HL

HL is the abbreviation commonly used for Hodgkin lymphoma, a malignant lymphoma arising from lymphocytes, most often B cells, and characterized by the presence of Reed-Sternberg cells in affected tissues. It typically presents as a painless enlargement of lymph nodes, often in the neck or armpit. B symptoms such as fever, night sweats, and weight loss may occur. Mediastinal involvement is relatively common in younger patients.

Pathology and classification: Reed-Sternberg cells are large abnormal B cells that express CD15 and CD30 and usually lack CD45. Hodgkin lymphoma is divided into subtypes, most notably nodular sclerosis (the most common, especially in young adults), mixed cellularity, lymphocyte-rich, and lymphocyte-depleted, each with distinct clinical features.

Diagnosis and staging: diagnosis rests on an excisional lymph node biopsy. Imaging, typically PET-CT, is used to stage the disease and guide treatment. Bone marrow biopsy is not always required. Staging is I through IV, based on the number and location of affected regions and systemic involvement.

Treatment and prognosis: early-stage disease often uses chemotherapy (commonly ABVD) with or without involved-site radiotherapy; advanced-stage disease uses systemic chemotherapy, with regimens tailored to risk. Relapsed or refractory disease may be treated with salvage chemotherapy followed by autologous stem cell transplantation; targeted therapies such as brentuximab vedotin or PD-1 inhibitors are used in some relapsed cases. Overall prognosis is favorable, with high cure rates in many patients, particularly for early-stage disease. Hodgkin lymphoma was first described by Thomas Hodgkin in 1832.

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