Diagnosing Leukemia

This information is useful for children and adults
portrait of a woman looking pensive, possibly as a result of receiving a diagnosis of leukemia

Diagnosing leukemia in its earliest stages can improve a patient’s prognosis. An accurate pathological diagnosis helps guide treatment.

Why Yale Medicine?
  • Yale Medicine is at the forefront of research into new and more effective treatments for leukemia, based on identification of each patient's certain cytogenetic features.
  • Yale Medicine's department of pathology has robust cytogenetic testing capabilities.
  • Cytogenetic findings are used to determine whether patients are eligible for clinical trials for emerging treatments offered by Yale Medicine.

Leukemia is cancer of bone marrow stem cells – immature cells that normally would develop into either red blood cells, white blood cells or platelets.

When someone has leukemia, the bone marrow produces abnormal blood cells that do not die when they become old, as normal, healthy cells do. These abnormal cells build up in the bone marrow and prevent normal blood cells from developing. Almost all leukemia begins in the bone marrow, and it usually spreads to the blood. Leukemia may also be found in other tissues, such as lymph nodes and the spleen.

Diagnosing leukemia in its earliest stages can improve a patient’s prognosis, so it is important to be tested as soon as possible if leukemia is suspected.

Just as there are several forms of blood cells, there are different types of leukemia.

Leukemia is classified as either acute or chronic, according to which type of blood cell is improperly reproduced.

“Acute leukemia is made of blasts, immature cells, while chronic leukemia is made of more mature cells,” says Alexa Siddon, MD, assistant professor of pathology at Yale Medicine. “Chronic leukemias tend to proliferate slower than acute leukemias, just because the blasts multiply very quickly. People with acute leukemia will become symptomatic more rapidly, in general.”

Leukemia that affects myeloid cells, which would normally develop into red blood cells, platelets or granulocytes (a specific type of white blood cell), is called myeloid leukemia or myelogenous or myeloblastic leukemia.

Leukemia that affects lymphoid cells, which would develop into lymphocytes, is called lymphoid leukemia or lymphoblastic or lymphocytic leukemia.