A bone marrow transplant, also called a stem cell transplant, is a treatment for some types of cancer. For example, you might have one if you have leukemia, multiple myeloma, or some types of lymphoma. Doctors also treat some blood diseases with stem cell transplants.
In the past, a stem cell transplant was more commonly called a bone marrow transplant because the stem cells were collected from the bone marrow. Today, stem cells are usually collected from the blood, instead of the bone marrow. For this reason, they are now often called stem cell transplants.