What is Lymphoma?

To understand lymphoma, and perhaps any type of cancer, it is useful to first understand a couple of ‘human-body basics’. It is estimated that the human body is made of over 50 trillion cells (50,000,000,000,000). It is also estimated that every hour, the human body has to replace over 1 billion cells (yes, 1,000,000,000!). Every one of these 50 trillion cells are organized into one of 4 tissues, which include epithelial tissue, connective tissue, muscle and nervous tissue.

Epithelial tissue lines various organs and plays a role in protecting the body from the outside environment, secreting proteins necessary to fend off infection, and in absorbing nutrients. The overwhelming number of cancers are derived from epithelial tissues (breast, prostate, lung, colon, ovarian, bladder, for example). Connective tissue includes bone and ligaments, as well as all the cells that make up the blood, or hematopoietic system. Muscle tissue makes up muscle, and nervous tissue makes up the brain, spinal cord, and peripheral nerves.

What is important to keep in mind, is that these 4 tissues are assembled in various ways to make up the 78 different organs that together make up the human body. These 78 different organs are then configured into systems or networks, which define the 13 different organ systems that make up the human body. So, when someone says cancer to an oncologist, the doctor is thinking: (1) which organ (lung, breast, prostate, blood, colon, etc.), and (2) what cell (epithelial, hematopoietic, mesenchymal, nervous, etc.).