Lymphoid leukemias are a group of

leukemia Leukemia ( also spelled leukaemia; pronounced ) is a group of blood cancers that usually begin in the bone marrow and produce high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or '' ...

s affecting circulating

lymphocyte A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include T cells (for cell-mediated and cytotoxic adaptive immunity), B cells (for humoral, antibody-driven adaptive immunity), an ...

s, a type of

white blood cell White blood cells (scientific name leukocytes), also called immune cells or immunocytes, are cells of the immune system that are involved in protecting the body against both infectious disease and foreign entities. White blood cells are genera ...

. The lymphocytic leukemias are closely related to

lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). The name typically refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlarged lymph node ...

s of the lymphocytes, to the point that some of them are unitary disease entities that can be called by either name (for example,

adult T-cell leukemia/lymphoma Adult T-cell leukemia/lymphoma (ATL or ATLL) is a rare cancer of the immune system's T-cells caused by human T cell leukemia/lymphotropic virus type 1 ( HTLV-1). All ATL cells contain integrated HTLV-1 provirus further supporting that causal role ...

). Such diseases are all

lymphoproliferative disorders Lymphoproliferative disorders (LPDs) refer to a specific class of diagnoses, comprising a group of several conditions, in which lymphocytes are produced in excessive quantities. These disorders primarily present in patients who have a compromised ...

. Most lymphoid leukemias involve a particular subtype of lymphocytes, the

B cell B cells, also known as B lymphocytes, are a type of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or inserted into the plasm ...

Classification

Historically, they have been most commonly divided by the stage of maturation at which the clonal (neoplastic) lymphoid population stopped maturing: *

Acute lymphoblastic leukemia Acute lymphoblastic leukemia (ALL) is a cancer of the Lymphocyte, lymphoid line of blood cells characterized by the development of large numbers of lymphoblast, immature lymphocytes. Symptoms may include feeling tired, pale skin color, fever, ...

Chronic lymphocytic leukemia Chronic lymphocytic leukemia (CLL) is a type of cancer that affects the blood and bone marrow. In CLL, the bone marrow makes too many lymphocytes, which are a type of white blood cell. In patients with CLL, B cell lymphocytes can begin to colle ...

However, the influential WHO Classification (published in 2001) emphasized a greater emphasis on cell lineage. To this end, lymphoid leukemias can also be divided by the type of cells affected: * B-cell leukemia * T-cell leukemia * NK-cell leukemia The most common type of lymphoid leukemia is B-cell chronic lymphocytic leukemia.

B-cell leukemias

B-cell leukemia describes several different types of lymphoid leukemia which affect

s. Other types include (with

ICD-O The International Classification of Diseases for Oncology (ICD-O) is a domain-specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. This classification is widely used by canc ...

code): * 9826/3 –

, mature B-cell type * 9833/3 –

B-cell prolymphocytic leukemia B-cell prolymphocytic leukemia, referred to as B-PLL, is a rare blood cancer. It is a more aggressive, but still treatable, form of leukemia. Specifically, B-PLL is a prolymphocytic leukemia (PLL) that affects prolymphocytes – immature forms ...

* 9940/3 –

Hairy cell leukemia Hairy cell leukemia is an uncommon hematological malignancy characterized by an accumulation of abnormal B lymphocytes. The incidence of hairy cell leukemia (HCL) is 0.28-0.30 cases per 100,000 people in Europe and the United States and the pre ...

T-cell leukemias

T-cell leukemia describes several different types of lymphoid leukemias which affect

T cell T cells (also known as T lymphocytes) are an important part of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their cell ...

s. The most common T-cell leukemia is precursor T-cell lymphoblastic leukemia. It causes 15% of acute leukemias in childhood, and also 40% of lymphomas in childhood. It is most common in

adolescent Adolescence () is a transitional stage of human physical and psychological development that generally occurs during the period from puberty to adulthood (typically corresponding to the age of majority). Adolescence is usually associated w ...

males. Its morphology is identical to that of ''precursor B-cell lymphoblastic leukemia''. Cell markers include TdT, CD2, CD7. It often presents as a mediastinal mass because of involvement of the

thymus The thymus (: thymuses or thymi) is a specialized primary lymphoid organ of the immune system. Within the thymus, T cells mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. The thymus ...

. It is highly associated with NOTCH1 mutations. Other types include: * Large granular lymphocytic leukemia *

Adult T-cell leukemia/lymphoma Adult T-cell leukemia/lymphoma (ATL or ATLL) is a rare cancer of the immune system's T-cells caused by human T cell leukemia/lymphotropic virus type 1 ( HTLV-1). All ATL cells contain integrated HTLV-1 provirus further supporting that causal role ...

T-cell prolymphocytic leukemia T-cell-prolymphocytic leukemia (T-PLL) is a mature T-cell leukemia with aggressive behavior and predilection for blood, bone marrow, lymph nodes, liver, spleen, and skin involvement. T-PLL is a very rare leukemia, primarily affecting adults over t ...

In practice, it can be hard to distinguish T-cell leukemia from

T-cell lymphoma T-cell lymphoma is a rare form of cancerous lymphoma affecting T cell, T-cells. Lymphoma arises mainly from the uncontrolled proliferation of lymphocytes, such as T-cells, and can become cancerous. T-cell lymphoma is categorized under Non-Hodgkin ...

, and they are often grouped together.

NK cell leukemia

Aggressive NK-cell leukemia (ANKL) is a lymphoid leukemia that is a deficiency NK cells. Not very much is known about this disease due to its rarity, but it is highly aggressive. A majority of patients with NK cell leukemia die within a year of diagnosis, and for ANKL in particular, half of patients die within two months.

Diagnosis

The requirements for diagnosing ANKL are as follows: # Immature-looking NK cells # Certain immunophenotypes # Germline configuration genes: TCR-β and IgH # Restricted cytotoxicity The

T-cell receptor The T-cell receptor (TCR) is a protein complex, located on the surface of T cells (also called T lymphocytes). They are responsible for recognizing fragments of antigen as peptides bound to major histocompatibility complex (MHC) molecules. ...

(TCR) is an important factor when ANKL is being diagnosed along with T-cell leukemia. The TCR gene transcripts are normally positive for ANKL. Current Research is attempting to find the causation of ANKL. So far, the researchers have concluded that lineage of the T-cell receptor gene does not predict the behavior of the disease.

Treatment

ANKL is treated similarly to most

B-cell lymphoma The B-cell lymphomas are types of lymphoma affecting B cells. Lymphomas are Tumors of the hematopoietic and lymphoid tissues, "blood cancers" in the lymph nodes. They develop more frequently in older adults and in immunocompromised individuals. ...

Anthracycline Anthracyclines are a class of drugs used in cancer chemotherapy that are extracted from '' Streptomyces peucetius'' bacterium. These compounds are used to treat many cancers, including leukemias, lymphomas, breast, stomach, uterine, ovarian, b ...

-containing chemotherapy regimens are commonly offered as the initial therapy. Some patients may receive a

stem cell transplant Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood, in order to replicate inside a patient and produce a ...

Overall survival Survival rate is a part of survival analysis. It is the proportion of people in a study or treatment group still alive at a given period of time after diagnosis. It is a method of describing prognosis in certain disease conditions, and can be use ...

depends on the

stage Stage, stages, or staging may refer to: Arts and media Acting * Stage (theatre), a space for the performance of theatrical productions * Theatre, a branch of the performing arts, often referred to as "the stage" * ''The Stage'', a weekly Brit ...

of the cancer when treatment is initiated, and on a composite of numerous risk factors. The median time from diagnosis to death is less than 1 year in patients overall. Patients diagnosed early and/or with fewer risk factors can sometimes enter complete remission and expect much longer survival.

Diagnosis

Flow cytometry Flow cytometry (FC) is a technique used to detect and measure the physical and chemical characteristics of a population of cells or particles. In this process, a sample containing cells or particles is suspended in a fluid and injected into the ...

is a diagnostic tool in order to count/visualize the amount of lymphatic cells in the body. T cells, B cells and NK cells are nearly impossible to distinguish under a microscope, therefore one must use a flow cytometer to distinguish them.

Treatment

Targeted therapy

Several molecular tumor profiling protocols have been initiated in Europe (e.g., MOSCATO-01, iTHER, and ESMART) to identify actionable lesions for targeted treatment in specific subgroups of patients.

NK cell therapy

Natural killer (NK) cell therapy is used in pediatrics for children with relapsed lymphoid leukemia. These patients normally have a resistance to chemotherapy, therefore, in order to continue on, must receive some kind of therapy. In some cases, NK cell therapy is a choice. NK cells are known for their ability to eradicate tumor cells without any prior sensitization to them. One problem when using NK cells in order to fight off lymphoid leukemia is the fact that it is hard to amount enough of them to be effective. One can receive donations of NK cells from parents or relatives through bone marrow transplants. There are also the issues of cost, purity and safety. Unfortunately, there is always the possibility of Graft vs host disease while transplanting bone marrow. NK cell therapy is a possible treatment for many different cancers such as Malignant glioma.

References

External links

{{Lymphoid malignancy Leukemia