Non-Hodgkin lymphoma (NHL) is a neoplasm of the lymphoid tissues originating from B cell precursors, mature B cells, T cell precursors, and mature T cells.
Non-Hodgkin lymphoma comprises various subtypes, each with different epidemiologies, etiologies, immunophenotypic, genetic, clinical features, and response to therapy. It can be divided into two groups, 'indolent' and 'aggressive,' based on the disease's prognosis.
The most common mature B cell neoplasms are Follicular lymphoma, Burkitt lymphoma, diffuse large B cell lymphoma, Mantle cell lymphoma, marginal zone lymphoma, primary CNS lymphoma. The most common mature T cell lymphomas are Adult T cell lymphoma, Mycosis fungoides.
The natural history of these tumors shows significant variation. Indolent lymphomas present with waxing and waning lymphadenopathy for many years, whereas aggressive lymphomas have specific B symptoms such as weight loss, night sweats, fever and can result in deaths within a few weeks if untreated. Lymphomas that usually have indolent presentations include follicular lymphoma, chronic lymphocytic leukemia/small lymphocytic lymphoma, and splenic marginal zone lymphoma. Aggressive lymphomas include diffuse large B cell lymphoma, Burkitt lymphoma, precursor B and T cell lymphoblastic leukemia/lymphoma, and adult T cell leukemia/lymphoma, and certain other peripheral T cell lymphomas.
Up to two-thirds of patients present with peripheral lymphadenopathy. Rashes on the skin, increased hypersensitivity reactions to insect bites, generalized fatigue, pruritus, malaise, fever of unknown origin, ascites, and effusions are less common presenting features. Approximately half of the patients develop the extranodal disease (secondary extranodal disease) during the course of their disease, while between 10 and 35 percent of patients have primary extranodal lymphoma at diagnosis. Primary gastrointestinal (GI) tract lymphoma may present with nausea and vomiting, aversion to food, weight loss, fullness of abdomen, early satiety, visceral obstruction related symptoms. Patients may even present with features of acute perforation and gastrointestinal bleeding, and at times with features of malabsorption syndrome. Primary central nervous system (CNS) lymphoma may present with headaches, spinal cord compression features, lethargy, focal neurologic deficits, seizures, and paralysis.