Lymphoma presents with certain non-specific symptoms. If symptoms are persistent, lymphoma needs to be excluded medically.

• Lymphadenopathy^[2][4] or swelling of lymph nodes - It is the primary presentation in lymphoma.
• B symptoms (systemic symptoms) - Can be associated with both Hodgkin's lymphoma and non-Hodgkin's lymphoma. They consist of:
  • Fever^[2][4]
  • Night sweats^[2][4]
  • Weight loss^[2][4]
• Other Symptoms :
  • Loss of appetite or anorexia^[4]
  • Fatigue^[2][4]
  • Respiratory distress or dyspnoea^[4]
  • Itching^[2][4]

Lymphoma is definitively diagnosed by alymph node biopsy, meaning a partial or total excision of a lymph node that is then examined under the microscope.^[5] This examination reveals histopathologicalfeatures that may indicate lymphoma. After lymphoma is diagnosed, a variety of tests may be carried out to look for specific features characteristic of different types of lymphoma. These include:

• Immunophenotyping
• Flow cytometry
• FISH testing.

Several classification systems have existed for lymphoma. These systems use histological findings and other findings to divide lymphoma into different categories. The classification of lymphoma can affect treatment and prognosis. Classification systems generally classify lymphoma according to:

• Whether or not it is a Hodgkin lymphoma.
• Whether the cell that is replicating is a T cell or B cell.
• The site that the cell arises from.

Hodgkin's lymphoma

Hodgkin's lymphoma is one of the most well-known types of lymphoma,^{[citation needed]} and differs from other forms of lymphoma in itsprognosis and several pathologicalcharacteristics. A division into Hodgkin's and non-Hodgkin's lymphomas is used in several formal classification systems. A Hodgkin's lymphoma is marked by the presence of a type of cell called the Reed-Sternberg cell.^[6][7]

WHO classification

The current accepted definition is the WHO classification, published in 2001 and updated in 2008,^[8][9] is the latest classification of lymphoma and is based upon the foundations laid within the "Revised European-American Lymphoma classification" (REAL). This system attempts to group lymphomas by cell type (i.e. the normal cell type that most resembles the tumor) and definingphenotypic, molecular or cytogeneticcharacteristics. There are three large groups: the B cell, T cell, and natural killer cell tumors. Other less common groups, are also recognized. Hodgkin lymphoma, although considered separately within the World Health Organization (and preceding) classifications, is now recognized as being a tumor of, albeit markedly abnormal, lymphocytes of mature B cell lineage.

Working Formulation

The 1996 Working Formulation was a classification of non-Hodgkin lymphoma. It excluded the Hodgkin lymphomas and divided the remaining lymphomas into four grades (Low, Intermediate, High, and Miscellaneous) related to prognosis, with some further subdivisions based on the size and shape of affected cells. This purely histological classification included no information about cell surface markers, or genetics, and it made no distinction betweenT-cell lymphomas or B-cell lymphomas. It was widely accepted at the time of its publication but is now obsolete.^[10] It is still used by some cancer agencies for compilation of lymphoma statistics and historical rate comparisons.^{[citation needed]}

Other

• REAL. In the mid 1990s, the Revised European-American Lymphoma (REAL) Classification attempted to apply immunophenotypic and genetic features in identifying distinct clinicopathologic entities among all the lymphomas except Hodgkin's lymphoma.^[11]
• ICD-O (codes 9590-9999, details at [2])
• ICD-10 (codes C81-C96, details at [3])

Subtypes

There are many forms of lymphoma. Some forms of lymphoma are categorized as indolent (e.g. small lymphocytic lymphoma), compatible with a long life even without treatment, whereas other forms are aggressive (e.g. Burkitt's lymphoma), causing rapid deterioration and death. However, most of the aggressive lymphomas respond well to treatment and are curable. The prognosistherefore depends on the correct diagnosis and classification of the disease, which is established after examination of a biopsy by apathologist (usually a hematopathologist).^[12]

Prognosis and treatment is different for HL and between all the different forms of NHL,^[20]and also depends on the grade of tumour, referring to how quickly a cancer replicates. Paradoxically, high-grade lymphomas are more readily treated and have better prognoses^{[citation needed]}. A well-known example of a high-grade tumour is that ofBurkitt's lymphoma, which is a high-grade tumour that has been known to double within days, but is readily treated.

Low-grade lymphomas

Many low-grade lymphomas remain indolent for many years. In these lymphomas,metastases are very likely. For this reason, treatment of the non-symptomatic patient is often avoided. In these forms of lymphoma^[which?], watchful waiting is often the initial course of action. This is carried out because the harms and risks of treatment outweigh the benefits.^[21] 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 painfullymphadenopathy. Patients with these types of lymphoma can live near-normal lifespans, but the disease is incurable.

High-grade lymphomas

Treatment of some other, more aggressive, forms of lymphoma^[which?] can result in a cure in the majority of cases, but the prognosis for patients with a poor response to therapy is worse.^[22] Treatment for these types of lymphoma typically consists of aggressive chemotherapy, including the CHOP or R-CHOP regimen.

Hodgkin lymphoma typically is treated with radiotherapy alone, as long as it is localized.^[23] Advanced Hodgkin disease requires systemic chemotherapy, sometimes combined with radiotherapy.^[24]Chemotherapy used includes the ABVDregimen.