Lymphoma of the Skin

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Early Detection, Diagnosis, and Staging TOPICS

How is lymphoma of the skin diagnosed?

Because this type of lymphoma affects the skin, it is often noticed fairly quickly. But the actual diagnosis of skin lymphoma might be delayed because the symptoms often resemble other, more common skin problems. The diagnosis of skin lymphoma can only be confirmed with tests such as biopsies (described below).

Medical history and physical exam

Usually your doctor first takes your medical history. The doctor probably will ask when the changes in your skin first appeared, if they have changed in size or appearance, and if they are itchy or painful. You may be asked if you have any other symptoms, like fever or weight loss. Because skin lymphomas can be hard to tell apart from allergies and other causes of rashes, you might also be asked if you have recently been exposed to something that could be causing your skin problems, such as if you are taking a new medicine or are using a new laundry detergent or any new creams or lotions.


The doctor might also feel the lymph nodes (small, bean-sized collections of immune cells) under the skin in the neck, underarm, or groin, as lymphomas can sometimes cause lymph nodes to become enlarged.

If you are being seen by your primary doctor and skin lymphoma or another type of skin cancer is suspected, you may be referred to a dermatologist (a doctor who treats skin diseases), who will look at the skin more closely.



Skin biopsies

There are several types of skin biopsies, and the doctor’s choice is based on each person’s situation. Usually a skin biopsy is done by a dermatologist.






Lymph node biopsies


Excisional or incisional lymph node biopsy: This is the most common type of lymph node biopsy. In this procedure, a surgeon cuts through the skin to remove either the entire lymph node (excisional biopsy) or a small part of a large tumor (incisional biopsy). If the node is just under the skin, this is often a simple operation that can be done with local anesthesia. But if the node is inside the chest or abdomen, the patient will be asleep or deeply sedated during the biopsy.

Removing a lymph node almost always provides enough tissue to diagnose the exact type of lymphoma. This type of biopsy is preferred by most doctors, if it can be done without too much discomfort to the patient.

Fine needle aspiration (FNA) biopsy: In an FNA biopsy, the doctor uses a very thin, hollow needle attached to a syringe to withdraw (aspirate) a small amount of tissue from a tumor. If an enlarged node is just under the skin, the doctor can aim the needle while feeling it. If the enlarged node is deep inside the body, the doctor can guide the needle while viewing it with ultrasound or a CT scan (see “Imaging tests” below).

An FNA does not require surgery, but in some cases it doesn’t remove enough tissue to make a definite diagnosis of lymphoma. But advances in lab tests (discussed later in this section) and the growing experience of many doctors with FNA have improved the accuracy of this procedure. Some doctors will use FNA in patients already diagnosed with lymphoma of the skin to confirm that an enlarged lymph node also contains lymphoma.

Other types of biopsies

These procedures may sometimes be done to confirm a diagnosis of lymphoma, but they are more often done to help stage (determine the extent of) a lymphoma that has already been diagnosed. Not everyone with lymphoma of the skin needs these tests.

Bone marrow aspiration and biopsy: These procedures are sometimes done after lymphoma has been diagnosed to help figure out if it has reached the bone marrow. The two tests are often done at the same time. The samples are usually taken from the back of the pelvic (hip) bone, but in some cases they may be taken from other bones.





Lab tests of biopsy or blood samples



In this test, a part of the biopsy sample is treated with special antibodies (man-made versions of immune system proteins) that attach to cells only if specific molecules are on their surface or inside the cells. These antibodies cause color changes, which can be seen under a microscope. This test can be used to help diagnose lymphoma and tell what type it is.

Flow cytometry

Like immunohistochemistry, this test looks for certain substances on the surface of cells that help identify what types of cells they are. But this test can look at many more cells than immunohistochemistry.


This is the most commonly used test for immunophenotyping – classifying lymphoma cells based on the substances (antigens) on their surfaces. Different types of lymphocytes have different antigens on their surface. These antigens also change as each cell matures.

Flow cytometry can help tell whether a biopsy sample contains lymphoma, some other cancer, or a non-cancerous disease. It has also become very useful in helping doctors determine the exact type of lymphoma so that they can select the best treatment.


Doctors use this technique to evaluate the chromosomes (long strands of DNA) in lymphoma cells. The cells are looked at under a microscope to see if the chromosomes have any changes such as translocations (where part of one chromosome has broken off and is now attached to another chromosome), as happens in certain types of lymphoma. Some lymphoma cells may have too many chromosomes, too few chromosomes, or other chromosome abnormalities. These changes can help identify the type of lymphoma.

Cytogenetic testing usually takes about 2 to 3 weeks because the lymphoma cells must grow in lab dishes for a couple of weeks before their chromosomes can be viewed under the microscope.

Molecular genetic tests

These tests look more closely at lymphoma cell DNA. They can detect most changes that are visible under a microscope in cytogenetic tests, as well as others that can’t be seen. These changes can help doctors decide whether a rash or lesion is due to a benign condition or a skin lymphoma. These tests can also tell the difference between B-cell and T-cell lymphomas.


FISH can be used to look for specific gene or chromosome changes. It can be used on regular blood or bone marrow samples. It is very accurate and can usually provide results within a couple of days, which is why this test is now used in many medical centers.

Polymerase chain reaction (PCR): PCR is a very sensitive DNA test that can also find some gene and chromosome changes too small to be seen under a microscope, even if very few lymphoma cells are present in a sample.

Blood tests




Blood chemistry tests: These tests look at how well the kidneys and liver are working.


Imaging tests


  • To help find suspicious areas that might be cancer
  • To learn how far the lymphoma has spread
  • To find out if treatment is working

Imaging tests aren’t always needed for patients with skin lymphomas who have only a few skin lesions, but they are often done in patients with a lot of skin involvement or if lymphoma cells are found in the lymph nodes or blood.

If you’d like to learn more about any of the imaging tests discussed here, see our document Imaging (Radiology) Tests.

Chest x-ray


Computed tomography (CT) scan


Before the test, you may be asked to drink a liquid called oral contrast. This helps outline certain organs. You may also get an IV line through which a different kind of contrast dye (IV contrast) is injected. The injection can cause some flushing (a warm feeling, especially in the face). Some people are allergic to the dye and get hives or, rarely, have more serious reactions like trouble breathing and low blood pressure. Be sure to tell the doctor if you have any allergies (especially iodine or shellfish) or have ever had a reaction to any contrast material used for x-rays.

A CT scanner has been described as a large donut, with a narrow table that slides in and out of the middle opening. You need to lie still on the table while the scan is being done. CT scans take longer than regular x-rays, and some people might feel a bit confined by the ring while the pictures are being taken.

CT-guided needle biopsy: CT scans can also be used to guide a biopsy needle into a suspicious area. For this procedure, a person lies on the CT scanning table while the doctor advances a biopsy needle through the skin and toward the area. CT scans are repeated until the needle is in the right place. A biopsy sample is then removed and sent to the lab to be looked at under a microscope.

Magnetic resonance imaging (MRI) scan


A contrast material called gadolinium is often injected into a vein before the scan to better see details. This contrast material usually does not cause allergic reactions.

MRI scans take longer than CT scans – often up to an hour. You may have to lie inside a narrow tube, which is confining and can be distressing to some people. Newer, more open MRI machines might be another option. The MRI machine makes loud buzzing and clicking noises that some people might find disturbing. Some places provide headphones or earplugs to help block this out.


Ultrasound uses sound waves and their echoes to make pictures of internal organs or masses. For this test, a small, microphone-like instrument called a transducer is placed on the skin (which is first lubricated with a gel). It gives off sound waves and picks up the echoes as they bounce off the organs. A computer then converts the echoes into a black and white image on a screen.



Positron emission tomography (PET) scan





Last Medical Review: 08/04/2014
Last Revised: 08/04/2014