Definition Angioimmunoblastic T-cell lymphoma (AITL) is a systemic lymphoproliferative disorder characterized by generalized lymphadenopathy, hepatosplenomegaly, constitutional symptoms, rash, anemia, and polyclonal hypergammaglobulinemia. Histologically, the normal architecture of the lymph node is effaced by a polymorphic cellular infiltrate composed of lymphocytes,…
Definition The category of the peripheral T-cell lymphoma, unspecified, introduced in the Revised European-American Lymphoma classification in 1994, was renamed peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS) in the 2008 edition of the World Health Organization (WHO) classification, an…
Definition Hepatosplenic T-cell lymphoma (HSTL) is an aggressive subtype of extranodal lymphoma characterized by a hepatosplenic presentation without lymphadenopathy and a poor outcome. The neoplasm results from a proliferation of non-activated cytotoxic T cells, usually monomorphic and medium-sized, that exhibit…
Definition Adult T-cell leukemia/lymphoma (ATLL) is a mature T-cell neoplasm pathogenetically linked to human T-lymphotropic virus 1 (HTLV-1; also called human T-cell leukemia virus ). This is the first retrovirus proved to cause a human neoplasm. The disease is derived…
Definition T-cell prolymphocytic leukemia (T-PLL) is an aggressive disease characterized by a proliferation of small to medium-sized lymphocytes with a postthymic phenotype usually involving blood, bone marrow, lymph nodes, spleen, and skin. This leukemia was first described by Catovsky and…
History and Classification The first detailed studies of what is now recognized as T-cell large granular lymphocytic leukemia (T-LGL) were published in the 1970s and early 1980s. These manuscripts described a disorder associated with neutropenia or anemia that was associated…
Epstein-Barr virus (EBV) is a ubiquitous herpesvirus with tropism for B cells. More than 90% of humans are infected with EBV, and the infection persists for life. Usually primary infection is asymptomatic and occurs early in life, and when symptomatic…
The spectrum of virally associated B-cell lymphoproliferative diseases is broad, ranging from reactive lymphadenitis to lymphomas. Often the reactive processes can be diagnostically challenging and mimic lymphomas due to a combination of direct viral effects and indirect ones mediated by…
Definition Classical Hodgkin's lymphoma (CHL) is a clonal, malignant lymphoproliferation originating from germinal-center B cells. In contrast to most other lymphomas, the malignant cells usually represent only a small minority (0.1% to 2%) of the total cellular population of involved…
Definition The World Health Organization (WHO) recognizes nodular lymphocyte–predominant Hodgkin's lymphoma (NLPHL) as a separate entity distinct from classical Hodgkin's lymphoma (CHL) in the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. This reflects the fact that there are…