Glomus Tumor - Causes, Symptoms, and Management

What Is a Glomus Tumor?

Glomus tumors are rare, slow-growing, usually benign neuroendocrine tumors that are usually created along the arteries and nerves that are primarily present in the head and neck region. They are also known as paragangliomas. These tumors are usually formed in the carotid arteries (major artery in the neck), the middle ear, or the jugular bulb present within the temporal bone. Glomus tumors are most often treatable; however, they can significantly damage the surrounding tissues as they grow in size. Glomus tumor was the former (and incorrectly) used name for a tumor that is now known as paraganglioma.

What Is the Cause of Glomus Tumor?

A glomus tumor or a paraganglioma is an uncontrolled growth of abnormal tumor cells that derive their origin from chromaffin cells (specific nerve cells that are present throughout the body). These chromaffin cells perform some crucial functions in the body, including blood pressure regulation. The exact cause for this abnormal tumor cell growth is unknown. It usually occurs sporadically. Most people developing this tumor have a genetic condition that is passed down through their family, including the following:

• Multiple endocrine neoplasia type 2 syndrome- type 2A and 2B.

• Neurofibromatosis type 1.

• Hereditary paraganglioma syndrome.

• Paraganglioma and gastrointestinal stromal tumor.

What Is the Epidemiology of Glomus Tumors?

The tumor can occur at any age but is usually present between the third and fifth decades of life. A few cases occur in children also. Glomus tumor is a rare tumor. It is estimated that only two out of one million people are diagnosed with tumors.

What Are the Symptoms of Glomus Tumor?

The symptoms of a glomus tumor arise when too much adrenaline or noradrenaline is released from the tumor into the bloodstream. However, some of the glomus tumors are asymptomatic. Some of the common symptoms of the disease include episodes of

• Hypertension (high blood pressure).

• Severe headache.

• Sweating too much without any known cause.

• Arrhythmias (irregular, fast heartbeats).

• Dizziness.

• Mental imbalance.

• Pale skin color.

• Nausea and vomiting.

• Constipation or diarrhea.

• High blood glucose levels.

• Sudden weight loss.

• Loss of appetite.

• Lethargy and weakness.

• Anxiety.

• Hearing loss.

• Tinnitus.

• Ear pain.

• Difficulty swallowing food.

How Is Glomus Tumor Diagnosed?

Diagnostic tests that can be used to detect glomus tumors include the following:

• Hematological and Urine Tests - The doctor may suggest certain urine and blood tests to evaluate the hormone levels in the body. These tests may detect extra hormones produced by paraganglioma cells or a tumor marker called chromogranin A.

• Imaging Tests - These diagnostic imaging tests scan images of the glomus tumor that will help the doctor to evaluate the tumor size and tumor extent. This, in turn, determines the treatment options available. Tests include magnetic resonance imaging, computed tomography, and a positron emission tomography scan.

• Genetic Testing - Glomus tumors are sometimes caused by genetic mutations that are passed down from family to child. Genetic testing is therefore recommended to take necessary precautions.

What Is the Treatment of Glomus Tumor?

The management of the glomus tumor depends on the location of the tumor, the metastatic ability of the tumor, and excessive hormone production. Surgery is often required to treat these tumors. If the glomus tumor cells synthesize excessive hormones, it is important to block the hormone production with medications before commencing the treatment. If the glomus tumor spreads to other body parts, additional treatment options should be considered.

These treatment strategies include the following:

• Control of Excessive Hormonal Production - If the tumor is producing excess hormones, treatment is required to minimize hormone levels and control symptoms. Drugs that are used to reduce hormone levels include alpha and beta blockers and calcium channel blockers. Other therapeutic measures include eating a high-sodium diet and drinking lots of fluids.

• Surgery - Even if the tumor cannot be excised completely, the doctor recommends performing an operation to eliminate the tumor as much as possible.

• Radiation Therapy - This therapy uses X-rays to combat tumor growth. Radiation therapy is usually considered when the glomus tumor cannot be surgically removed completely. It is also preferred to alleviate the pain that is caused by the metastasizing tumor to different parts of the body. Stereotactic body radiotherapy is a special type of radiotherapy that involves multiple radiation beams that are aimed at the tumor. This is a low-risk technique since there is minimal damage to the surrounding healthy tissues.

• Thermal Ablation Therapy - Thermal ablation therapy makes use of either heat energy or cold gas to kill tumor cells and prevent further growth of the tumor.

• Chemotherapy - This therapy uses pharmacological drugs to destroy tumor cells. The doctor may suggest chemotherapy to shrink the tumor size. If the glomus tumor secretes excess hormones, medications will be provided to minimize the hormone levels before starting chemotherapy.

• Targeted Drug Therapy - It focuses on specific defects present within tumor cells. Targeted drug therapy can reduce the growth of tumor cells or kill them by blocking their growth.

• Watchful Wait - In certain cases, when the glomus tumor is slow-growing and not showing any signs or symptoms, the doctor may delay the treatment to monitor the condition regularly during follow-up appointments.

What Is the Prognosis of Glomus Tumor?

If the tumor is benign and has not spread to other parts of the body, the prognosis is good. But if the tumor, whether benign or malignant, is left untreated, it can pose serious debilitating, life-threatening conditions such as uncontrolled bleeding in the brain, inflammation of the heart muscle, heart attack, brain stroke, or even coma.

Conclusion

Glomus tumor is a rare neuroendocrine tumor. It usually comprises less than 3 percent of all the soft tissue mesenchymal tumor masses. If a person is diagnosed with this tumor, the patient should immediately consult a healthcare professional. Genetic testing should be done if the disease is found to be due to hereditary causes. Hormonal control of the patient is very important before starting the surgery. Complete surgical removal of the capsule of the tumor mass is recommended to prevent the recurrence rate of the glomus tumor and alleviate pain.