Classifying and Staging Hodgkin Lymphoma
Classification of Hodgkin lymphoma
A lymphoma is classified as Hodgkin lymphoma if the Reed-Sternberg cell is detected. However, Hodgkin lymphoma is further classified into subtypes which describe the disease in more detail such as what the affected lymph nodes look like, what other cells are present and what characteristics the cells have.
The two main subtypes of Hodgkin lymphoma are:
Nodular lymphocyte predominant Hodgkin lymphoma
- This occurs more often in older adults and grows slower than classical Hodgkin lymphoma. It is often diagnosed at an early stage when "B symptoms" are not yet present.
Classical Hodgkin lymphoma
- This is further divided into 4 subtypes: nodular sclerosing, mixed cellularity, lymphocyte rich and lymphocyte depleted.
- Nodular sclerosing is the most common Hodgkin lymphoma subtype, although it is less common in older adults diagnosed later in life.
- Lymphocyte depleted Hodgkin lymphoma is very rare.
- These various subtypes tend to be treated in the same way.
Staging Hodgkin lymphoma
"Staging" is a medical term used to describe the extent to which the lymphoma has spread within the body. The stage is determined by:
- The number and location of lymph nodes affected.
- Whether the affected lymph nodes are above, below or on both sides of the diaphragm (the large, dome-shaped muscle under the ribcage that separates the chest from the abdomen).
- Whether the cancer has spread to the bone marrow or to other organs such as the liver.
A diagramattical example of the path of Hodgkin Lymphoma using
the Ann Arbor Staging System.
The most common method of staging is called the Ann Arbor Staging System, which can be summarised as follows:
Ann Arbor Staging System
||What it means
The NHL is in only one group of lymph nodes
Two or more groups of lymph nodes are affected but they are all either above or below the diaphragm, either all in the chest or all in the abdomen
Two or more groups of lymph nodes are affected in both the chest and the abdomen
NHL is in at least one organ (e.g. bone marrow, liver or lungs) as well as the lymph nodes
Each stage of Hodgkin lymphoma may also be classified as "A" or "B". People with a B classification have one or more of the following B symptoms:
- Unexplained weight loss of more than 10% in the six months before diagnosis
- Unexplained fever with temperatures above 38°C
- Drenching night sweats
For example, if your Hodgkin lymphoma is on both sides of your diaphragm and you have been having night sweats, the doctor will refer to your disease as stage 3B. Or, if your disease is in several lymph nodes above your diaphragm (e.g. your neck and chest) and you have no B symptoms, your doctor will refer to your disease as stage 2A.
Medical tests for staging Hodgkin lymphoma
In addition to a lymph node (and perhaps also a bone marrow) biopsy, the doctor may require that you have other medical tests to identify the stage of disease. Some of these tests may include images and scans, such as:
- A procedure where low dose radiation beams are used to provide images of the inside of the body for diagnostic purposes.
CT scan/CAT scan
- A series of X-rays that provide detailed, three-dimensional images of the inside of the body.
MRI (magnetic resonance imaging)
- An MRI is similar to a CT scan, but uses magnets instead of X-rays.
- A safe amount of radioactive gallium is injected into the person, after which an X-ray is performed to detect where the radioactive gallium makes the tumour(s) visible.
PET (positron emission tomography) scan
- This is similar to a Gallium scan, except it is radioactive glucose which is injected into the person and is taken up preferentially by cells with a high metabolic (energy) activity, such as cancer cells. A scanner is then used to visualise the areas of the body where the radioactive glucose is concentrated.