Adenoid Cystic Carcinoma

Adenoid cystic carcinoma (ACC) is a rare type of cancer that can develop in many parts of the body, most often in the salivary glands in the head and neck. While it usually grows slowly, ACC can be aggressive, often spreading along nerves and sometimes to distant organs like the lungs. Early detection and treatment are important for managing this condition.

What is Adenoid Cystic Carcinoma?

Adenoid cystic carcinoma (ACC) is a rare cancer that can develop in various parts of the body, most commonly in the salivary glands located in your head and neck. Although it often grows slowly, ACC is considered an aggressive cancer because it tends to spread along nerves and can recur even years after treatment.

Adenoid cystic carcinoma (ACC) is a type of cancer that is not very common. It can start in many different places in your body. However, it most often begins in the salivary glands. These glands make saliva (spit) and are found in your mouth and neck, such as the parotid, submandibular, and sublingual glands. ACC can also form in other areas of the head and neck, including the tear glands, sinuses, tongue, and throat. Less commonly, it can appear in organs like the skin, breast, lungs, or brain. Even though ACC often grows slowly, it is considered an aggressive cancer. This means it has a tendency to spread. It often spreads along nerves, a process called perineural invasion. ACC can also spread to distant parts of the body, known as metastasis, most commonly to the lungs. It has a high chance of coming back (recurrence) even after successful treatment, sometimes many years later.

Symptoms

Symptoms of adenoid cystic carcinoma (ACC) vary depending on where the cancer is located in your body. Common signs can include a new lump or swelling, pain, numbness, or weakness in the affected area. You might also experience difficulty swallowing, changes in your voice, or shortness of breath if the tumor is in your throat or lungs.

The signs and symptoms of adenoid cystic carcinoma (ACC) depend on where the cancer is growing. If the cancer is in a salivary gland, you might notice a lump in your mouth or neck. This lump may or may not be painful. You might also feel pain, numbness, or weakness in your face. If ACC develops in your trachea (windpipe) or lungs, symptoms can include a persistent cough, shortness of breath, or hoarseness in your voice. A lump in the breast could be a symptom if the cancer starts there. Difficulty swallowing or speaking can also occur. Because ACC can spread along nerves, you might experience nerve-related symptoms like tingling, numbness, or weakness in the area affected by the tumor.

Causes & risk factors

The exact causes of adenoid cystic carcinoma (ACC) are not clearly understood, and researchers are still studying why it develops. Unlike some other cancers, there are no known specific risk factors that reliably increase your chance of getting ACC. It can affect anyone, regardless of their lifestyle or environmental exposures.

Medical experts do not currently know what causes adenoid cystic carcinoma (ACC). It is not linked to specific lifestyle choices, environmental exposures, or genetic factors in the way some other cancers are. Researchers continue to study ACC to better understand its origins. At this time, there are no clear risk factors that have been identified for developing ACC. This means that people who develop ACC often do not have any specific pre-existing conditions or exposures that would explain why they got the cancer.

How it's diagnosed

Diagnosing adenoid cystic carcinoma (ACC) typically involves a combination of a physical exam, imaging tests, and a biopsy. Your doctor will examine any lumps or affected areas and use imaging like MRI or CT scans to see the tumor's size and location. A biopsy, which involves taking a tissue sample, is essential to confirm the diagnosis.

If your doctor suspects adenoid cystic carcinoma (ACC), they will start with a physical exam. During this exam, they will carefully check for any lumps, swelling, or other unusual signs in the affected area. They will also assess your nerve function if the tumor is in the head or neck. Imaging tests are crucial for seeing the tumor inside your body. These tests can include a computed tomography (CT) scan, magnetic resonance imaging (MRI), or sometimes a positron emission tomography (PET) scan. These scans help doctors determine the exact size and location of the tumor and whether it has spread to other areas. The most important step for a definitive diagnosis of ACC is a biopsy. During a biopsy, a small sample of tissue is removed from the suspicious area. This tissue is then examined under a microscope by a pathologist, a doctor who specializes in diagnosing diseases by looking at cells and tissues. There are different types of biopsies, such as a fine-needle aspiration (FNA), where a thin needle is used to collect cells, or an incisional biopsy, where a small piece of tissue is surgically removed. The pathologist's report confirms if the cells are cancerous and identifies them as ACC.

Treatment options

Treatment for adenoid cystic carcinoma (ACC) usually involves surgery to remove the tumor, often followed by radiation therapy. Surgery is the primary treatment, aiming to remove as much of the cancer as possible. Radiation therapy helps kill any remaining cancer cells or manage tumors that cannot be surgically removed. Chemotherapy is less commonly used and typically reserved for advanced cases.

The main treatment for adenoid cystic carcinoma (ACC) is surgery. The goal of surgery is to remove the tumor completely, along with a margin of healthy tissue around it. Because ACC often spreads along nerves, surgeons must be very careful to remove all affected tissue to reduce the chance of the cancer coming back. After surgery, radiation therapy is often recommended. This treatment uses high-energy beams to kill any cancer cells that might have been left behind after surgery. Radiation therapy can also be used as the main treatment if the tumor cannot be completely removed with surgery, or if surgery is not an option for other health reasons. Chemotherapy, which uses drugs to kill cancer cells, is generally less effective for ACC compared to other cancers. It is typically considered for advanced cases where the cancer has spread to distant parts of the body (metastasis) or when other treatments have not been successful. Targeted drug therapy, which focuses on specific weaknesses in cancer cells, is an area of ongoing research and may be used in some advanced cases, but its role is still being studied. Your medical team will discuss the best treatment plan for your specific situation.

Recovery & outlook

The recovery and outlook for adenoid cystic carcinoma (ACC) can vary greatly among individuals. While ACC often grows slowly, it has a high chance of recurring, sometimes many years after initial treatment, and can spread to distant sites, most often the lungs. Long-term follow-up care is essential to monitor for any recurrence or spread of the cancer.

Adenoid cystic carcinoma (ACC) is known for its slow growth but also its aggressive nature. This means that while it might not grow quickly, it has a high tendency to come back (recur) even after successful treatment. Recurrence can happen locally, meaning in the same area, or in distant parts of the body, most commonly the lungs. This can occur many years after the initial diagnosis and treatment. Because of the risk of recurrence and metastasis (spread), long-term follow-up care is very important for people with ACC. This typically involves regular check-ups, imaging scans, and other tests to monitor for any signs of the cancer returning or spreading. The overall outlook for ACC depends on several factors, including the tumor's location, its size, whether it has spread to nerves or distant organs, and how completely it was removed during surgery. While ACC can be challenging to manage due to its tendency to recur and spread, ongoing research is exploring new treatment approaches to improve outcomes. Your medical team will provide personalized information about your specific prognosis.

When to see a doctor

You should see a doctor if you notice any new or unusual lumps or swellings, especially in your head or neck area. Other concerning symptoms include persistent pain, numbness, or weakness in your face or other body parts, difficulty swallowing, changes in your voice, or unexplained shortness of breath. Early evaluation of these symptoms is important.

It is important to pay attention to your body and seek medical advice if you experience any concerning symptoms. You should make an appointment with your doctor if you find any new lump or swelling, particularly in your mouth, neck, or face. Even if a lump is painless, it should be checked by a healthcare professional. Other symptoms that warrant a doctor's visit include persistent pain in your head or neck, unexplained numbness or weakness in your face or other areas, or any new difficulty swallowing or speaking. If you develop a persistent cough, hoarseness that doesn't go away, or unexplained shortness of breath, these also need medical evaluation. While these symptoms can be caused by many less serious conditions, it is always best to have them checked by a doctor to get an accurate diagnosis.

Frequently asked questions

Is adenoid cystic carcinoma always cancerous?

Yes, adenoid cystic carcinoma (ACC) is by definition a type of cancer. It is a malignant tumor, meaning it has the potential to grow, invade surrounding tissues, and spread to other parts of the body.

How fast does adenoid cystic carcinoma grow?

Adenoid cystic carcinoma (ACC) is generally considered a slow-growing cancer. However, despite its slow growth, it is aggressive and can spread along nerves and to distant organs, often recurring many years after initial treatment.

Can adenoid cystic carcinoma be cured?

While complete removal with surgery and radiation therapy can be very effective, adenoid cystic carcinoma (ACC) has a high rate of recurrence, sometimes years later. Long-term monitoring is crucial, and the term "cure" can be complex due to its aggressive nature and potential for late recurrence.

Does adenoid cystic carcinoma spread to lymph nodes?

Adenoid cystic carcinoma (ACC) typically does not spread to lymph nodes as often as some other head and neck cancers. It is more characteristic for ACC to spread along nerves (perineural invasion) and to distant organs, most commonly the lungs.

What is the difference between adenoma and adenoid cystic carcinoma?

An adenoma is a benign (non-cancerous) tumor that forms in glandular tissue. Adenoid cystic carcinoma (ACC), on the other hand, is a malignant (cancerous) tumor that also originates in glandular tissue but has the ability to invade, spread, and recur.

What kind of doctor treats adenoid cystic carcinoma?

Treatment for adenoid cystic carcinoma (ACC) usually involves a team of specialists. This team may include a head and neck surgeon, a radiation oncologist (a doctor specializing in radiation therapy), and sometimes a medical oncologist (a doctor specializing in chemotherapy and systemic treatments).

Sources

• MedlinePlus — Adenoid Cystic Carcinoma
• Mayo Clinic — Adenoid Cystic Carcinoma
• Cochrane Library — Adenoid Cystic Carcinoma