DESCRIPTION

• Historical background:
  • Described first in 1832 by Thomas Hodgkin who noted differences in patients from tuberculosis and syphilis
  • Carl Sternberg (1898) and Dorothy Reed (1902) independently identified the hallmark Reed-Sternberg (RS) cells—the microscopic hallmarks of Hodgkin disease.
  • Initially treated with herbs, surgery, and arsenic in the 19th century; HL showed sensitivity to X-rays in the beginning of the 20th century. Chemotherapy is instituted as first-line treatment in the early 1970s.
• Subtypes:
  • Classical HL (cHL)—95% of cases; includes nodular sclerosing 70%, mixed cellularity 20–25%, lymphocyte rich 5% and lymphocyte depleted <5%
  • Nodular lymphocyte predominant HL (NLPHL)—5% of cases

EPIDEMIOLOGY

• Incidence: 2 to 3 per 100,000 per year
• 11% of all lymphoid malignancies
• Bimodal age distribution peaks at 20 to 40 years and around 55 years, typically, diagnosed at median age of 39 years
• 1.3:1 male-to-female ratio

ETIOLOGY AND PATHOPHYSIOLOGY

• cHL is a B-cell lymphoma of germinal center origin that has lost its B-cell phenotype.
• RS cells have clonal rearrangements of immunoglobulin genes resulting in nonfunctional immunoglobulins and expression of apoptosis through oncogenic events.
• NLPHL lacks typical RS cells but has lymphocytic and histiocytic cells, characterized by larger cells with folded multilobulated nuclei (“popcorn cells” or LP cells)
• Genome-wide association studies identified 19p13.3 at intron 2 of TCF3.

RISK FACTORS

• HIV: increased risk of HL in patients who are HIV positive
• Epstein-Barr virus (EBV): detected in nearly 45% of HL cases
• Genetic predisposition: significantly in identical twins

GENERAL PREVENTION

Avoid exposure to chemicals such as pesticides, herbicides, and benzene.

COMMONLY ASSOCIATED CONDITIONS

HIV infection, geography, socioeconomic factors and family history