Understanding Merkel Cell Carcinoma: Symptoms, Diagnosis, and Treatment

Merkel Cell Carcinoma (MCC) is a rare but aggressive skin cancer that begins in the Merkel cells, a type of cell located in the skin’s hair follicles and responsible for the sense of touch. Although it is rare, MCC has a high potential for metastasis and can quickly spread to other parts of the body, making it a serious and potentially life-threatening disease.

What is Merkel Cell Carcinoma?

Merkel Cell Carcinoma (MCC) is a rare type of skin cancer that develops in the Merkel cells of the skin. These cells are responsible for the sense of touch and are found in the outermost layer of the skin, called the epidermis. MCC accounts for only about 0.2% of all skin cancers, but its incidence has been increasing steadily in recent years.

Although MCC is a rare form of skin cancer, it is a very aggressive and fast-growing cancer that can spread quickly to other parts of the body. It primarily affects older adults and people with weakened immune systems. MCC usually appears on sun-exposed areas of the skin, such as the head, neck, and arms, as a painless, firm, red, or purple bump that grows rapidly over weeks or months.

The Role of Merkel Cells in the Skin

Merkel cells are specialized cells in the skin that help with the sense of touch. They are located at the base of the epidermis and are connected to nerve fibers. When you touch something, the Merkel cells detect the pressure and send signals to the brain, allowing you to feel the sensation. However, when Merkel cells become cancerous, they can start to grow and divide uncontrollably, leading to MCC.

Scientists are still trying to understand the exact role of Merkel cells in the development of MCC. However, it is believed that exposure to ultraviolet (UV) radiation from the sun or tanning beds can damage the DNA in the Merkel cells, which can then lead to the development of cancer.

Causes and Risk Factors

The exact cause of MCC is unknown, but it is thought to be linked to exposure to ultraviolet (UV) radiation from the sun or tanning beds. Other risk factors include having a weakened immune system due to conditions like HIV or organ transplants, having a history of other skin cancers, and being over the age of 50.

People who work outdoors or have a history of excessive sun exposure are also at an increased risk of developing MCC. In addition, people who have a family history of skin cancer or who have a genetic condition that increases their risk of developing skin cancer may also be at a higher risk of developing MCC.

If you have any concerns about your risk of developing MCC, it is important to talk to your doctor. They can help you understand your risk factors and recommend steps you can take to reduce your risk of developing this rare but aggressive form of skin cancer.

Symptoms of Merkel Cell Carcinoma

Common Signs and Indicators

The most common symptom of Merkel Cell Carcinoma (MCC) is a painless, firm, red, or purple bump on the skin that grows rapidly over weeks or months. The bump may also be shiny, smooth, and dome-shaped, with visible blood vessels on the surface. It usually appears on sun-exposed areas of the skin, such as the face, neck, arms, and legs.

Although MCC is a rare form of skin cancer, it is highly aggressive and can spread quickly to other parts of the body. Therefore, it is important to seek medical attention as soon as you notice any unusual growths or changes on your skin.

How Symptoms Progress Over Time

If left untreated, MCC can quickly spread to other parts of the body, including the lymph nodes, liver, lungs, and bones. This can cause a variety of symptoms, depending on the location and extent of the cancer.

If the cancer spreads to the lymph nodes, you may notice swelling or lumps in your neck, armpit, or groin. The affected area may also feel tender or painful to the touch.

If the cancer spreads to the liver, you may experience abdominal pain, nausea, vomiting, or jaundice (yellowing of the skin and eyes).

If the cancer spreads to the lungs, you may have difficulty breathing, coughing, or chest pain.

If the cancer spreads to the bones, you may experience bone pain, fractures, or weakness.

Other symptoms of advanced MCC may include fatigue, weight loss, and loss of appetite.

It is important to note that not everyone with MCC will experience these symptoms, and some people may not have any symptoms at all. Therefore, it is crucial to have regular skin exams and to report any changes in your skin to your healthcare provider.

Diagnosing Merkel Cell Carcinoma

Physical Examination and Medical History

If you have a suspicious bump on your skin, your doctor will perform a physical examination and take a detailed medical history to determine if further testing is necessary. They will also ask about any symptoms you are experiencing and any risk factors you may have.

During the physical examination, your doctor will carefully examine the suspicious bump and surrounding areas. They will look for signs of skin cancer, such as changes in color, texture, and size. Your doctor may also check your lymph nodes for swelling or tenderness, which can be a sign that the cancer has spread.

When taking your medical history, your doctor will ask about your personal and family history of cancer, any previous skin biopsies or skin cancer diagnoses, and any medications you are currently taking. They will also ask about your sun exposure history and any other risk factors for skin cancer.

Imaging Tests

Your doctor may order imaging tests such as X-rays, CT scans, or MRI scans to look for signs of cancer in your body. These tests can help determine the size and location of the tumor and whether it has spread to other parts of the body.

X-rays use a small amount of radiation to create images of the inside of your body. CT scans use X-rays and a computer to create detailed images of your body’s organs and tissues. MRI scans use a magnetic field and radio waves to create images of your body’s internal structures.

If your doctor suspects that the cancer has spread to your lymph nodes, they may order a lymph node biopsy. This procedure involves removing a small sample of tissue from the lymph node and examining it under a microscope.

Biopsy Procedures

The only way to confirm a diagnosis of MCC is through a biopsy, a procedure in which a small sample of tissue is removed from the suspicious bump and examined under a microscope. Depending on the location and size of the bump, your doctor may perform a punch biopsy, an excisional biopsy, or a needle biopsy.

A punch biopsy involves using a tool to remove a small circular piece of skin from the bump. An excisional biopsy involves removing the entire bump and a small amount of surrounding tissue. A needle biopsy involves inserting a thin needle into the bump to remove a small sample of tissue.

After the biopsy, the tissue sample will be sent to a laboratory for examination by a pathologist. The pathologist will look for the presence of Merkel cell carcinoma cells and will determine the stage of the cancer.

Staging Merkel Cell Carcinoma

The TNM Staging System

Once a diagnosis of MCC has been confirmed, your doctor will use the TNM staging system to determine the extent of the cancer and develop a treatment plan. The TNM system takes into account the size and location of the tumor (T), whether it has spread to nearby lymph nodes (N), and whether it has metastasized to other parts of the body (M).

Determining the Stage and Prognosis

Based on the TNM staging system, your doctor will stage your cancer as Stage I, II, III, or IV. The stage of your cancer will determine the best course of treatment and your prognosis, or expected outcome. Generally, the earlier the stage of MCC, the better the prognosis. However, even in advanced cases, treatments are available that can help control the cancer and improve quality of life.

Treatment Options for Merkel Cell Carcinoma

Surgery

Surgery is the primary treatment for MCC and involves removing the tumor and nearby lymph nodes, if necessary, to prevent the cancer from spreading. Depending on the size and location of the tumor, your doctor may perform a wide local excision, a lymph node dissection, or a sentinel lymph node biopsy.

Radiation Therapy

Radiation therapy uses high-energy beams of radiation to kill cancer cells and shrink tumors. It may be used alone or in combination with surgery or chemotherapy to treat MCC. Depending on the stage of your cancer, your doctor may recommend external radiation therapy or internal radiation therapy.

Chemotherapy

Chemotherapy uses drugs to kill cancer cells and is generally reserved for cases of advanced MCC that have spread to other parts of the body. Chemotherapy can be administered orally or through an IV, and it may have side effects such as nausea, vomiting, hair loss, and fatigue.

Immunotherapy

Immunotherapy uses medications to help the immune system fight cancer cells. It has shown promising results in the treatment of MCC, particularly in cases where other treatments have been unsuccessful. Immunotherapy may have side effects such as fever, chills, and rash.

Overall, treatment for MCC depends on the stage of the cancer, the location and size of the tumor, and a patient’s overall health. If you have any concerns about a suspicious bump on your skin, talk to your doctor right away to discuss your treatment options and develop a plan that works for you.