Hodgkin lymphoma

Hodgkin’s lymphoma is derived from a profoundly defective B cell, with the pathobiology, histology, and clinical features being both characteristic and distinct from non-Hodgkin’s lymphomas. Its cause is unknown. Incidence is about 3 per 100 000 per year in Western countries with a bimodal age distribution meaning that it is one of the commoner lymphomas of young people. Most cases are highly responsive to combination chemotherapy, with many patients being cured of their disease. Patients with Hodgkin’s lymphoma may present with lymphadenopathy, a mediastinal (or other) mass, and systemic symptoms including weight loss, fever, and night sweats (B-symptoms). Workup requires staging with positron emission tomography (PET)-CT imaging, and biopsy. Classical Hodgkin’s lymphoma is defined by the presence of the binucleate Reed–Sternberg cell in an appropriate inflammatory histological context. These cells have a characteristic immunohistochemical phenotype, showing CD15 and CD30 positivity, but being immunonegative for classical B-cell markers such as CD20. Additional histological subtypes have been defined, with the most clinically significant being lymphocyte-predominant Hodgkin’s lymphoma. Patients with localized disease may be treated with chemotherapy with or without radiotherapy. Those with more advanced-stage disease require combination chemotherapy, with radiotherapy to sites of initial bulk disease. While relapse is uncommon in patients with early-stage disease, some 20% of patients with advanced-stage disease may need ‘salvage’ chemotherapy regimens for relapsed disease, when the aim is to attain PET negativity before embarking on high-dose therapy with stem cell rescue. Since many patients have a good outcome, it is essential to minimize the long-term sequelae of treatment. Risk stratification is a major focus of clinical trials in this area to determine optimal treatment strategies.