Cutaneous B-cell lymphoma usually appears as a lump or group of lumps on the skin that don't go away. Symptoms may include:

• A single lump or group of lumps on the skin.
• A lump or lumps on the skin that may look pink, purple or red-brown.
• Redness around the skin lumps.
• Skin lumps that grow slowly.

Cutaneous B-cell lymphomas most often grow on the scalp, forehead or back. Some types of this cancer prefer to grow in other places. Primary cutaneous marginal zone B-cell lymphomas tend to grow on the arms or trunk. Primary cutaneous diffuse large B-cell lymphoma, leg type usually grows on one leg.

Intravascular diffuse large B-cell lymphoma causes symptoms that are different from the other types. The symptoms may include:

• Hard skin patches.
• Skin around the patches that looks red or purple.
• Areas of skin that look like spider veins.
• Patches on the trunk or thighs.

When to see a doctor

Make an appointment with a doctor or other healthcare professional if you have ongoing symptoms that worry you.

The cause of cutaneous B-cell lymphoma often isn't known. This cancer causes a growth of cells in the skin. It starts in germ-fighting white blood cells called lymphocytes. Cutaneous B-cell lymphoma affects specific lymphocytes called B lymphocytes.

Cutaneous B-cell lymphoma happens when B lymphocytes develop changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA gives instructions to grow and multiply at a set rate. The instructions tell the cells to die at a set time. In cancer cells, the DNA changes give different instructions. The changes tell the cancer cells to grow and multiply quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells.

In cutaneous B-cell lymphoma, the cancer cells build up in the skin. The cancer cells rarely spread to other areas of the body.

Risk factors for cutaneous B-cell lymphoma include:

• Weakened immune system. If the body's germ-fighting immune system is weakened by medicine or illness, there might be a higher risk of cutaneous B-cell lymphoma. People with weakened immune systems might include those taking medicine to control the immune system, such as after an organ transplant. Certain health conditions also can weaken the immune system, including HIV infection.
• Bacteria transmitted by ticks. Some ticks can transmit bacteria called Borrelia. Borrelia bacteria is linked to Lyme disease. There is some research that also links Borrelia bacteria to cutaneous B-cell lymphoma.

There is no way to prevent cutaneous B-cell lymphoma.

Tests and procedures used to diagnose cutaneous B-cell lymphoma include:

• Physical exam. Your healthcare professional will carefully check your skin. Your health professional looks for other signs that may give clues about your diagnosis.
• Skin biopsy. A biopsy is a procedure to remove a sample of tissue for testing in a lab. Your healthcare professional may remove a small piece of the affected skin. The sample is tested in a lab to look for lymphoma cells.
• Blood tests. A sample of your blood may be analyzed to look for lymphoma cells.
• Bone marrow biopsy. A sample of your bone marrow may be tested to look for lymphoma cells.
• Imaging tests. Imaging tests may help your healthcare professional assess your condition. Examples of imaging tests include computerized tomography scans, also called CT scans, and positron emission tomography scans, also called PET scans.

Cutaneous B-cell lymphoma treatment depends on the specific type of lymphoma that you have.

Treatment options may include:

• Radiation therapy. Radiation therapy treats cancer with powerful energy beams. The energy can come from X-rays, protons or other sources. Radiation therapy can be used alone to treat cutaneous lymphoma. Sometimes it's used after surgery to kill any cancer cells that might be left.
• Surgery to remove the cancer. Your healthcare professional may recommend a procedure to remove the cancer and some of the healthy tissue that surrounds it. This might be an option if you have one or only a few areas of cutaneous lymphoma. Surgery might be the only treatment needed. Sometimes other treatments are needed after surgery.
• Injecting medicine into the cancer. Sometimes medicine can be injected into the cancer. One example is steroid medicines. This treatment is sometimes used for cutaneous lymphoma that grows very slowly.
• Chemotherapy. Chemotherapy treats cancer with strong medicines. Chemotherapy medicines can be applied to the skin to control cutaneous lymphoma. Chemotherapy also can be given through a vein. This might be used if the cancer is growing quickly or is advanced.
• Targeted therapy. Targeted therapy medicines attack specific chemicals present in cancer cells. By blocking these chemicals, targeted therapy treatments cause cancer cells to die. Targeted therapy medicines can be injected into the cancer to treat cutaneous lymphoma. Or the medicines can be given through a vein.

Make an appointment with a doctor or other healthcare professionals if you have any symptoms that worry you. If your healthcare professional feels that you may have cutaneous B-cell lymphoma, that person may refer you to a specialist. Often this is a doctor who specializes in treating skin conditions, called a dermatologist.

Appointments can be short and being prepared can help. Here's some information that may help you get ready.

What you can do

When you make the appointment, ask if there's anything you need to do in advance, such as fasting before having a specific test. Make a list of:

• Your symptoms, including any that seem unrelated to the reason for your appointment.
• Key personal information, including major stresses, recent life changes and family medical history.
• All medications, vitamins or other supplements you take, including the doses.
• Questions to ask your doctor.

Take a family member or friend along, if possible, to help you remember the information you're given.

For cutaneous B-cell lymphoma, some basic questions to ask your doctor include:

• Do I have cancer?
• If the lumps aren't cancerous, do I still need to have them removed?
• Do I need more tests?
• What are my treatment options?
• What are the potential risks for these treatment options?
• Do any of the treatments cure my cancer?
• Can I have a copy of my pathology report?
• How much time can I take to consider my treatment options?
• Are there brochures or other printed materials that I can take with me? What websites do you recommend?
• What would happen if I choose not to have treatment?

Don't hesitate to ask other questions.

What to expect from your doctor

Your doctor is likely to ask you several questions, such as:

• When did your symptoms begin?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?