Cancer is a group of many related diseases. All cancers begin in cells
, the body's basic unit of life. Cells make up tissues, and tissues make up the organs of the body.
Normally, cells grow and divide to form new cells as the body needs them. When cells grow old and die, new cells take their place. Sometimes this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor
Tumors can be benign or malignant.
Benign tumors are not cancer.
Usually, doctors can remove them. Cells from benign tumors do not spread to other parts of the body. In most cases, benign tumors do not come back after they are removed. Most important, benign tumors are rarely a threat to life.
Malignant tumors are cancer.
They are generally more serious. Cancer cells can invade and damage nearby tissues and organs. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or the lymphatic system. That is how cancer cells spread from the original (primary
) tumor to form new tumors in other organs. The spread of cancer is called metastasis
Although lymphomas are generally divided into two general types, Hodgkin and Non-Hodgkin, there are actually many different types of this cancer, including:
Multiple Myeloma and Other Plasma Cell Neoplasms
Mycosis Fungoides and the Sézary Syndrome
Primary CNS Lymphoma
Lymphoma begins in the lymphocytes
of the immune system and presents as a solid tumor of lymphoid cells. The cancerous cells often originate in lymph nodes, presenting as an enlargement of the node (a tumor). There are many types of lymphomas, and in turn, lymphomas are a part of the broad group of diseases called hematological neoplasms.
The lymph system (also known as the lymphatic system) is composed mainly of lymphoid tissue, lymph vessels, and a clear fluid called lymph.
Most of the cells in lymphoid tissue are lymphocytes, a type of white blood cell. The two main types of lymphocytes are B lymphocytes (B cells) and T lymphocytes (T cells). Both types can develop into lymphoma cells, but B-cell lymphomas are much more common than T-cell lymphomas in the United States.
The major sites of lymphoid tissue are:
Lymph nodes are bean-sized organs throughout the body that are connected by a system of lymphatic vessels. These vessels are like veins, except that instead of carrying blood, they carry lymph and immune system cells.
The spleen is an organ under the lower part of the rib cage on the left side of the body. The spleen makes lymphocytes and other immune system cells to help fight infection.
The thymus lies behind the upper part of the breastbone and in front of the heart.
Adenoids and Tonsils:
These are collections of lymphoid tissue located at the back of the throat.
The stomach and intestines as well as many other organs also contain lymphoid tissue.
The bone marrow makes red blood cells, blood platelets, and white blood cells. Lymphomas sometimes start from bone marrow lymphocytes.
Non-Hodgkin Lymphoma (NHL)
NHL is most common in adults, although it is a common childhood cancer. This type of lyphoma is the sixth most common cancer in men and the fifth most common cancer in women. It is also the ninth most common cause of cancer death in men and sixth most common cause of cancer death among women.
Lymphomas are based on how they look under a microscope, the chromosome features of the lymphoma cells, and the presence of certain chemicals on the surface of the cells. More common types of lymphoma are listed below according to whether they are B-cell or T-cell lymphomas.
B-cell lymphomas make up most (about 85%) of non-Hodgkin lymphomas in the United States. One of the more common types of non-Hodgkin lymphoma in the United States, accounting for about 1 out of every 3 cases, is Diffuse Large B-Cell Lymphoma (DLBCL.) This type of cancer occurs mostly in patients who are older, with the average age of mid-60s.
Starting usually as a quickly growing mass in an internal lymph node, such as the chest or abdomen or in a lymph node that you can feel, such as the neck or armpit, it can grow in other areas such as the intestines, bone, or even the brain or spinal cord.
Nearly 20% of lymphomas in the United States are follicular lymphoma. The average age for people with this lymphoma is about 60 and it is not often found in very young people. Most often, this lymphoma occurs in many lymph node sites in the body, as well as in the bone marrow.
Follicular lymphomas are often slow-growing, but they are hard to cure. Over time, about 30% of cases in follicular lymphomas change into a B-cell lymphoma.
Many T-cell lymphomas exist with the most common being Precursor T-Lymphoblastic Lymphoma. This type makes up less than 15% of non-Hodgkin lymphomas in the United States and normally starts in the thymus gland (where many T cells are created.) It can grow into a large tumor normally found in the area around the heart and behind the breast bone.
Patients are most often young adults. This lymphoma is fast-growing, however, it is a high percentage of patients who are cured if it is diagnosed before it has spread to the bone marrow.
Other T-cell Lymphomas include:
Peripheral T-cell Lymphomas
Cutaneous T-cell Lymphomas (Mycosis Fungoides, Sezary Syndrome)
Angioimmunoblastic T-cell Lymphoma
T-cell Lymphoma, Nasal Type
Enteropathy type T-cell Lymphoma
Subcutaneous Panniculitis-like T-cell Lymphoma
Anaplastic Large Cell Lymphoma
Peripheral T-cell Lymphoma Unspecified
which is the name given to T-cell lymphomas that don't fit into any of the above groups and make up nearly half of all T-cell lymphomas. As a group, these lymphomas tend to be widespread and grow quickly.
Sometimes, Non-Hodgkin Lymphomas may be difficult to diagnose. Consult with your doctor to ensure that accurate testing is completed to properly receive care.