Since leukemia is a cancer of the blood, skin complications don’t seem like they would be a prominent symptom. For most people with leukemia, they aren’t. However, leukemia cutis is a rare condition some people living with leukemia have to face. Here’s what it is and what it means.

What Is Leukemia Cutis?

In leukemia cutis, leukemia cells infiltrate the skin or the subcutaneous layers beneath the skin. These leukemia cells can be lymphoblasts, as in acute lymphocytic leukemia (ALL), or myeloblasts, as in acute myeloid leukemia (AML). All leukemia cells originate as defective stem cells in the bone marrow.

It is uncommon to have leukemia cutis as a first symptom of leukemia. Most cases occur after a diagnosis of leukemia. When it does appear as a first symptom, it is called aleukemic leukemia.

Leukemia cutis (DermNet NZ)

Most of the time, leukemia cutis presents as small papules (bumps) on the skin, but larger nodules can also appear. They are usually not painful, and they can be red, purple, or simply your normal skin color. If AML is the underlying diagnosis, profuse bleeding may occur.

The legs are the most common area where leukemia cutis shows up. The torso, arms, and head may also be affected. A dermatologist can diagnose leukemia cutis with a skin biopsy.

How Common Is Leukemia Cutis?

While the skin is the third most common place for leukemic involvement, after the blood and bone marrow, leukemia cutis is a rare condition. Only about 3 percent of those with leukemia will experience leukemia cutis. Most skin complications of leukemia are leukemids, lesions that are unrelated to leukemic infiltration of the skin.

Acute myeloid leukemia (AML) is the form of leukemia most commonly associated with leukemia cutis, which occurs in up to 15 percent of AML cases. Some types of AML are even more likely to include leukemia cutis; acute myelomonocytic leukemia has a 50 percent rate of leukemia cutis. The very rare adult T-cell leukemia/lymphoma is also associated with an increased risk of leukemia cutis.

Infants with congenital leukemia are more likely than adults to have leukemia cutis; around 25 percent to 30 percent will develop it. In infants, leukemia cutis is sometimes called “blueberry muffin syndrome” because of the blue-purple dots that appear on the skin.

Leukemia cutis is rarest in chronic leukemias, like chronic myeloid leukemia (CML) and chronic lymphocytic leukemia (CLL). Not all cases of leukemia cutis result from leukemia — people with other blood cancers such as myelodysplastic syndrome (MDS) and myeloma have also had it. There is also some evidence that certain chromosome abnormalities in cancer cells are associated with a higher rate of leukemia cutis.

How Is Leukemia Cutis Treated?

Treatment of leukemia cutis is always focused on treating the underlying leukemia. Because leukemia cutis is a sign of a systemic issue, local treatment of the skin alone is not considered effective.

As with many forms of leukemia, chemotherapy is the first line of treatment. If leukemia has been recently diagnosed, treatment can begin with induction chemotherapy, where an intensive medication course is administered. Localized radiation or surgery on the skin may be performed, along with chemotherapy, to address leukemia cutis lesions.

Some cases of leukemia cutis are associated with relapsed (return of cancer cells after treatment) or refractory (does not respond to treatment) leukemia. Doctors often recommend different treatment options for relapsed and refractory leukemia than those used when cancer is initially diagnosed.

One treatment for leukemia cutis that is not focused on the leukemia itself is the use of antimicrobials to prevent skin infection. Topical steroids and lidocaine mixtures are also considered helpful to ease leukemia cutis symptoms.

The Prognosis of Leukemia Cutis

Leukemia cutis is usually considered to be a poor prognosis sign. One study on 62 people with acute myeloid leukemia and leukemia cutis found they had a five-year survival rate of 8.6 percent, compared to 28.3 percent from a matched group with AML but no infiltration of the skin.

There is a recent development in the treatment of AML with leukemia cutis. Annamycin, a drug used to treat relapsed or refractory AML, has completed phase one clinical trials. One person with leukemia cutis in the trial had a substantial remission. Clinical trials on the drug are also underway in Europe. Hopefully, one day soon leukemia cutis will no longer be associated with a poor prognosis.