Hodgkin Lymphoma

Hodgkin lymphoma (HL), aka Hodgkin's lymphoma or Hodgkin's disease is a type of lymphoma, a cancer originating in the lymphocytes.

Hodgkin lymphomas make up approximately 10% of lymphoma cases while non-Hodgkin lymphomas make up approximately 90% of cases.

Epidemiology

In 2020, worldwide:

0.4% of new cancer-related cases involved HL
0.2% of cancer-related deaths involved HL

Though it may be relatively rare, it was the most common cancer diagnosed in people aged 15–19 years.

Etiology

The etiology for HL is unknown, but various infectious agents such as Epstein-Barr virus and HIV have been shown to be related to higher incidence rates.

Additionally, there may be a genetic predisposition as about 1% of patients with HL have family history, with siblings having a 3- to 7-fold increased risk.

Epstein-Barr Virus (EBV)

Infection with EBV may be particularly important in HL pathogenesis
EBV proteins are positive in about 30% of classic HL patients

Pathogenesis

HL patient lymph nodes show scattering of Reed-Sternberg cells often mixed with reactive immune cells. Pathologic features may be associated with abnormal immune response from cytokine and chemokine expression by Reed-Sternberg cells.

Reed-Sternberg Cells

The neoplastic cell in classic HL
Often of B-cell origin
Consistently express CD30 and CD15 antigens

Types of HL

The two main types are nodular lymphocyte-predominant (NLPHL) and classic HL. NLPHL is less prevalent and has characteristic so-called "popcorn cells" that express CD20 antigen. Classic HL is more prevalent and has four subtypes:

Lymphocyte-Depleted

Rare
Often many pleomorphic Reed-Sternberg cells and few reactive lymphocytes
Often confused with diffuse large cell lymphoma

Mixed Cellularity

Common; most often associated with EBV infection and immunocompromised people
Many Reed-Sternberg cells mixed with many inflammatory cells

Lymphocyte-Rich

Rare
Often confused with predominant B-cell non-Hodgkin lymphoma
Most favourable prognosis

Nodular Sclerosing HL

Most common
Large tumour nodules with scattered Reed-Sternberg cells and background reactive lymphocytes
Varying presence of collagen fibrosis

Signs & Symptoms

Enlarged lymph nodes
B symptoms
- Fever without infection
- Night sweats
- Unintended weight loss (10% or more over 6 months)
Itchy skin
Fatigue
Loss of appetite
Chest symptoms (when chest lymph nodes are affected)
- Coughing
- Trouble breathing
- Breast bone pain

Treatment

Treatment for HL mainly consists of chemotherapy or radiation, and in some cases both. Those with early stage HL are effectively treated with radiation or chemotherapy while those in later stages tend to only use combination chemotherapy. Additional treatments may involve immunotherapy or stem cell transplant. Surgery is rarely used.

The main goal of treatment is to lower the risk of secondary conditions associated with HL such as secondary cancers and cardiac issues.

Prognosis

The 5-year survival rate (based on data from 2012–2018) for all stages combined was 89%.

Success of treatment has been identified to depend on the following adverse prognostic factors:

Mixed cellularity or lymphocyte-depleted type
Male sex
45 years of age or older
Advanced staging
B symptoms or bulky disease
Low red blood cell count, blood lymphocyte count, and blood albumin level
High erythrocyte sedimentation rate