Acute lymphoblastic leukemia (ALL)
Acute lymphoblastic leukemia (ALL) is characterized by proliferation of immature lymphoid cells in bone marrow. Under normal conditions, lymphoid cells generate and develop mature T lymphocytes and B lymphocytes. These cells have an acquired and complex defensive role, making it possible to recognize the body's own structures and distinguish them from foreign ones.
Those anomalous immature lymphoid cells begin to proliferate out of control, invading the bone marrow and displacing normally functioning cells. These immature cells often infiltrate the bloodstream. When these cells enter the blood they lose their ability to perform their function, increasing the patient's susceptibility to infection. A lack of normal cells in the bone marrow lowers the production of red blood cells, which causes anemia, and lowered production of platelets makes a patient prone to bleeding.
Chromosomes are structures that contain the genetic material (DNA), which determines the cell aspect and function. Several chromosomal alterations have been described in lymphoblastic leukemia, including the Philadelphia chromosome.