- Clinical science
Lymphomas are a type of cancer that arises from lymphocytes. These malignancies are classified into Hodgkin lymphomas, which are characterized by the presence of Reed-Sternberg cells, and non-Hodgkin lymphomas (NHLs), which comprise all other types of lymphoma. NHLs are further classified according to the cell type, i.e., B cells, T cells, and natural killer (NK) cells, and tumor grade. Low-grade tumors originate from mature cells that have a slow growth rate and an indolent clinical course. The most common low-grade B-cell lymphoma is follicular lymphoma, while the most common low-grade T-cell lymphomas are the cutaneous T-cell lymphomas such as mycosis fungoides. High-grade tumors, on the other hand, have a rapid growth rate and an aggressive clinical course. Certain subtypes of NHL are more common in children and young adults, such as Burkitt lymphoma. There is a variety of treatment options, depending on the type of lymphoma. Generally, treatment involves a combination of chemotherapy and radiation therapy. Limited disease low-grade tumors and high-grade NHL are treated with a curative approach. Advanced, low-grade tumors are treated with a palliative approach in symptomatic patients.
- NHL is the most common hematopoietic neoplasm
- Approx. 85% of lymphomas
- Incidence of all NHL increases with age; peak incidence > 50 years
- Subtype variance with age
- High-grade lymphomas more common in children and young adults (20–40 years)
Epidemiological data refers to the US, unless otherwise specified.
- Chromosomal translocations: most commonly t(14;18)
- Autoimmune diseases: Hashimoto thyroiditis, rheumatic disease
- Immunodeficiency: congenital immunodeficiencies, AIDS, history of chemotherapy and/or immunosuppressive therapy
- Environmental factors: aromatic hydrocarbons (e.g., benzene), radiation
B-cell lymphomas (85% of all NHL)
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T-cell lymphomas (15% of all NHL)
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|Aggressive (high-grade)|| |
- Insidious onset in low-grade lymphomas
- Painless lymphadenopathy
- Splenomegaly, hepatomegaly
- Extranodal disease; : most commonly involves the gastrointestinal tract, skin, thyroid, and CNS
- B symptoms (weight loss, fever, night sweats)
- Fatigue; , weakness, and signs of bone marrow involvement (anemia, bleeding, increased susceptibility to infections)
- Staging: similar to the one used for Hodgkin lymphoma (see the for details), but without B symptoms
- Chronic lymphocytic leukemia and multiple myeloma are classified separately.
Diagnosis of NHL is primarily based on medical history and clinical features and is confirmed with lymph node biopsy.
- Complete blood count
- Serum chemistry
- Virus serology testing (e.g., HIV serology)
- Confirmatory test: excisional lymph node biopsy : monomorphous, lymphocytic proliferation
- Bone marrow aspiration and biopsy in all patients for staging
- Biopsy samples from extranodal sites if extranodal disease is suspected
- X-ray and CT are required in all patients for staging
- Brain MRI for patients with neurologic symptoms
- Possibly PET-CT: initial evaluation for NHL staging, and post-treatment assessment
- Lumbar puncture with CSF examination (cytology; detection of EBV DNA) in case of
- See , , and
- Extranodal masses: solid tumors thymoma, teratoma (and other germ cell tumors), thyroid neoplasm, and terrible lymphoma
The 4 T's of a mediastinal mass: Thymoma, Teratoma (and other germ cell tumors), Thyroid neoplasm, and Terrible lymphoma!
The differential diagnoses listed here are not exhaustive.
There is a variety of treatment options, depending on the type of lymphoma. The choice of treatment is primarily based on the tumor grade, rather than the disease stage.
|Low-grade NHL||Limited stage||Curative|| |
|Advanced stage||Palliative|| |
|High-grade NHL||All stages||Curative|| |
- Low-grade lymphomas: median survival of 6–10 years
- High-grade lymphomas: survival typically several months (years in less aggressive variants)
- Indicators of poor prognosis: old age, number of involved nodal and extranodal sites, ↑ LDH, ↑ beta2 microglobulin