About Hodgkin lymphoma

Hodgkin lymphoma (also known as Hodgkin's disease) is a blood cancer that develops in lymphocytes, a type of white blood cell. These blood cells are in the lymphatic system, a network of vessels, nodes and organs that filter waste and toxins and help fight infection.

The main types of lymphocytes are T-cells and B-cells, which are white blood cells made in bone marrow. B-cells remain in the bone marrow to mature, while T-cells mature in the thymus, a small organ nestled between the lungs. B-cells are far more likely than T-cells to mutate and cause a liquid cancer such as Hodgkin lymphoma, non-Hodgkin lymphoma or leukemia.

The main difference between Hodgkin lymphoma and non-Hodgkin lymphoma is the presence or absence of oversized B-cells called Reed-Sternberg cells. These cells are usually detected during a biopsy and indicate the presence of Hodgkin lymphoma.

The American Cancer Society estimates that 8,830 new cases of Hodgkin lymphoma will be diagnosed in the United States in 2021, with 4,830 in males and 4,000 in females.

Cancer research has not identified the cause of this type of lymphoma. Risk factors that may increase the chances of developing the disease include:

• Epstein-Barr virus (EBV), known for causing “mono” (mononucleosis) in young adults
• Compromised immune system, such as from HIV/AIDS or immunosuppressants to prevent organ transplant rejection
• A family history of the disease

Adults in their 20s and early 30s and those over age 55 are at an increased risk for developing Hodgkin lymphoma. It is most common in early adulthood, aged 20 and older.

Men have a slightly greater chance of developing the disease than women. Hodgkin lymphoma is most common in North America and northern Europe. It also is more common in individuals with a higher socioeconomic background.

There are two types of Hodgkin lymphoma. About 95 percent of all cases are classic Hodgkin lymphoma (or classical). This cancer type is divided into four subtypes:

• Nodular sclerosis, which often occurs in children and young adults, especially young females, and is usually found in the chest and/or neck
• Mixed cellularity, more common in older adults and is often found in the abdomen
• Lymphocyte-rich, most often diagnosed in men
• Lymphocyte-depleted, most often diagnosed in older adults or people with HIV

A second, less common type of Hodgkin lymphoma is nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL), most often diagnosed in middle-aged adults. It is characterized by so-called popcorn cells, lobular versions of Reed-Sternberg cells that resemble popcorn. Some patients with NLPHL go on to develop diffuse large B-cell lymphoma, a fast-growing type of non-Hodgkin lymphoma.

Hodgkin lymphoma symptoms share many characteristics with other illnesses, such as a cold or flu. During the early stages of Hodgkin lymphoma, cancer cells may not cause any symptoms.

An early sign of Hodgkin lymphoma may be swelling in one or more lymph nodes, usually in the neck. When the concentration of white blood cells increases as part of the body's immune system response to virus or infection, the lymph nodes can become swollen. In some cases, the swelling is caused by another condition, like cancer.

Common symptoms of Hodgkin lymphoma include:

• Enlarged lymph nodes in the neck, armpit or groin
• Intermittent fevers
• Drenching night sweats
• Fatigue, or feeling tired all the time
• Unexplained weight loss
• Persistent cough
• Shortness of breath
• Chest discomfort
• Decreased appetite
• Abdominal pain or swelling
• Feeling of fullness
• Rash or itching

Tools and procedures for diagnosing Hodgkin lymphoma may include:

• Blood tests
• Biopsy, either of bone marrow or from a lymph node
• Flow cytometry test, which determines the relative growth rate of a tumor and the amount of DNA in it
• Computed tomography scan (CT scan)
• Positron emission tomography scan (PET scan)
• Pulmonary function test

According to the American Cancer Society, the five-year survival rate for Hodgkin lymphoma ranges from 78 percent for cancer that has spread to distant parts of the body to 92 percent for cancer that has not spread outside the lymph system. Treatment options for Hodgkin lymphoma may include:

• A chemotherapy regimen
• Stem cell transplantation
• Radiation therapy
• Immunotherapy