AML, or acute myeloid leukemia, and lymphoma are cancers of the immune system that develop in blood-forming stem cells produced in bone marrow. According to the National Cancer Institute, these stem cells divide into myeloid cells and lymphoid cells. Myeloid cells develop into red blood cells, blood-clotting platelet cells and white blood cells called granulocytes. Lymphoid cells develop into B-lymphocytes, T-lymphocytes and natural killer cells. AML is a specific cancer that develops in the myeloid cell line, and lymphomas develop in the lymphoid cell line.
AML
Acute myeloid leukemia is the most common type of acute leukemia in adults. The National Cancer Institute, or NCI, says AML may also be called acute myeloblastic leukemia, acute granulocytic leukemia, or acute nonlymphocytic leukemia. These conditions involve cancerous non-functional cells growing uncontrolled and eventually crowding out the functioning, normal blood cells. The result can be a low number of functional red blood cells resulting in anemia; low numbers of functioning infection-fighting white blood cells, resulting in infections; or too few blood-clotting platelets resulting in bleeding.
Lymphomas
Lymphomas form a family of cancers that are generated in the cells that make up the lymphatic system of immune cells and lymph vessels. According to the NCI there are two main forms of lymphoma, Hodgkin's lymphoma and non-Hodgkin's lymphoma. Hodgkin's lymphoma is marked by larger than normal lymphocytes, called Reed-Sternberg cells. Lymphomas that do not have the Reed-Sternberg cells are collectively called non-Hodgkin's lymphoma. There are many types of non-Hodgkin's lymphoma that are identified by the type of lymph system cells where the cancer originates. The American Cancer Society says there are so many types of non-Hodgkin's lymphoma that classifying them can be confusing even for doctors. Broadly speaking, the most common lymphomas include T-cell, B-cell and NK-cell lymphomas. Each of these have subtypes based on how they look under a microscope.
AML Risk Factors
According to the NCI, AML and lymphomas can occur in both children and adults. In adults AML risk factors include being male, smoking, previous chemotherapy or radiation therapy, having had childhood lymphoblastic leukemia, exposure to nuclear radiation or the chemical benzene, and having a blood disorder such as myelodysplastic syndrome.
Lymphoma Risk Factors
The American Cancer Society says risk factors for non-Hodgkin's lymphomas are the same for AML and include additional risk factors. Ethnicity increases risk for whites and lowers risk for African or Asian groups. People with past immune system deficiency or autoimmune diseases are at greater risk, as are people exposed to certain viruses such as the human T-cell leukemia/lymphoma virus and Epstein-Barr virus. Several studies have also linked obesity with risk of non-Hodgkin's lymphoma.
AML Symptoms
The NCI says symptoms of AML include fever, shortness of breath, easy bruising or bleeding, tiny freckle-like blood spots under the skin, constant weakness or tiredness, and unexplained weight loss or loss of appetite.
Lymphoma Symptoms
Lymphoma symptoms differ by type of lymphoma, according to the American Cancer Society. Lymphomas can cause swelling or tenderness of lymph nodes in skin or the abdomen. Other symptoms can include stomach pain, nausea or vomiting due to intestinal blockage. Thyroid lymphoma may cause coughing or difficulty breathing. A swollen thymus or lymph nodes in the chest may restrict blood flow within the large artery serving the heart, causing a bluish-red tinge to the arms, head and chest. Lymphomas affecting the brain can produce headaches, difficulty thinking, and sometimes personality changes or seizures. Skin lymphoma can cause red, extremely itchy skin or purple bumps.
