Treatment of some other, more aggressive, forms of lymphoma can result in a cure in the majority of cases, but the prognosis for patients with a poor response to therapy is worse. Treatment for these types of lymphoma typically consists of aggressive chemotherapy, including the CHOP or R-CHOP regimen. A number of people are cured with first-line chemotherapy. Most relapses occur within the first two years, and the relapse risk drops significantly thereafter. For people who relapse, high-dose chemotherapy followed by autologous stem cell transplantation is a proven approach.

Treatment is dependent if the lymphoma is causing issues in regards to the overall health of the individual. Since this a slow moving cancer, many patients start treatment when the symptoms appear. If the individual tests positive for hepatitis C, then anti-viral treatment is suggested since it will often get rid of the lymphoma as well. If further treatment is required the options include chemotherapy, monoclonal antibodies, and/or radiation. Radiation therapy is used for stage I and II nodal marginal zone NHL. Clinical trials show success in treatment when using drugs such as bendamustine and lenalidomida in combination with rituximab.

The original route of treatment for MALT is antibiotics to treat an underlying infection such as H.pylori. H.pylori is directly related to the development of this lymphoma. Since most patients respond well to this treatment, then no further treatment is needed. If the lymphoma is not linked to an infection, then radiotherapy and chemotherapy are needed. If the disease is more advanced, then immunoradiotherapy with chemotherapy will be needed. Among the common first-line treatments are bendamustine plus rituximab and R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone). Recently, antibiotic therapy such as doxycycline has been shown to be effective in marginal zone lymphoma that affects the area around the eye ("ocular adnexal marginal zone lymphoma").

Patients with early stage disease (IA or IIA) are effectively treated with radiation therapy or chemotherapy. The choice of treatment depends on the age, sex, bulk and the histological subtype of the disease. Adding localised radiation therapy after the chemotherapy regimen may provide a longer progression-free survival compared with chemotherapy treatment alone. Patients with later disease (III, IVA, or IVB) are treated with combination chemotherapy alone. Patients of any stage with a large mass in the chest are usually treated with combined chemotherapy and radiation therapy.

It should be noted that the common non-Hodgkin's treatment, rituximab (which is a monoclonal antibody against CD20) is not routinely used to treat Hodgkin's lymphoma due to the lack of CD20 surface antigens in most cases. The use of rituximab in Hodgkin's lymphoma, including the lymphocyte predominant subtype has been recently reviewed.

Although increased age is an adverse risk factor for Hodgkin's lymphoma, in general elderly patients without major comorbidities are sufficiently fit to tolerate standard therapy, and have a treatment outcome comparable to that of younger patients. However, the disease is a different entity in older patients and different considerations enter into treatment decisions.

For Hodgkin's lymphomas, radiation oncologists typically use external beam radiation therapy (sometimes shortened to EBRT or XRT). Radiation oncologists deliver external beam radiation therapy to the lymphoma from a machine called linear accelerator which produces high energy X Rays and Electrons. Patients usually describe treatments as painless and similar to getting an X-ray. Treatments last less than 30 minutes each.

For lymphomas, there are a few different ways radiation oncologists target the cancer cells. Involved field radiation is when the radiation oncologists give radiation only to those parts of the patient's body known to have the cancer. Very often, this is combined with chemotherapy. Radiation therapy directed above the diaphragm to the neck, chest or underarms is called mantle field radiation. Radiation to below the diaphragm to the abdomen, spleen or pelvis is called inverted-Y field radiation. Total nodal irradiation is when the therapist gives radiation to all the lymph nodes in the body to destroy cells that may have spread.

The high cure rates and long survival of many patients with Hodgkin's lymphoma has led to a high concern with late adverse effects of treatment, including cardiovascular disease and second malignancies such as acute leukemias, lymphomas, and solid tumors within the radiation therapy field. Most patients with early-stage disease are now treated with abbreviated chemotherapy and involved-field radiation therapy rather than with radiation therapy alone. Clinical research strategies are exploring reduction of the duration of chemotherapy and dose and volume of radiation therapy in an attempt to reduce late morbidity and mortality of treatment while maintaining high cure rates. Hospitals are also treating those who respond quickly to chemotherapy with no radiation.

In childhood cases of Hodgkin's lymphoma, long-term endocrine adverse effects are a major concern, mainly gonadal dysfunction and growth retardation. Gonadal dysfunction seems to be the most severe endocrine long-term effect, especially after treatment with alkylating agents or pelvic radiotherapy.

An example antibody for use in immunotherapy is Rituximab. Rituximab has specific use in treatment of NLPHL as it is a chimeric monoclonal antibody against the protein CD20. Studies indicate Rituximab offers potential in relapsed or refractory patients, and also in front-line treatment especially in advanced stages. Because of a tendency for relapse, maintenance treatment such as every 6 months for 2 years is suggested. Rituximab has been shown to improve patient outcomes after histological transformation.

Many low-grade lymphomas remain indolent for many years. Treatment of the nonsymptomatic patient is often avoided. In these forms of lymphoma, such as follicular lymphoma, watchful waiting is often the initial course of action. This is carried out because the harms and risks of treatment outweigh the benefits. If a low-grade lymphoma is becoming symptomatic, radiotherapy or chemotherapy are the treatments of choice; although they do not cure the lymphoma, they can alleviate the symptoms, particularly painful lymphadenopathy. Patients with these types of lymphoma can live near-normal lifespans, but the disease is incurable. Some centers advocate the use of single agent rituximab in the treatment of follicular lymphoma rather than the wait and watch approach. Watchful waiting is not a good strategy for all patients, as it leads to significant distress and anxiety in some patients. It has been equated with watch and worry.

Possible options such as anthracycline-containing regimens include ABVD, BEACOPP and CHOP. Results of a trial with COPP/ABV in children suggested positive results with chemotherapy alone are possible without the need for radiation therapy. Optimal chemotherapy is a topic for debate, for example there is evidence of support for treatment with R-CHOP instead of ABVD, results showing high rates (40%) of relapse after 10 years since ABVD chemotherapy. BEACOPP has higher reported toxicity risk.

Breast implant-associated ALCL is a recently recognized lymphoma and definitive management and therapy is under evaluation. However, it appears that removal of the implant, and resection of the capsule around the implant as well as evaluation by medical and surgical oncologists are cornerstones. Still under evaluation is the extent of capsulectomy: partial versus complete capsulectomy; similarly it is not defined the significance of replacement of the implant in the affected breast, or the removal of contralateral implant. Similarly, the value of radiation therapy and chemotherapy are under evaluation.

Currently, there is a drug, LDK378, undergoing Phase III clinical trials at Vanderbilt University that targets ALK positive small cell lung cancer, and has showed clinical promise in its previous clinical trials. Because approximately 70% of ALCL neoplasms are also ALK positive, there is hope that similar highly selective and potent ALK inhibitors may be used in the future to treat ALK positive cases of ALCL.

Chemotherapy is widely used as frontline treatment, and often is not repeated in relapse due to side effects. Alternate chemotherapy is sometimes used at first relapse. For frontline treatment, CHOP with rituximab is the most common chemotherapy, and often given as outpatient by IV. A stronger chemotherapy with greater side effects (mostly hematologic) is HyperCVAD, often given as in-patient, with rituximab and generally to fitter patients (some of which are over 65). HyperCVAD is becoming popular and showing promising results, especially with rituximab. It can be used on some elderly (over 65) patients, but seems only beneficial when the baseline Beta-2-MG blood test was normal. It is showing better complete remissions (CR) and progression free survival (PFS) than CHOP regimens. A less intensive option is bendamustine with rituximab.

Second line treatment may include fludarabine, combined with cyclophosphamide and/or mitoxantrone, usually with rituximab. Cladribine and clofarabine are two other drugs being investigated in MCL. A relatively new regimen that uses old drugs is PEP-C, which includes relatively small, daily doses of prednisone, etoposide, procarbazine, and cyclophosphamide, taken orally, has proven effective for relapsed patients. According to John Leonard, PEP-C may have anti-angiogenetic properties, something that he and his colleagues are testing through an ongoing drug trial.

Another approach involves using very high doses of chemotherapy, sometimes combined with total body irradiation (TBI), in an attempt to destroy all evidence of the disease. The downside to this is the destruction of the patients' entire immune system as well, requiring rescue by transplantation of a new immune system (hematopoietic stem cell transplantation), using either autologous stem cell transplantation, or those from a matched donor (an allogeneic stem cell transplant). A presentation at the December 2007 American Society of Hematology (ASH) conference by Christian Geisler, chairman of the Nordic Lymphoma Group claimed that according to trial results, mantle cell lymphoma is potentially curable with very intensive chemo-immunotherapy followed by a stem cell transplant, when treated upon first presentation of the disease.

These results seem to be confirmed by a large trial of the European Mantle Cell Lymphoma Network indicating that induction regimens containing monoclonal antibodies and high dose ARA-C (Cytarabine) followed by ASCT should become the new standard of care of MCL patients up to approximately 65 years.

A study released in April 2013 showed that patients with previously untreated indolent lymphoma, bendamustine plus rituximab can be considered as a preferred first-line treatment approach to R-CHOP because of increased progression-free survival and fewer toxic effects.

There is no standard therapy for multicentric Castleman disease. Treatment modalities change based on HHV-8 status, so it is essential to determine HHV-8 status before beginning treatment. For HHV-8-associated MCD the following treatments have been used: rituximab, antiviral medications such as ganciclovir, and chemotherapy.

Treatment with the antiherpesvirus medication ganciclovir or the anti-CD20 B cell monoclonal antibody, rituximab, may markedly improve outcomes. These medications target and kill B cells via the B cell specific CD20 marker. Since B cells are required for the production of antibodies, the body's immune response is weakened whilst on treatment and the risk of further viral or bacterial infection is increased. Due to the uncommon nature of the condition there are not many large scale research studies from which standardized approaches to therapy may be drawn, and the extant case studies of individuals or small cohorts should be read with caution. As with many diseases, the patient's age, physical state and previous medical history with respect to infections may impact the disease progression and outcome.

Kaposi sarcoma is not curable, but it can often be treatable for many years. In KS associated with immunodeficiency or immunosuppression, treating the cause of the immune system dysfunction can slow or stop the progression of KS. In 40% or more of peoples with AIDS-associated Kaposi sarcoma, the Kaposi lesions will shrink upon first starting highly active antiretroviral therapy (HAART). However, in a certain percentage of such people, Kaposi sarcoma may again grow after a number of years on HAART, especially if HIV is not completely suppressed.

People with a few local lesions can often be treated with local measures such as radiation therapy or cryosurgery. Weak evidence suggests that antiretroviral therapy in combination with chemotherapy is more effective than either of those two therapies individually. Limited basic and clinical evidence suggest that topical beta-blockers, such as timolol, may induce regression of localized lesions in classic as well as HIV-associated Kaposi sarcoma. In general, surgery is not recommended, as Kaposi sarcoma can appear in wound edges. In general, more widespread disease, or disease affecting internal organs, is treated with systemic therapy with interferon alpha, liposomal anthracyclines (such as Doxil) or paclitaxel.

For HHV-8-negative MCD (idiopathic MCD), the following treatments have been used: corticosteroids, rituximab, monoclonal antibodies against IL-6 such as tocilizumab and siltuximab, and the immunomodulator thalidomide.

Prior to 1996 MCD carried a poor prognosis of about 2 years, due to autoimmune hemolytic anemia and non-Hodgkin's lymphoma which may arise as a result of proliferation of infected cells. The timing of diagnosis, with particular attention to the difficulty of determining the cause of B symptoms without a CT scan and lymph node biopsy, may have a significant impact on the prognosis and risk of death. Left untreated, MCD usually gets worse and becomes increasingly difficult and unresponsive to current treatment regimens.

Siltuximab prevents it from binding to the IL-6 receptor, was approved by the U.S. Food and Drug Administration for the treatment of multicentric Castleman disease on April 23, 2014. Preliminary data suggest that treatment siltuximab may achieve tumour and symptomatic response in 34% of patients with MCD.

Other treatments for multicentric Castleman disease include the following:

- Corticosteroids

- Chemotherapy

- Thalidomide

In November 2013, ibrutinib was approved by the US FDA for treating MCL.

Other targeted agents include the proteasome inhibitor bortezomib, mTOR inhibitors such as temsirolimus, and the P110δ inhibitor GS-1101.

Due to the high risk of recurrence and ensuing problems, close monitoring of dogs undergoing chemotherapy is important. The same is true for dogs that have entered remission and ceased treatment. Monitoring for disease and remission/recurrence is usually performed by palpation of peripheral lymph nodes. This procedure detects gross changes in peripheral lymph nodes. Some of the blood tests used in diagnosing lymphoma also offer greater objectivity and provide an earlier warning of an animal coming out of remission.

Complete cure is rare with lymphoma and treatment tends to be palliative, but long remission times are possible with chemotherapy. With effective protocols, average first remission times are 6 to 8 months. Second remissions are shorter and harder to accomplish. Average survival is 9 to 12 months. The most common treatment is a combination of cyclophosphamide, vincristine, prednisone, L-asparaginase, and doxorubicin. Other chemotherapy drugs such as chlorambucil, lomustine (CCNU), cytosine arabinoside, and mitoxantrone are sometimes used in the treatment of lymphoma by themselves or in substitution for other drugs. In most cases, appropriate treatment protocols cause few side effects, but white blood cell counts must be monitored.

Allogeneic and autologous stem cell transplantations (as is commonly done in humans) have recently been shown to be a possible treatment option for dogs. Most of the basic research on transplantation biology was generated in dogs. Current cure rates using stem cell therapy in dogs approximates that achieved in humans, 40-50%.

When cost is a factor, prednisone used alone can improve the symptoms dramatically, but it does not significantly affect the survival rate. The average survival times of dogs treated with prednisone and untreated dogs are both one to two months. Using prednisone alone can cause the cancer to become resistant to other chemotherapy agents, so it should only be used if more aggressive treatment is not an option.

Isotretinoin can be used to treat cutaneous lymphoma.

Treatment can occasionally consist of "watchful waiting" (e.g. in CLL) or symptomatic treatment (e.g. blood transfusions in MDS). The more aggressive forms of disease require treatment with chemotherapy, radiotherapy, immunotherapy and—in some cases—a bone marrow transplant. The use of rituximab has been established for the treatment of B-cell–derived hematologic malignancies, including follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL).

There is no proven or standard first-line chemotherapy that works for the majority of AITL patients. There are several clinical trials that offer treatment options that can fight the disease. Stem cell transplantation is the treatment of choice, with the allogeneic one being the preference because AITL tends to recur after autologous transplants.

If treatment has been successful ("complete" or "partial remission"), a person is generally followed up at regular intervals to detect recurrence and monitor for "secondary malignancy" (an uncommon side-effect of some chemotherapy and radiotherapy regimens—the appearance of another form of cancer). In the follow-up, which should be done at pre-determined regular intervals, general anamnesis is combined with complete blood count and determination of lactate dehydrogenase or thymidine kinase in serum.

One such development is in the delivery of doxorubicin. While it is an effective inducer of apoptosis, doxorubicin is quickly filtered out of the body. By loading a PEG-liposome with doxorubicin the circulation time and localization to tumors greatly increases. Cancerous tumors characteristically have extensive angiogenesis and leaky vasculatures, which causes the PEG-liposomes to naturally accumulate in the tumor. This also allows for patients to receive lower and fewer doses of the drug and experience fewer side effects. This is also being attempted with nanoparticles but has not been tested on FDCS. In 2008 COP plus (PEG)-liposomal doxorubicin went into a clinical trial for an FDCS patient to replace the CHOP regimen, and after 5 years the patient remains in CR.

Some patients have no symptoms, spontaneous remission, or a relapsing/remitting course, making it difficult to decide whether therapy is needed. In 2002, authors from Sapienza University of Rome stated on the basis of a comprehensive literature review that "clinical observation without treatment is advisable when possible."

Therapeutic options include surgery, radiation therapy, and chemotherapy. Surgery is used to remove single lymph nodes, central nervous system lesions, or localized cutaneous disease. In 2014, Dalia and colleagues wrote that for patients with extensive or systemic Rosai–Dorfman disease, "a standard of care has not been established" concerning radiotherapy and chemotherapy.

Blood tests to detect antibodies against KSHV have been developed and can be used to determine whether a person is at risk for transmitting infection to their sexual partner, or whether an organ is infected prior to transplantation. However, these tests are not available except as research tools, and, thus, there is little screening for persons at risk for becoming infected with KSHV, such as people following a transplant.

Treatment with chemotherapy has been used with some success, particularly using lomustine, prednisone, doxorubicin, and cyclophosphamide. Because of the rapid progression of this aggressive disease, the prognosis is very poor.

Newer cases are also starting to be treated by taxotere and gemcitabine. Taxotere is similar to Oncovin used in CHOP; it irreversibly binds beta tubulin halting formation of microtubules. Taxotere has an added benefit though; it also phosphorylates bcl-2 to halt the anti-apoptotic pathway. The dual effect of taxotere on integral cancer pathways makes it a more potent drug than Oncovin. Gemcitabene is a nucleoside analog and when incorporated into DNA during replication leads to apoptosis; the fluorine on the 2’ carbon atom stops other nucleosides from attaching. The most important part of this combination therapy, however, is the synergism between the drugs. While researchers are not entirely sure of the mechanism, there is evidence of synergistic effects of taxotere and gemcitabine when used in combination. This allows for decreased dosages of each single agent with an increased apoptotic response.

Chemotherapy is the mainstay of treatment for lymphoma in cats. Most of the drugs used in dogs are used in cats, but the most common protocol uses cyclophosphamide, vincristine, and prednisone. Gastrointestinal lymphoma has also commonly been treated with a combination of prednisolone and high dose pulse chlorambucil with success. The white blood cell count must be monitored. Remission and survival times are comparable to dogs. Lower stage lymphoma has a better prognosis. Multicentric lymphoma has a better response to treatment than the gastrointestinal form, but infection with FeLV worsens the prognosis.

About 75% of cats treated with chemotherapy for lymphoma go into remission. Unfortunately, after an initial remission, most cats experience a relapse, after which they have a median survival of 6 months. However, about one-third of cats treated with chemotherapy will survive more than 2 years after diagnosis; a small number of these cats may be cured of their disease. Untreated, most cats with lymphoma die within 4–6 weeks. Most cats tolerate their chemotherapy well, and fewer than 5% have severe side effects. Cats do not lose their fur from chemotherapy, though loss of whiskers is possible. Other side effects include low white blood cell count, vomiting, loss of appetite, diarrhea, or fatigue. These can typically be controlled well, and most cats have a good quality of life during treatment. If a cat relapses after attaining remission, the cat can be treated with different chemotherapy drugs to try for a second remission. The chances of a second remission are much lower than the chances of obtaining a first, and the second remission is often shorter than the first.

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.