Hodgkin Lymphoma Hodgkin Lymphoma (HL) is a type of lymphoma, which is a cancer originating in the lymphatic system. It is characterized by the presence of Reed-Sternberg cells, large abnormal cells typically derived from B lymphocytes. HL accounts for about 10% of all lymphomas and is distinguished from other types by its unique clinical and pathological features. Types of Hodgkin Lymphoma: HL is classified into two main types: 1. Classical Hodgkin Lymphoma (cHL): This is the most common form, accounting for about 95% of cases. cHL is further subdivided into four subtypes based on the appearance of the cells under a microscope and the pattern of lymph node involvement: o Nodular sclerosis Hodgkin lymphoma (NSHL): The most common subtype, characterized by fibrous bands in the lymph nodes. o Mixed cellularity Hodgkin lymphoma (MCHL): Contains a mix of different cell types and is more common in older adults. o Lymphocyte-rich Hodgkin lymphoma (LRHL): Has a higher number of normal lymphocytes. o Lymphocyte-depleted Hodgkin lymphoma (LDHL): The rarest subtype, usually seen in older adults or those with HIV. 2. Nodular Lymphocyte-Predominant Hodgkin Lymphoma (NLPHL): A rarer form that is often slow-growing and differs significantly from cHL in its cellular makeup and behavior. Pathophysiology: HL begins when B lymphocytes, a type of white blood cell, develop mutations that cause them to grow and divide uncontrollably. The abnormal Reed-Sternberg cells in HL are identifiable under a microscope and are key to the diagnosis. These cells release cytokines, which cause an inflammatory response, attracting normal immune cells to the affected lymph nodes and contributing to the disease's characteristic symptoms. Clinical Presentation: Patients with HL typically present with:  Painless Lymphadenopathy: Swollen, painless lymph nodes, commonly in the neck, underarm, or groin.  B Symptoms: These include fever, night sweats, and unexplained weight loss. These symptoms indicate a more advanced disease.  Fatigue: Generalized fatigue is common.  Itching and skin rashes: Sometimes patients experience pruritus (itching).  Alcohol-induced pain: Rarely, some patients experience pain in affected lymph nodes after alcohol consumption. Diagnosis: The diagnosis of HL is confirmed through a lymph node biopsy, where the presence of Reed-Sternberg cells is identified. Additional tests, such as imaging (CT, PET scans) and bone marrow biopsy, are used to stage the disease and assess its spread. Staging: HL is staged based on the Ann Arbor system, which considers the number of lymph node regions involved, whether the disease has spread beyond the lymph nodes, and the presence of B symptoms. Stages range from I (localized) to IV (widespread). Treatment: Treatment typically involves a combination of chemotherapy and radiation therapy. The specific regimen depends on the stage and subtype of HL, as well as patient factors like age and overall health. Common chemotherapy protocols include ABVD (Adriamycin, Bleomycin, Vinblastine, and Dacarbazine) and BEACOPP. For early-stage disease, radiation may be used alone or in combination with chemotherapy. In cases of relapsed or refractory HL, more intensive therapies, such as stem cell transplantation or newer targeted therapies (e.g., brentuximab vedotin, checkpoint inhibitors), may be considered. Prognosis: The prognosis for HL is generally favorable, especially in younger patients and those diagnosed at an early stage. The 5-year survival rate for HL is around 86%, with better outcomes seen in patients with early-stage disease. Advances in treatment have significantly improved survival rates over the past few decades.