LEUKEMIA LYMPHOMA DEFINITION
Leukemia is cancer of the blood cells, usually affecting the white blood cells, which causes these cells to not work properly. There are four main types of leukemia.
Leukemia can occur in either the lymphoid or myeloid white blood cells. Cancer that develops in the lymphoid cells is called lymphocytic leukemia. Cancer that develops in the myeloid cells is called myelogenousleukemia. The disease can be either acute (begins abruptly and is usually short lived) or chronic (persists for a long period of time).
Acute leukemia involves new or immature cells, called blasts, which remain very immature and cannot perform their functions. The blasts increase in number rapidly, and the disease progresses quickly. In chronic leukemia, there are some blasts present, but they are more mature and can perform some of their functions. The cells grow more slowly so the disease progresses gradually.
Based on these findings, leukemia is then classified into one of the four main types of leukemias—acute myelogenousleukemia (AML), chronic myelogenousleukemia (CML), acute lymphocytic leukemia (ALL), or chronic lymphocytic leukemia (CLL). In addition to these, there are other types and subtypes of leukemia.
LEUKEMIA LYMPHOMA CAUSES
For most cancers, researchers are still trying to understand how they are caused. The same is true for lymphoma – doctors do not know what causes it, although it is more likely to occur in certain people.
Age – most non-Hodgkin lymphomas are in people 60 years of age and over
Sex – there are different rates of different types of non-Hodgkin’s lymphoma across the sexes
Ethnicity and location – in the US, African-Americans and Asian-Americans are less prone than white Americans, and the disease is more common in developed nations of the world
Chemicals and radiation – some chemicals used in agriculture have been linked, as has nuclear radiation exposure
Immune deficiency – for example, caused by HIV infection or in organ transplantation
Autoimmune disease, in which the immune system attacks the body’s own cells
Infection – certain viral and bacterial infections increase the risk. The Helicobacter Infection has been implicated, as has the Epstein Barr Virus (the virus that causes glandular fever)
See the American Cancer Society’s page for more detail on risk factors for non-Hodgkin’s lymphoma.
Infectious mononucleosis – infection with Epstein-Barr virus
Age – two specific groups are most affected: typically people in their 20s, and people over the age of 55 years
Sex – slightly more common in men
Location – most common in the US, Canada and northern Europe; least common in Asia
Family – if a sibling has the condition, the risk is slightly higher, and very high if there is an identical twin
Affluence – people from higher socioeconomic status are at greater risk
LEUKEMIA LYMPHOMA PATHOPHYSIOLOGY
Like all non-Hodgkin lymphomas (NHLs), lymphoblastic lymphoma is associated with exposure to radiation or pesticides and congenital or acquired immunosuppression. This condition arises from immature T cells in 85-90% of cases and immature B cells in the remainder of cases. The lymphoblasts infiltrate nodal structures or extranodal structures, especially the bone marrow, spleen, and central nervous system (CNS).
Lymphoblastic lymphoma is aggressive and progresses rapidly, presenting as stage IV disease in more than 70% of patients (see Staging). Gross lymphadenopathy impairs immunity, allows opportunistic infections, and may compress adjacent structures. In 30-50% of patients, the lymphoblasts infiltrate bone marrow, causing ineffective hematopoiesis. Many investigators have suggested that both lymphoblastic lymphoma and acute lymphoblastic leukemia (ALL) may be part of one clinical spectrum of a single malignant lymphoproliferative disorder.
Much of what is known about the molecular pathogenesis of lymphoblastic lymphoma has arisen from T-cell receptor analysis as well as nonrandom, recurrent chromosomal translocations. Approximately one third of tumors have translocations involving the alpha and delta T-cell receptor loci at band 14q11.2, the beta locus at band 7q35, and the gamma locus at band 7p14-15. These translocations result in juxtaposition T-cell receptor promoter and enhancer elements with various transcription factors, such as HOX11/TLX1, TAL1/SCL, TAL2, and LYL1, which lead to high levels of expression in precursor thymocytes. Molecular array studies have identified subtypes of the above noted abnormalities that may have distinct prognoses.
LEUKEMIA LYMPHOMA SYMPTOMS
Symptoms of lymphoma are similar to those of other diseases and afflictions. The most common symptom is a painless swelling in a lymph node (called lymphadenopathy). People often first go to the doctor because they think they have a cold or respiratory infection that will not go away. The neck or armpits are common places noticed first, but the swelling can occur in other parts of the body including the groin (that may cause swelling in the legs or ankles) or the abdomen (that can cause cramping and bloating). Some lymphoma patients notice no swelling at all while others may complain of night sweats, weight loss, chills, a lack of energy or itching. There is usually no pain involved, especially when the lymphoma is in the early stage of development.
Most people who have nonspecific complaints such as these will not have lymphoma. However, it is important that any person who has symptoms that persist see a doctor to confirm that no lymphoma or serious illness are present. The doctor will perform a complete physical examination and look for swollen lymph nodes under the chin, in the neck and tonsil area, on the shoulders and elbows, armpits, and in the groin. The doctor will also examine other parts of the body to see whether there is swelling or fluid in your chest or abdomen that could be caused by swollen lymph nodes.
You will be asked about pain and examined for any weakness or paralysis that could be an enlarged lymph node pressing against nerves or the spinal cord. Your abdomen will be examined to see whether any internal organs are enlarged, especially the spleen. If the doctor suspects lymphoma, he or she will likely order further tests including a biopsy, blood tests, x-rays and perhaps a bone marrow evaluation.
LEUKEMIA LYMPHOMA DIAGNOSIS
There is currently no active screening program for lymphoma, so it is only diagnosed when the person goes to their doctor with something that is concerning them. Because of the vagueness of the symptoms, doctors often reassure early cases of lymphoma, thinking that they are simple infections.
If symptoms persist, patients should go back to their doctor.
Doctors may investigate lymphoma when a patient presents the signs and symptoms.
They will start investigating lymphoma by “taking a history” – asking questions to help rule out other explanations for the symptoms. This will narrow down:
Possible risk factors
Other medical conditions.
LEUKEMIA LYMPHOMA TREATMENT
The prognosis (chance of recovery) and treatment options depend on the following:
- The stage of the cancer.
- The type of non-Hodgkin lymphoma.
- The amount of lactate dehydrogenase (LDH) in the blood.
- Whether there are certain changes in the genes.
- The patient’s age and general health.
- Whether the lymphoma has just been diagnosed or has recurred (come back).
For non-Hodgkin lymphoma during pregnancy, the treatment options also depend on:
- The wishes of the patient.
- Which trimester of pregnancy the patient is in.
- Whether the baby can be delivered early.
Some types of non-Hodgkin lymphoma spread more quickly than others do. Most non-Hodgkin lymphomas that occur during pregnancy are aggressive. Delaying treatment of aggressive lymphoma until after the baby is born may lessen the mother’s chance of survival. Immediate treatment is often recommended, even during pregnancy.