The factors of poor prognosis for patients with thyroid lymphoma are advanced stage of the tumor, large size (>10 cm) as well as spreading to mediastinum. The overall survival for primary thyroid lymphoma is 50% to 70%, ranging from 80% in stage IE to less than 36% in stage IIE and IVE in 5 years.

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.

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.

Primary cerebral lymphoma (or "primary central nervous system lymphoma") is a form of NHL. It is very rare in immunocompetent people, with an incidence of 5–30 cases per million person-years. However the incidence in immunocompromised individuals is greatly increased, up to 100 per million person-years.

Primary cerebral lymphoma is strongly associated with Epstein–Barr virus (EBV). The presence of EBV DNA in cerebrospinal fluid is highly suggestive of primary cerebral lymphoma.

Treatment of AIDS patients with antiretroviral drugs reduces the incidence of primary cerebral lymphoma.

Of all cancers involving the same class of blood cell (lymphoproliferative disorders), 22% of cases are follicular lymphomas.

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.

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.

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

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

The incidence of Hodgkin's disease in the general population is about 10–30 per million person-years. This increases to 170 per million person-years in HIV positive patients.

It is rare for the disease to appear before age 20, and it appears to be noticeably more common in males than females, especially over the age of 50, where the incidence of the disease (the risk per person in the population) does increase. The average age of onset is between 45 and 55 years of age for patients with patch and plaque disease only, but is over 60 for patients who present with tumours, erythroderma (red skin) or a leukemic form (the Sézary syndrome). The incidence of mycosis fungoides was seen to be increasing till the year 2000 in the United States, thought to be due to improvements in diagnostics. However, the reported incidence of the disease has since then remained constant, suggesting another unknown reason for the jump seen before 2000.

Median survival is around 10 years, but the range is wide, from less than one year, to more than 20 years. Some patients may never need treatment. The overall survival rate at five years is 72–77%. Recent advances and addition of Rituximab, improved median survival. Recent reports for the period 1986 and 2012 estimates median survival of over 20 years.

Lymph node abnormalities and organ dysfunction in Castleman disease are caused by excessive secretion of cytokines. IL-6 is the most commonly elevated cytokine, but some affected people may have normal IL-6 levels and present with non-iron-deficient microcytic anemia.

The release of these cytokines is caused by infection with Human herpesvirus 8 in HHV-8-associated MCD. The cause of the release of cytokines in idiopathic MCD has been hypothesized to be caused by either a somatic mutation, a germline genetic mutation, or a non-HHV-8-virus.

In the unicentric form of the disease, surgical resection is often curative, and the prognosis is excellent.

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.

As other thyroid lesions, thyroid lymphoma affects predominantly females over 70 years of age with a history of Hashimoto's thyroiditis. Thus, Hashimoto's thyroiditis is considering as risk factor for thyroid lymphoma development.

The thyroid lymphoma manifests as rapidly enlarging neck mass causing respiratory difficulty. On physical examination, patients usually exhibit a firm thyroid and lymphadenopathy.

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 cause of mycosis fungoides is unknown, but it is not believed to be hereditary or genetic in the vast majority of cases. One incident has been reported of a possible genetic link. It is not contagious.

The disease is an unusual expression of CD4 T cells, a part of the immune system. These T cells are skin-associated, meaning that they biochemically and biologically are most related to the skin, in a dynamic manner. Mycosis fungoides is the most common type of cutaneous T-cell lymphoma (CTCL), but there are many other types of CTCL that have nothing to do with mycosis fungoides and these disorders are treated differently.

Risk factors for gastric lymphoma include the following:

- "Helicobacter pylori"

- Long-term immunosuppressant drug therapy

- HIV infection

Lymphatic disease is a class of disorders which directly affect the components of the lymphatic system.

Examples include Castleman's disease and lymphedema.

Diseases and disorder

Hodgkin's Disease/Hodgkin's Lymphoma

This is a type of cancer of the lymphatic system. It can start almost anywhere in the body. It is believed to be caused by HIV, Epstein-Barr Syndrome, age and family history. Symptoms include weight loss, fever, swollen lymph nodes, night sweats, itchy skin, fatigue, chest pain, coughing or trouble swallowing.

Non-Hodgkin's Lymphoma

Lymphoma is a usually malignant cancer. It is caused by the body producing too many abnormal white blood cells. It is not the same as Hodgkin's Disease. Symptoms usually include painless, enlarged lymph node or nodes in the neck, weakness, fever, weight loss, and anemia.

Lymphadenitis is an infection of the lymph nodes usually caused by a virus, bacteria or fungi. Symptoms include redness or swelling around the lymph node.

Lymphangitis

Lymphangitis is an inflammation of the lymph vessels. Symptoms usually include swelling, redness, warmth, pain or red streaking around the affected area.

Lymphedema

Lymphedema is the chronic pooling of lymph fluid in the tissue. It usually starts in the feet or lower legs. It's also a side-effect of some surgical procedures.

Lymphocytosis

Lymphocytosis is a high lymphocyte count. It can be caused by an infection, blood cancer, lymphoma, or autoimmune disorders that are accompanied by chronic swelling.

LCH usually affects children between 1 and 15 years old, with a peak incidence between 5 and 10 years of age. Among children under the age of 10, yearly incidence is thought to be 1 in 200,000; and in adults even rarer, in about 1 in 560,000. It has been reported in elderly but is vanishingly rare. It is most prevalent in Caucasians, and affects males twice as often as females. In other populations too the prevalence in males is slightly more than in females.

LCH is usually a sporadic and non-hereditary condition but familial clustering has been noted in limited number of cases. Hashimoto-Pritzker disease is a congenital self-healing variant of Hand-Schüller-Christian disease.

Gray zone lymphoma, often presenting as large tumors in the mediastinum, is a type of lymphoma that is characterized by having cellular features of both classic Hodgkin's lymphomas (cHL) and large B-cell lymphomas.

Excellent for single-focus disease. With multi-focal disease 60% have a chronic course, 30% achieve remission and mortality is up to 10%.

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

There are numerous kinds of lymphomas involving B cells. The most commonly used classification system is the WHO classification, a convergence of more than one, older classification systems.