Leukemia cutis is a fairly rare form of leukemia that causes skin lesions. The appearance of the lesions varies significantly from person to person. There may be small or large lumps, thickened flat patches, or discolored dry skin.

Because of how varied leukemia cutis can be, it is possible for people to mistake the lesions for other skin conditions, such as psoriasis or eczema.

Lesions can appear before or after a leukemia diagnosis, but it usually develops after. Often, these indicate that the leukemia is at an advanced stage. Depending on where the lesions appear and how they look, it can be a difficult symptom to manage, affecting a person’s physical and mental health.

This article looks at leukemia cutis, including its symptoms, diagnosis, treatment, and outlook.

Leukemia is a type of cancer that affects blood-forming cells. These are cells that will go on to become a type of blood cell, such as a red blood cell, white blood cell, or platelet. If these cells become cancerous, they start growing out of control and can spread around the body via the bloodstream.

Leukemia cutis occurs when leukemia cells affect the skin, forming clusters within the layers of tissue. When this happens, visible patches or lesions appear. It is a rare symptom of leukemia, occurring in only 3% of people with leukemia.

Leukemia cutis may develop before or after someone receives their leukemia diagnosis. However, in 55–77% of cases, leukemia cutis develops after a leukemia diagnosis.

Doctors call leukemia cutis that precedes a diagnosis “aleukemic cutis.” People with aleukemic cutis go on to develop acute myeloid leukemia (AML).

Leukemia cutis lesions can vary in appearance. They may be:

  • small lumps (papules)
  • large lumps (nodules)
  • thickened flat patches (plaques)

Most of the time, lesions do not cause itching or soreness. They may be skin-colored, gray, red, brown, yellow, or blue, and commonly appear on the head, neck, trunk, or sites of injuries.

Rarely, leukemia cutis lesions may present as:

  • blisters
  • ulcers
  • dark ring-shaped rashes
  • eczema-like areas of thickened, inflamed skin
  • red or purple patches that occur due to bleeding beneath the skin

Some people may have additional leukemia symptoms alongside leukemia cutis. These can include:

  • fever
  • night sweats
  • feeling tired
  • easy bruising or bleeding
  • loss of appetite
  • weight loss

However, some forms of leukemia do not cause symptoms at first. Whether a person experiences other symptoms can depend on the type of leukemia they have and the speed it is growing.

Learn more about the types of leukemia.

Various factors can raise the chance of a person developing leukemia cutis. One of the most important is the type of leukemia a person has.

While any form of leukemia can cause skin symptoms, the subtypes most associated with it are:

  • myeloid leukemias, such as AML
  • B-cell leukemia/lymphomas, such as chronic lymphocytic leukemia (CLL)
  • T-cell leukemia/lymphomas

Of these, the type most likely to cause leukemia cutis is adult T-cell leukemia/lymphoma (ATLL). However, this type of leukemia is rare.

Leukemia cutis appears in 10–15% of AML cases. Specific AML subtypes, such as acute myelomonocytic leukemia, have a much greater risk of leukemia cutis.

Children with congenital leukemia are also prone to developing leukemia cutis, with up to 30% experiencing this symptom. Congenital leukemia is extremely rare, though, accounting for only 1% of childhood leukemias.

Certain environmental and genetic factors also increase the risk. People are more likely to develop leukemia, including leukemia cutis, if they become exposed to:

  • benzene
  • ionizing radiation
  • alkylating agents
  • certain viruses

Most people with leukemia cutis will already have a diagnosis of systemic leukemia, making the cause of the lesions clear. However, in some cases, people develop these lesions before they receive a leukemia diagnosis. This makes things more challenging, as the lesions may look similar to other conditions.

A doctor who thinks a person has leukemia cutis will look at the lesions and ask about a person’s symptoms. They will also perform diagnostic tests, which will typically include:

  • a complete blood count
  • a blood smear, where a medical professional examines a blood sample under a microscope
  • a bone marrow biopsy, which involves taking a small sample of bone marrow for examination
  • a skin biopsy, which involves taking a tissue sample from one of the lesions

Doctors may also request tests to determine how well the kidneys and liver are functioning, how well the blood clots, a complete metabolic profile, and for other biomarkers for cancer.

If a person has a fever, the doctor should test for infections immediately, as even minor infections in people with leukemia can be serious.

All individuals with leukemia cutis will develop leukemia. Because of this, doctors tend to use chemotherapy to treat leukemia cutis, because it kills cancerous cells around the body and not just in the skin. If effective, this systemic treatment will improve underlying leukemia and its impact on the skin.

Depending on the type and stage of leukemia, a person may also be eligible for targeted therapy or a stem cell transplant.

There are some therapies that specifically target the lesions and may remove the affected skin. This approach may involve a combination of the following treatments, alongside chemotherapy:

  • localized radiation
  • surgery
  • phototherapy

If a person has open wounds, doctors may prescribe antimicrobial medications to prevent infections. Other treatments can alleviate the symptoms of leukemia cutis by moisturizing the skin, numbing pain, and speeding up healing. For this, a person may use steroid creams, topical lidocaine, or menthol lotions.

Doctors may use radiation therapy for leukemia that comes back after going into remission, or for reducing symptoms if the cancer is not treatable.

While leukemia cutis is rare and is not fatal on its own, it often signifies an advanced stage of leukemia. This may mean a shorter survival time.

The presence of leukemia cutis signifies that someone may need intensive treatment as soon as possible. It may also indicate a complication of leukemia known as extramedullary disease (EMD). EMD occurs when leukemia involves several organs, such as the skin, lymphatic system, nervous system, and liver.

Leukemia cutis can also be difficult to cope with mentally, as it can alter a person’s appearance and make them feel self-conscious. On top of the demands of cancer treatment, this may affect someone’s mental health.

If someone is having trouble managing leukemia cutis, they can seek support from cancer support groups or therapists with experience treating people with chronic diseases.

Leukemia cutis occurs in people with leukemia and is the result of cancerous cells infiltrating the skin. This causes bumps, nodules, and lesions to form, which can vary in appearance. Most people with leukemia cutis will already have a leukemia diagnosis, but sometimes it appears beforehand.

Doctors treat leukemia cutis by addressing the systemic leukemia causing it. This involves chemotherapy, which kills cancerous cells. Localized treatments to remove the lesions or reduce the symptoms they cause may also help.