Of all cancers involving the same class of blood cell, 2.3% of cases are Burkitt lymphoma. Epstein-Barr virus infection is strongly correlated with this cancer.

Histologic transformation to diffuse large B-cell lymphoma (DLBCL) can occur in up to 12% of cases. After transformation, neoplastic cells carry monoclonal immunoglobulin gene rearrangements. Histological transformation may lead to poor prognosis and therefore repeat biopsy is required at relapse.

One study found a transformation rate of 7.6%, and suggested that prior exposure to chemotherapy and a presentation with splenic involvement were associated with increased risks of transformation.

One study has suggested improved overall survival in response to chemotherapy for African Americans.

6% of non-Hodgkin lymphoma cases are mantle cell lymphoma. As of 2015, the ratio of males to females affected is about 4:1.

The lymphoma is more common in the young and in males.

A 2008 study found an increased risk of ALCL of the breast in women with silicone breast implants (protheses), although the overall risk remained exceedingly low due to the rare occurrence of the tumor.

The Center for Disease Control and Prevention (CDC) included certain types of non-Hodgkin's lymphoma as AIDS-defining cancers in 1987. Immune suppression rather than HIV itself is implicated in the pathogenesis of this malignancy, with a clear correlation between the degree of immune suppression and the risk of developing NHL. Additionally, other retroviruses such as HTLV may be spread by the same mechanisms that spread HIV, leading to an increased rate of co-infection. The natural history of HIV infection has been greatly changed over time. As a consequence, rates of non-Hodgkin's lymphoma (NHL) in people infected with HIV has significantly declined in recent years.

Of all cancers involving the same class of blood cell, 2% of cases are cutaneous T cell lymphomas. CTCL is more common in men and in African-American people. The incidence of CTCL in men is 1.6 times higher than in women.

There is some evidence of a relationship with human T-lymphotropic virus (HTLV) with the adult T-cell leukemia/lymphoma subtype. No definitive link between any viral infection or environmental factor has been definitely shown with other CTCL subtypes.

The most common chemotherapy used for non-Hodgkin lymphoma is R-CHOP.

Treatment of Hodgkin's disease has been improving over the past few decades. Recent trials that have made use of new types of chemotherapy have indicated higher survival rates than have previously been seen. In one recent European trial, the 5-year survival rate for those patients with a favorable prognosis (FFP) was 98%, while that for patients with worse outlooks was at least 85%.

In 1998, an international effort identified seven prognostic factors that accurately predict the success rate of conventional treatment in patients with locally extensive or advanced stage Hodgkin's lymphoma. Freedom from progression (FFP) at 5 years was directly related to the number of factors present in a patient. The 5-year FFP for patients with zero factors is 84%. Each additional factor lowers the 5-year FFP rate by 7%, such that the 5-year FFP for a patient with 5 or more factors is 42%.

The adverse prognostic factors identified in the international study are:

- Age ≥ 45 years

- Stage IV disease

- Hemoglobin < 10.5 g/dl

- Lymphocyte count < 600/µl or < 8%

- Male

- Albumin < 4.0 g/dl

- White blood count ≥ 15,000/µl

Other studies have reported the following to be the most important adverse prognostic factors: mixed-cellularity or lymphocyte-depleted histologies, male sex, large number of involved nodal sites, advanced stage, age of 40 years or more, the presence of B symptoms, high erythrocyte sedimentation rate, and bulky disease (widening of the mediastinum by more than one third, or the presence of a nodal mass measuring more than 10 cm in any dimension.)

More recently, use of positron emission tomography (PET) early after commencing chemotherapy has demonstrated to have powerful prognostic ability. This enables assessment of an individual's response to chemotherapy as the PET activity switches off rapidly in patients who are responding. In this study, after two cycles of ABVD chemotherapy, 83% of patients were free of disease at 3 years if they had a negative PET versus only 28% in those with positive PET scans. This prognostic power exceeds conventional factors discussed above. Several trials are underway to see if PET-based risk adapted response can be used to improve patient outcomes by changing chemotherapy early in patients who are not responding.

Unlike some other lymphomas, whose incidence increases with age, Hodgkin's lymphoma has a bimodal incidence curve; that is, it occurs most frequently in two separate age groups, the first being young adulthood (age 15–35) and the second being in those over 55 years old although these peaks may vary slightly with nationality. Overall, it is more common in males, except for the nodular sclerosis variant, which is slightly more common in females. The annual incidence of Hodgkin's lymphoma is 2.7 per 100,000 per persons per year, and the disease accounts for slightly less than 1% of all cancers worldwide.

In 2010, globally it resulted in about 18,000 deaths down from 19,000 in 1990.

The incidence of Hodgkin's lymphoma is increased in patients with HIV infection. In contrast to many other lymphomas associated with HIV infection it occurs most commonly in patients with higher CD4 T cell counts.

Lymphoma is the most common form of hematological malignancy, or "blood cancer", in the developed world.

Taken together, lymphomas represent 5.3% of all cancers (excluding simple basal cell and squamous cell skin cancers) in the United States and 55.6% of all blood cancers.

According to the U.S. National Institutes of Health, lymphomas account for about 5%, and Hodgkin lymphoma in particular accounts for less than 1% of all cases of cancer in the United States.

Because the whole system is part of the body's immune system, patients with a weakened immune system such as from HIV infection or from certain drugs or medication also have a higher incidence of lymphoma.

Treatment with dose-adjusted EPOCH with rituximab has shown promising initial results in a small series of patients (n=17), with a 100% response rate, and 100% overall survival and progression-free survival at 28 months (median follow-up).

The prognosis varies according with the type of ALCL. During treatment, relapses may occur but these typically remain sensitive to chemotherapy.

Those with ALK positivity have better prognosis than ALK negative ALCL. It has been suggested that ALK-negative anaplastic large-cell lymphomas derive from other T-cell lymphomas that are morphologic mimics of ALCL in a final common pathway of disease progression. Whereas ALK-positive ALCLs are molecularly characterized and can be readily diagnosed, specific immunophenotypic or genetic features to define ALK-negative ALCL are missing and their distinction from other T-cell non-Hodgkin lymphomas (T-NHLs) remains controversial, although promising diagnostic tools for their recognition have been developed and might be helpful to drive appropriate therapeutic protocols.

Systemic ALK+ ALCL 5-year survival: 70–80%.

Systemic ALK- ALCL 5-year survival: 15–45%.

Primary Cutaneous ALCL: Prognosis is good if there is not extensive involvement regardless of whether or not ALK is positive with an approximately 90% 5-year survival rate.

Breast implant-associated ALCL has an excellent prognosis when the lymphoma is confined to the fluid or to the capsule surrounding the breast implant. This tumor can be recurrent and grow as a mass around the implant capsule or can extend to regional lymph nodes if not properly treated.

This rare form of leukemia is more common among Asians in comparison to other ethnic groups. It is typically diagnosed in adolescents and young adults, with a slight predominance in males.

Of all cancers involving the same class of blood cell, 8% of cases are mature T cell lymphomas. Of such cases, 2% are precursor T lymphoblastic and 2% are cutaneous T cell lymphomas.

Orbital lymphoma accounts for 55% of malignant orbital tumors in adults. In one study, this was 10% of patients presenting with orbital tumors or similar lesions. Orbital lymphoma is more prevalent in Asia and Europe than in the United States.

Although intraocular lymphoma is rare, the number of cases per year is rising, affecting mainly people in their seventies and immunocompromised patients. A recent study has shown that ocular lymphoma is more prevalent in women than men.

The survival rate is approximately 60% after 5 years.

In the United States, about 500 patients are diagnosed with Richter's transformation each year.

The typical patient with angioimmunoblastic T-cell lymphoma (AITL) is either middle-aged or elderly, and no gender preference for this disease has been observed. AITL comprises 15–20% of peripheral T-cell lymphomas and 1–2% of all non-Hodgkin lymphomas.

Additionally, some researchers separate out lymphomas that appear to result from other immune system disorders, such as AIDS-related lymphoma.

Classic Hodgkin's lymphoma and nodular lymphocyte predominant Hodgkin's lymphoma are now considered forms of B-cell lymphoma.

The prognosis is generally poor. The "RS score" (Richter syndrome score), which is an estimate of the patient's prognosis, is based on the patient's performance status, LDH, platelet count, the size of the lymphoma tumors, and the number of prior therapies already received. Overall, the median survival is between five and eight months. Untreated, RS is invariably fatal.

The Hodgkin's lymphoma variant of Richter's carries a better prognosis than the predominant diffuse large B-cell lymphoma type, but a worse prognosis than a "de novo" case of Hodgkin's.

A second regimen under evaluation is R-EPOCH (rituximab with etoposide-prednisone-vincristine-doxorubicin-cyclophosphamide), which demonstrated a 5-year progression-free survival (PFS) of 79% in a phase II trial. A phase III trial, CALGB 50303, is now comparing R-EPOCH with R-CHOP in patients with newly diagnosed DLBCL.

One area of active research is on separating patients into groups based on their prognosis and how likely they are to benefit from different drugs. Methods like gene expression profiling and next-generation sequencing may result in more effective and more personalized treatment.

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

B-cell lymphomas include both Hodgkin's lymphomas and most non-Hodgkin lymphomas. They are typically divided into low and high grade, typically corresponding to indolent (slow-growing) lymphomas and aggressive lymphomas, respectively. As a generalisation, indolent lymphomas respond to treatment and are kept under control (in remission) with long-term survival of many years, but are not cured. Aggressive lymphomas usually require intensive treatments, with some having a good prospect for a permanent cure.

Prognosis and treatment depends on the specific type of lymphoma as well as the stage and grade. Treatment includes radiation and chemotherapy. Early-stage indolent B-cell lymphomas can often be treated with radiation alone, with long-term non-recurrence. Early-stage aggressive disease is treated with chemotherapy and often radiation, with a 70-90% cure rate. Late-stage indolent lymphomas are sometimes left untreated and monitored until they progress. Late-stage aggressive disease is treated with chemotherapy, with cure rates of over 70%.

The two types of lymphoma research are clinical or translational research and basic research. Clinical/translational research focuses on studying the disease in a defined and generally immediately patient-applicable way, such as testing a new drug in patients. Studies may focus on effective means of treatment, better ways of treating the disease, improving the quality of life for patients, or appropriate care in remission or after cures. Hundreds of clinical trials are being planned or conducted at any given time.

Basic science research studies the disease process at a distance, such as seeing whether a suspected carcinogen can cause healthy cells to turn into lymphoma cells in the laboratory or how the DNA changes inside lymphoma cells as the disease progresses. The results from basic research studies are generally less immediately useful to patients with the disease, but can improve scientists' understanding of lymphoma and form the foundation for future, more effective treatments.

The overall 5-year survival rate for MCL is generally 50% (advanced stage MCL) to 70% (for limited-stage MCL).

Prognosis for individuals with MCL is problematic and indexes do not work as well due to patients presenting with advanced stage disease. Staging is used but is not very informative, since the malignant B-cells can travel freely though the lymphatic system and therefore most patients are at stage III or IV at diagnosis. Prognosis is not strongly affected by staging in MCL and the concept of metastasis does not really apply.

The Mantle Cell Lymphoma International Prognostic Index (MIPI) was derived from a data set of 455 advanced stage MCL patients treated in series of clinical trials in Germany/Europe. Of the evaluable population, approximately 18% were treated with high-dose therapy and stem cell transplantation in first remission. The MIPI is able to classify patients into three risk groups: low risk (median survival not reached after median 32 months follow-up and 5-year OS rate of 60%), intermediate risk (median survival 51 months) and high risk (median survival 29 months). In addition to the 4 independent prognostic factors included in the model, the cell proliferation index (Ki-67) was also shown to have additional prognostic relevance. When the Ki67 is available, a biologic MIPI can be calculated.

MCL is one of the few NHLs that can cross the boundary into the brain, yet it can be treated in that event.

There are a number of prognostic indicators that have been studied. There is not universal agreement on their importance or usefulness in prognosis.

Ki-67 is an indicator of how fast cells mature and is expressed in a range from about 10% to 90%. The lower the percentage, the lower the speed of maturity, and the more indolent the disease. Katzenberger et al. Blood 2006;107:3407 graphs survival versus time for subsets of patients with varying Ki-67 indices. He shows median survival times of about one year for 61-90% Ki-67 and nearly 4 years for 5-20% Ki-67 index.

MCL cell types can aid in prognosis in a subjective way. Blastic is a larger cell type. Diffuse is spread through the node. Nodular are small groups of collected cells spread through the node. Diffuse and nodular are similar in behavior. Blastic is faster growing and it is harder to get long remissions. Some thought is that given a long time, some non-blastic MCL transforms to blastic. Although survival of most blastic patients is shorter, some data shows that 25% of blastic MCL patients survive to 5 years. That is longer than diffuse type and almost as long as nodular (almost 7 yrs).

Beta-2 microglobulin is another risk factor in MCL used primarily for transplant patients. Values less than 3 have yielded 95% overall survival to 6 yrs for auto SCT where over 3 yields a median of 44 most overall survival for auto SCT (Khouri 03). This is not yet fully validated.

Testing for high levels of LDH in NHL patients is useful because LDH is released when body tissues break down for "any" reason. While it cannot be used as a sole means of diagnosing NHL, it is a surrogate for tracking tumor burden in those diagnosed by other means. The normal range is approximately 100-190.

The T-cell lymphomas are four types of lymphoma that affect T cells. These account for about one in ten cases of non-Hodgkin lymphoma.

They can be associated with Epstein Barr virus and Human T-cell leukemia virus-1.