What are Leukemia and Lymphoma?

Leukemia and lymphoma are both considered cancers of the blood, though leukemia starts in the bone marrow, where blood cells are made, and lymphoma starts in the lymphatic system, which is responsible for fighting disease along with your immune system.^{1, 2, 3}

Cancer is a disease that begins in the cells of our body, and causes them to behave abnormally. Instead of growing, working, reproducing and then dying in a normal cycle, cancer cells grow and divide uncontrollably. In organ cancers, abnormal cells cause lumps or tumours, but leukemia and lymphoma don’t usually do that, because they form abnormal cells that circulate in the blood, bone marrow, and lymphatic system.³

There are four different types of leukemia:

• Acute myelogenous leukemia (AML)
• Acute lymphocytic leukemia (ALL)
• Chronic myelogenous leukemia (CML)
• Chronic lymphocytic leukemia (CLL)

Acute leukemia progresses rapidly without treatment, while chronic leukemia is more slow to develop compared to the acute form. Myelogenous, or myeloid, refers to the fact that the cancer begins in bone marrow cells that go on to produce blood cells or platelets. Lymphocytic, or lymphoblastic, refers to cancer that normally begins in cells that go on to produce lymphocytes, which are a special type of white blood cell.¹

There are two main types of lymphoma:

• Hodgkin lymphoma
• Non-Hodgkin Lymphoma

Hodgkin lymphoma is distinguished from other lymphomas partly by the presence of Reed-Sternberg cells, which are large, malignant cells named for the scientist who discovered them. Non-Hodgkin lymphoma is the name for a group of other lymphomas that each have their own unique characteristics.²