Acute myeloid leukemia (AML): Year of the Zebra 2026

Acute myeloid leukemia, or AML, is a type of blood cancer in which the bone marrow makes too many immature blood cells called myeloblasts. Even though it’s considered a rare disease, it’s the most common type of acute leukemia in adults, accounting for about 1% of all cancers in the United States.

Now, every cell type in the blood starts out as a hematopoietic stem cell, which is a multipotent cell that can develop into multiple different cell types, depending on the signals it receives. As a stem cell divides, it doesn’t immediately become a mature blood cell. Instead, it first commits to one of two main pathways, or cell lineages, called myeloid or lymphoid.

Cells that follow the myeloid lineage become red blood cells, which carry oxygen throughout the body; megakaryocytes that produce platelets, which help stop bleeding; and myeloblasts, which are large, immature white blood cells with a large central nucleus and very little surrounding cytoplasm. Under normal conditions, myeloblasts continue to mature into certain white blood cells, such as neutrophils and monocytes, which are especially important for fighting bacterial infections.

In AML, myeloblasts get stuck partway through development, so instead of maturing into these different cell types, they begin to rapidly multiply and pile up in the bone marrow. This crowding of the bone marrow leaves less space for the development of healthy, mature blood cells, such as red blood cells or platelets.

Affected cells usually have specific genetic mutations, such as pieces of DNA that are missing, duplicated, or rearranged. AML can be classified based on these genetic changes and how far those cells had progressed in their normal development before they got stuck.

Alright, now acute leukemias tend to be aggressive and fast-growing, meaning symptoms can appear and worsen over weeks rather than years. Since the bone marrow becomes filled with immature cells that don’t work properly, there isn’t enough room to make healthy blood cells.

This results in three main problems. First, when there are too few red blood cells, the body doesn’t get enough oxygen, and this can cause fatigue, weakness, shortness of breath, dizziness, and pale skin. This lack of sufficient amounts of red blood cells to carry oxygen throughout the body is known as anemia.

Next, when white blood cells are low or not functioning normally, the immune system becomes weaker. People with AML may get frequent infections, have unexplained fevers, or find that infections are harder to recover from.