Classification With a few exceptions,<unk> s are of B cell origin. They are classified based on pathological and cytological features. Subtypes include follicular lymphoma, marginal zone lymphoma, lymphoplasmacytic lymphoma, chronic lymphocytic leukemia, and hairy cell leukemia. Follicular lymphoma Follicular lymphoma (FL) is a lymphoproliferative disorder generally associated with an<unk>  course. It originates from follicular center B cells. About 85% of cases show t(14;18)(q32;q21) chromosomal translocation, which causes the overexpression of the anti-apoptotic protein Bcl-2. FL is characterized by diffuse lymphadenopathy, bone marrow involvement, and splenomegaly. Involvement of non-lymphatic areas is less common. Cytopenias are relatively common, but constitutional symptoms such as fever, night sweats, and weight loss are rare in the absence of transformation to diffuse large B cell lymphoma. The five-year survival rate in the United States is 88.4%. FL is the most prevalent form of<unk> , accounting for 70% of<unk>  cases and 20–30% of all non-Hodgkin lymphoma cases, with a yearly incidence of 1.6 to 3.1 per 100,000. It is most frequently diagnosed among people in their 50s and 60s, and is more common among white populations than black or Asian populations. Cutaneous T-cell lymphoma Cutaneous T-cell lymphoma (very high magnification) Unlike most NHL subtypes, cutaneous T-cell lymphoma (CTCL) is derived from T cells. Mycosis fungoides, which attacks the skin, is the most common form of CTCL. When cancer cells infiltrate and accumulate in the blood, it is known as Sézary syndrome. Diagnosis of CTCL is often delayed due to the presence of multiple clinical presentations and the lack of definitive diagnostic criteria. Patients can be misdiagnosed with a variety of benign skin conditions, including dermatitis, eczema, parapsoriasis, psoriasis, and adverse drug reactions. It takes six years on average from disease onset to confirmation of diagnosis. Marginal zone lymphoma Marginal zone lymphoma (MZL) is a heterogeneous group of<unk>  B cell lymphomas that arise from the marginal zone of lymphoid tissues. It accounts for 5–10% of all NHL cases, with an annual incidence of 0.4 to 1.0 per 100,000 in Western countries. The median age at diagnosis is 67 years, and the disease is slightly more common in women than in men. The World Health Organization categorizes MZL into three subtypes: nodal, extranodal, and splenic. Nodal MZL occurs within the lymph nodes. Extranodal MZL occurs in areas outside the lymph nodes, with the stomach being the most common site. Splenic MZL develops in the spleen and may spread to the blood. Chronic lymphocytic leukemia and small cell lymphocytic lymphoma Chronic lymphocytic leukemia (CLL) and small cell lymphocytic lymphoma (SLL) are different manifestations of the same disease and are managed in the same way. When the abnormal lymphocytes are located mostly in the lymph nodes, it is referred to as SLL; when the abnormal lymphocytes are mostly in the blood and bone marrow, it is called CLL. CLL is the most common leukemia in Western countries, but it is very rare in East Asia. The median age at diagnosis is 72 years. Staging Staging describes the extent of<unk> , whether it has spread and, if so, how far it has spread. The disease can spread through tissue, the lymphatic system and the blood. The Lugano modification of the Ann Arbor system is used to stage lymphoma. Stage I: The lymphoma is in one lymph node or one group of lymph nodes; or, in rare cases, in one organ of the lymphatic system such as Waldeyer’s ring, the thymus, or the spleen; or in one site outside the lymphatic system (IE). Stage II: The lymphoma is in two or more groups of lymph nodes; or in one nearby area outside the lymphatic system, with or without involvement of other lymph nodes (IIE). In either case, the lymphoma sites are on the same side of the diaphragm. In Stage II, "bulky disease" means tumor mass larger than a certain size; the threshold depends on the type of lymphoma. Stage III: The lymphoma is on both sides of the diaphragm, either in lymph nodes both above and below the diaphragm, or in lymph nodes above the diaphragm and in the spleen. Stage IV: The lymphoma is in one or more organs beyond the lymphatic system, such as the liver, lungs, bone marrow, or cerebrospinal fluid. A patient's stage may be determined through blood tests, bone marrow biopsy, chest X-rays, computed tomography (CT) scans, positron emission tomography (PET) scans, and magnetic resonance imaging (MRI).
Indolent lymphoma
Aggressive lymphoma
Gray zone lymphoma
Follicular lymphoma
Nodular lymphocyte predominant Hodgkin lymphoma
AIDS-related lymphoma
Mixed-cell lymphoma
Hodgkin lymphoma