Cancer

Cancer is a group of diseases characterized by uncontrolled growth of tissue cells in the body and the invasion by these cells into nearby tissue and migration to distant sites. Cells are the building blocks of living things.
Cancer grows out of normal cells in the body. Normal cells multiply when the body needs them, and die when the body doesn't need them. Cancer appears to occur when the growth of cells in the body is out of control and cells divide too quickly. It can also occur when cells forget how to die.
There are many different kinds of cancers. Cancer can develop in almost any organ or tissue, such as the lung, colon, breast, skin, bones, or nerve tissue.

Hodgkin's lymphoma

Hodgkin's lymphoma — formerly known as Hodgkin's disease — is a cancer of the lymphatic system, which is part of your immune system.
In Hodgkin's lymphoma, cells in the lymphatic system grow abnormally and may spread beyond the lymphatic system. As Hodgkin's lymphoma progresses, it compromises your body's ability to fight infection.
Hodgkin's lymphoma is one of two common types of cancers of the lymphatic system. The other type, non-Hodgkin's lymphoma, is far more common.