties. High-grade CXPA usually spreads quickly to distant tissues such as your lungs or lymph nodes.
In a 2023 review, researchers examined the features of a group of people with CXPA diagnosed at one hospital. They reported the following stage breakdown at the time of diagnosis.
| Stage | Number of people |
|---|---|
| Stage 0 | 6 |
| Stage 1 | 12 |
| Stage 2 | 9 |
| Stage 3 | 6 |
| Stage 4 | 7 |
In the same study, researchers performed a literature review in which they examined the features of 3,262 confirmed cases of CXPA from 62 articles. The researchers reported the following as the most common sites the cancer has spread to:
| Location | Number |
|---|---|
| Lymph nodes | 355 |
| Lung | 73 |
| Brain/CNS | 9 |
| Bone | 9 |
| Liver | 4 |
CXPA is rare and poorly understood, but it develops from a benign tumor called pleomorphic adenoma. Pleomorphic adenoma is thought to make up from
It’s thought that long-standing genetic instabilities can lead to cancerous transformation to CXPA. Most people who develop CXPA are in their 50s or 60s. It seems to be rare in young adults.
In the previously mentioned review of 3,262 people, researchers reported about 50% more cases in males than females.
Your doctor might suspect salivary gland cancer if you have a lump over one of your salivary glands. Initial tests your doctor will likely perform include:
- a physical examination to look for swelling around your salivary glands
- a review of your personal and family medical history
- a review of your symptoms
Additional tests you might receive include:
- imaging such as:
fine-needle aspiration , where a doctor inserts a small needle into the tumor to draw out a small tissue sample
Fine needle aspiration is needed to differentiate CXPA from other types of salivary tumors. The tissue sample is sent to a laboratory so doctors can look at the cell types and certain genetic markers.
The primary treatment for CXPA is surgery followed by radiation therapy if it’s thought there’s a high risk that it might spread to other tissues.
At this time, it’s still unclear whether chemotherapy offers additional benefits, but it may be given to people with advanced cancer to help extend survival or reduce symptoms.
Surgery may involve removing part or all of your parotid gland (parotidectomy) as well as removing surrounding tissue. You may all need reconstructive surgery to preserve the form and function of your face.
The outlook for CXPA depends largely on whether you have a low-grade or high-grade variant. It’s often curable if you have a less aggressive variant and treatment is initiated soon.
Studies have reported 5-year survival rates as low as 25% to 65% for high-grade CXPA and up to 100% for low-grade CXPA.
Salivary gland cancer survival by stage
In general, people with salivary gland cancer have a better chance of survival when it’s caught early. Here’s a look at the
| Stage | 5-year relative survival rate |
|---|---|
| Localized | 94% |
| Regional | 70% |
| Distant | 43% |
| All stages | 76% |
CXPA is a type of salivary gland cancer that develops from a benign tumor called pleomorphic adenoma. It tends to be aggressive and is most often treated with surgery, which is sometimes combined with radiation therapy.
The initial sign of pleomorphic adenoma is usually a lump over one of your parotid glands below and in front of your ears.
It’s important to visit a doctor any time you develop an unexplained lump in your face. Not all lumps are cancerous, but further testing is often needed to differentiate cancerous and noncancerous tumors.