Diagnosing Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphoma is a rare form of cancer that develops when T lymphocytes, which are white blood cells that fight infection, grow and multiply uncontrollably in the skin. This chronic condition requires ongoing care and management.

T cells are made in the bone marrow, the soft, spongy tissue found in the center of bones throughout the body, and then mature in the thymus, a small gland in the chest that is part of the body’s lymphatic system. In addition to the bone marrow and thymus, the lymphatic system consists of a series of vessels that drain excess fluid from tissues; lymph nodes, which are small glands located throughout the body that filter this fluid and trap foreign substances, such as viruses and bacteria; and other small organs, such as the spleen, which plays a role in producing white blood cells. 

Healthy T cells circulate throughout the lymphatic system, reaching the body’s many organs, including the skin. In people with cutaneous T-cell lymphoma, cancerous T cells begin to grow in the skin, causing a rash and possibly tumors on the skin. Sometimes, these abnormal T cells can move from the skin into nearby lymph vessels and then collect in lymph nodes, forming tumors inside the body. 

Doctors at NYU Langone specialize in diagnosing and distinguishing cutaneous T-cell lymphoma from other forms of lymphoma and from skin diseases, such as psoriasis or eczema, ensuring that you receive the most appropriate care as soon as possible. 

Types of Cutaneous T-cell Lymphoma

Several types of cutaneous T-cell lymphoma exist. Mycosis fungoides and Sézary syndrome are the two most common of these.

Mycosis Fungoides

Mycosis fungoides often begins as a flat skin rash, which can develop into raised and scaly pinkish areas called plaques. Tumors of more than a centimeter thick can also form on the skin. In addition to a persistent rash, symptoms of mycosis fungoides include severe itching, swollen lymph nodes, frequent fevers, chills, and sweating. This condition, for which there are no associated risk factors, is often slow to progress. 

Sézary Syndrome

Sézary syndrome is not well understood. It may be a more advanced or aggressive form of mycosis fungoides, or it may be a different illness altogether.

People with Sézary syndrome develop erythroderma, in which the skin on most of the body becomes red and itchy. The skin may also peel, and the condition can be painful. With Sézary syndrome you may have a high number of white blood cells, as cancerous T cells begin to grow and multiply in the bloodstream. The condition has no known risk factors. 

NYU Langone physicians are conducting research to improve their understanding of Sézary syndrome, which may one day lead to better and more personalized therapy.

Diagnostic Tests

In addition to a physical examination of the skin and lymph nodes, your doctor may conduct several tests to diagnose cutaneous T-cell lymphoma and to determine whether and how far the disease has spread. Based on your test results, our doctors develop a treatment program using several therapies that target the skin and whole body.

Blood Tests

Blood tests allow doctors to measure the level of white blood cells in the body, which can determine whether you have Sézary syndrome. People with mycosis fungoides usually do not have cancerous T-cell lymphocytes circulating in the blood. When they do, it is a sign that the condition may be more advanced. 

Doctors can also measure red blood cell and platelet levels, which may be low if either type of cutaneous T-cell lymphoma has spread to the bone marrow, where healthy blood cells are made.

Skin Biopsy

An NYU Langone dermatopathologist—a doctor who specializes in diagnosing diseases of the skin—conducts a skin biopsy, which involves the removal of tissue for examination under a microscope. While your skin is numbed with a local anesthetic, the doctor shaves off a thin slice of skin where the rash or tumor has appeared. Several skin samples from different areas may need to be taken. 

A doctor may also conduct tests on the skin sample to look at how the body’s immune system is working and to identify gene mutations that may help in diagnosing mycosis fungoides or Sézary syndrome.  

PET Scan

If cutaneous T-cell lymphoma is found with a skin biopsy, doctors at NYU Langone may use a full-body PET scan to see whether cancer has spread beyond the skin to other soft tissues of the body, such as the lymph nodes, causing them to enlarge and forming tumors there. A PET scan measures activity in tumor cells within the body and can show whether they are cancerous. 

Before the scan, a small amount of radioactive glucose is injected into a vein through intravenous (IV) infusion. This radioactive glucose collects in any cancerous cells, which are detected using a special camera. A computer creates three-dimensional images of tissue activity. 

Lymph Node Biopsy

Our doctors may perform a lymph node biopsy to help confirm a diagnosis if a skin biopsy does not provide enough information. This type of biopsy can also be used after a diagnosis to help your doctor to determine if mycosis fungoides or Sézary syndrome has spread to the lymph nodes. Your doctor may suspect that a lymph node contains cancer if it feels swollen during a physical examination or if a PET scan reveals an enlarged lymph node and shows cancer activity there. 

Surgical Biopsy

Often, our doctors choose to remove one lymph node during a surgical procedure. This allows them to obtain enough tissue to study under a microscope. Your physicians may also test tissue to find out how the body’s immune system is responding to the cancer and to look for genetic abnormalities that can aid the doctor in making a diagnosis. 

A surgical biopsy takes place in the hospital. Depending on how deep the lymph node is within the body, the procedure may require general anesthesia. 

Needle Biopsy

If your doctors believe surgery poses a risk to your health, they may try to obtain a smaller tissue sample using a needle, which is less invasive. 

Fine needle aspiration, a technique in which a small needle is used to withdraw fluid and cells from a lymph node mass, is one possibility. An alternative is a core needle biopsy, in which a bigger needle is used to remove more tissue. If the lymph node is deep within the body, your doctors may use imaging technology, such as a CT scan or an ultrasound, to assist in locating it during the biopsy. 

Bone Marrow Aspiration and Biopsy

After diagnosis, our doctors may use bone marrow aspiration and biopsy to see if cutaneous T-cell lymphoma has spread to bone marrow. During the aspiration, your doctor uses a needle to withdraw liquid from the bone marrow in the back of the pelvis. For a bone marrow biopsy, he or she removes a piece of bone and solid marrow from this same area. These samples are then evaluated under a microscope for signs of cutaneous T-cell lymphoma. Your doctor may use a local anesthetic to ensure you are as comfortable as possible during the procedure.

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