Epstein–Barr virus-associated lymphoproliferative diseases
Epstein–Barr virus-associated lymphoproliferative diseases are a group of benign, premalignant, and malignant diseases of lymphoid cells, i.e. B cells, T cells, NK cells, and histiocytic-dendritic cells in which one or more of these cell types is infected with the Epstein–Barr virus (EBV). The virus may be responsible for the development and/or progression of these diseases. In addition to EBV-positive Hodgkin lymphomas, the World Health Organization (2016) includes the following lymphomas, when associated with EBV infection, in this group of diseases: Burkitt lymphoma; large B cell lymphoma, not otherwise specified; diffuse large B cell lymphoma associated with chronic inflammation; fibrin-associated diffuse large B cell lymphoma; primary effusion lymphoma; plasmablastic lymphoma; extranodal NK/T cell lymphoma, nasal type; peripheral T cell lymphoma, not otherwise specified; angioimmunoblastic T cell lymphoma; follicular T cell lymphoma; and systemic T cell lymphoma of childhood. WHO classification
The WHO classification, published in 2001 and updated in 2008, is based upon the foundations laid within the "revised European–American lymphoma classification" (REAL). This system groups lymphomas by cell type (i.e. the normal cell type that most resembles the tumor) and defining phenotypic, molecular, or cytogenetic characteristics. The five groups are shown in the table. Hodgkin lymphoma is considered separately within the WHO and preceding classifications, although it is recognized as being a tumor, albeit markedly abnormal, of lymphocytes of mature B cell lineage.Of the many forms of lymphoma, some are categorized as indolent (e.g. small lymphocytic lymphoma), compatible with a long life even without treatment, whereas other forms are aggressive (e.g.
This examination reveals histopathological features 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
Fluorescence in situ hybridization testing

Classification
According to the World Health Organization (WHO), lymphoma classification should reflect in which lymphocyte population the neoplasm arises. Thus, neoplasms that arise from precursor lymphoid cells are distinguished from those that arise from mature lymphoid cells. Most mature lymphoid neoplasms comprise the non-Hodgkin lymphomas. Historically, mature histiocytic and dendritic cell (HDC) neoplasms have been considered mature lymphoid neoplasms, since these often involve lymphoid tissue.Lymphoma can also spread to the central nervous system, often around the brain in the meninges, known as lymphomatous meningitis (LM). Hodgkin lymphoma
Hodgkin lymphoma accounts for about 15% of lymphomas. It differs from other forms of lymphomas in its prognosis and several pathological characteristics. A division into Hodgkin and non-Hodgkin lymphomas is used in several of the older classification systems. A Hodgkin lymphoma is marked by the presence of a type of cell called the Reed–Sternberg cell. Non-Hodgkin lymphomas
Non-Hodgkin lymphomas, which are defined as being all lymphomas except Hodgkin lymphoma, are more common than Hodgkin lymphoma. A wide variety of lymphomas are in this class, and the causes, the types of cells involved, and the prognoses vary by type. The number of cases per year of non-Hodgkin lymphoma increases with age. It is further divided into several subtypes.