Definition
A lymphoblast is an immature lymphocyte, a precursor cell that develops into a mature lymphocyte (either a B cell or a T cell). Think of them as trainees in the immune system's army, learning the skills they need to defend your body. 🧑🎓 They are larger than mature lymphocytes and have a distinct appearance under a microscope. Lymphoblasts are normally found in the bone marrow and thymus, where lymphocytes develop. An elevated number of lymphoblasts in the blood can indicate certain types of leukemia or lymphoma, where these immature cells proliferate uncontrollably. They are the foundation of our adaptive immune response.