non-Hodgkin lymphoma

non-Hodgkin lymphoma
Name	non-Hodgkin lymphoma
Synonyms	NHL
Field	Hematology, Oncology
Symptoms	Enlarged lymph nodes, fever, night sweats, weight loss
Complications	Superior vena cava syndrome, Tumor lysis syndrome
Causes	Often unknown; associated with Epstein–Barr virus, Helicobacter pylori, Human T-lymphotropic virus 1
Risks	Immunodeficiency, Autoimmune diseases, certain Chemical substances
Diagnosis	Lymph node biopsy, Immunophenotyping, Computed tomography
Treatment	Chemotherapy, Radiation therapy, Immunotherapy, Stem cell transplantation
Prognosis	Varies widely by subtype
Frequency	~4% of Cancer in the United States
Deaths	~20,000 annually in the United States

non-Hodgkin lymphoma is a diverse group of Blood cancers originating in the Lymphocytes. It encompasses over 60 distinct subtypes, which are broadly categorized by their cell of origin—either B cells or T cells—and their clinical behavior. The disease is distinguished from Hodgkin lymphoma by the absence of Reed–Sternberg cells. Management and prognosis vary dramatically depending on the specific pathological diagnosis.

Classification and subtypes

The modern classification of these malignancies is primarily based on the World Health Organization's system, which integrates morphological, immunophenotypic, genetic, and clinical features. Major categories include B-cell lymphomas, such as Diffuse large B-cell lymphoma and Follicular lymphoma, and the less common T-cell lymphomas, like Peripheral T-cell lymphoma and Anaplastic large cell lymphoma. Further stratification considers the lymphoma's aggressiveness, dividing them into Indolent lymphomas, which grow slowly, and Aggressive lymphomas. Specific entities are linked to viral infections, such as Primary effusion lymphoma associated with Kaposi's sarcoma-associated herpesvirus.

Signs and symptoms

Common presenting features include painless enlargement of Lymph nodes in the Neck, Axilla, or Groin. Systemic "B symptoms" often signify more advanced disease and include unexplained Fever, drenching Night sweats, and significant Weight loss. Symptoms can also arise from extranodal involvement, such as Abdominal pain from Spleen or Gastrointestinal tract infiltration, Cough from mediastinal masses, or Neurological disorders from Central nervous system spread. Pruritus and Fatigue are also frequently reported.

Causes and risk factors

While the exact cause is often unidentified, several infectious agents, immune disorders, and environmental exposures are established risk factors. Key viral associations include Epstein–Barr virus with Burkitt lymphoma and Post-transplant lymphoproliferative disorder, and Human T-lymphotropic virus 1 with Adult T-cell leukemia/lymphoma. Bacterial infection with Helicobacter pylori is causative for Gastric MALT lymphoma. Other significant risks include congenital or acquired Immunodeficiency, such as in HIV/AIDS or following Organ transplantation, and Autoimmune diseases like Sjögren syndrome. Exposure to certain Chemical substances, including Herbicides and Insecticides, and prior treatment with Chemotherapy or Radiation therapy are also implicated.

Diagnosis

Definitive diagnosis requires a Lymph node biopsy or biopsy of other involved tissue for histopathological examination. Flow cytometry and Immunohistochemistry are used for Immunophenotyping to determine the lineage and subtype. Cytogenetics and Fluorescence in situ hybridization may detect characteristic genetic translocations, such as the MYC translocation in Burkitt lymphoma. Staging involves Computed tomography of the Chest, Abdomen, and Pelvis, and often Positron emission tomography. A Bone marrow biopsy is typically performed to assess for Bone marrow involvement.

Treatment

Therapeutic strategies are highly subtype-specific and depend on the stage and patient's Performance status. For many aggressive B-cell lymphomas, the cornerstone is Chemotherapy with the CHOP regimen, often combined with the Monoclonal antibody Rituximab (R-CHOP). Radiation therapy may be used for localized disease. For indolent lymphomas, initial management may involve Watchful waiting, with treatments like Bendamustine plus Rituximab deployed upon progression. Stem cell transplantation, either autologous or allogeneic, is considered for relapsed or refractory cases. Novel agents include Chimeric antigen receptor T-cell therapies like Axicabtagene ciloleucel and Tisagenlecleucel.

Prognosis and epidemiology

It represents approximately 4% of all Cancer in the United States, with an estimated 80,000 new cases annually. Incidence increases with age and is slightly higher in Men than Women. Prognosis is extremely heterogeneous; the five-year Relative survival rate for all subtypes is around 73%, but this ranges from over 90% for some indolent forms to under 60% for certain aggressive or refractory types. The International Prognostic Index is a widely used tool to predict outcomes based on factors like age, Lactate dehydrogenase level, and disease stage. Research efforts by organizations like the National Cancer Institute and the American Society of Hematology continue to refine classifications and therapies.

Category:Lymphoma Category:Hematology Category:Types of cancer