Lymphoma, or in common parlance, blood cancers develop from lymphocytes, a type of white blood cells found in the immune system in the body. Like the circulatory system of blood, the lymphatic system that carries lymph fluid to fight infections runs throughout the body. Usually, when mutant lymphocytes divide abnormally, multiply more rapidly and live longer than normal lymphocytes, cancer develops. Lymphoma commonly occurs in the upper parts of the body like armpits, neck, or chest.
Spreading through the lymph vessels and lymph nodes, this cancer can invade the bloodstream and affect the liver, lungs, bone marrow, the digestive tract, groin, or the spleen too. There are 60 to 90 diverse types of lymphoma, and they are classified into smaller groups and subtypes for easy identification, treatment, and prognosis. Statistics say that among all diagnosed blood cancers in the country, 9 out of 10 are non-Hodgkin lymphoma, and only 1 in 10 cases is diagnosed as Hodgkin lymphoma. Categorization of lymphoma depends on many factors, such as:
- Whether it is a Hodgkin lymphoma or Non-Hodgkin lymphoma;
- Whether the abnormal cell that is replicating itself uncontrollably is a T cell or B cell;
- Where the mutated cell arises from;
- How the mutated cell appears under the microscope;
- Its growth pattern and how aggressively the cell replicates itself;
- How it impacts the body; and
- How it responds to treatment.
Named after Dr. Thomas Hodgkin, a British physician who first described this disease in the 1800s, Hodgkin lymphoma is a type of cancer in which the apparent presence of unusually large Reed–Sternberg cells, an abnormal type of B lymphocyte, is noticed first in the lymph nodes. Common in young adults in the age group between 15 and 35 years, Hodgkin lymphoma is subdivided into two types:
1. Hodgkin lymphoma
In this condition, the scar tissue or Reed–Sternberg cells are present in small numbers surrounded by normal white blood cells. The four subcategories of classic Hodgkin lymphoma are:
- Nodular Sclerosis Hodgkin lymphoma
- Mixed cellularity Hodgkin lymphoma
- Lymphocyte-rich Hodgkin lymphoma
- Lymphocyte-depleted Hodgkin lymphoma
2. Nodular Lymphocyte Predominant Hodgkin lymphoma
In this condition, large abnormal B cells called popcorn cells, variants of Reed–Sternberg cells, are present amidst the regular small B cells in the lymph nodes.
3. Non-Hodgkin lymphoma
Any lymphoma not identified as Hodgkin lymphoma is non-Hodgkin lymphoma (NHL) and can arise from both B-cells and T-cells. Some types of Non-Hodgkin lymphoma occur more commonly in children while some occur only amongst older adults. Non-Hodgkin lymphoma is further sub-categorized on the basis of factors like how fast they grow, whether they are indolent or aggressive, and which type of lymphocyte they develop from.
Some examples of these types of NHL are:
- Aggressive B-Cell Non-Hodgkin lymphoma
Burkitt lymphoma, Diffuse large B-cell lymphoma - Aggressive T-Cell Non-Hodgkin lymphoma
Anaplastic large cell lymphoma, Angioimmunoblastic T-cell lymphoma - Low-grade B-cell Non-Hodgkin lymphoma
Chronic lymphocytic leukemia/small lymphocytic lymphoma, Follicular lymphoma - Low-grade T-cell Non-Hodgkin lymphoma
Adult T-cell leukemia/lymphoma, Cutaneous T-cell lymphoma
Patients with lymphoma should visit their physician regularly and undergo the right diagnostic medical tests so they may be guided with the proper treatment options.