Glossary of Medical Terms

Anesthesia: Numbing medicine. Anesthesia can be local (at a specific site, either by injection, spray, or cream), with the patient awake, or general (administered intravenously or by inhalation), in which the patient is generally asleep and breathing is assisted by a respirator or ventilator (breathing machine).

Biopsy: Taking a sample of tissue with a needle or with surgery to send to the pathology laboratory so it can be examined under the microscope to determine if cancer is present.

Bone marrow: The site of development of blood cells, including red blood cells that carry oxygen in the blood, white blood cells that fight infection, and platelets that help the blood clot. In a bone marrow biopsy, a sample of bone marrow is removed, usually from the pelvis, to determine if malignant cells are present.

Catheter: A small tube that allows access to a particular part of the body. These may be placed through the skin

Chemotherapy: Strong medication to kill cancer cells. Most chemotherapy works by killing rapidly dividing cells. Unfortunately, some normal cells divide rapidly, such as the cells in the bone marrow responsible for making blood cells.

Cerebrospinal fluid (CSF): The fluid surrounding the brain and spinal cord.

Cytology: Analysis of cells under the microscope.

Fingerstick: A method of obtaining blood for a blood test by sticking a small needle in a fingertip and obtaining a few drops of blood to put on a glass slide.

Intrathecal: Adjective: a route of administration for medication (such as chemotherapy) directly into the cerebrospinal fluid (CSF), the fluid around the brain and spinal cord. Intrathecal medication can be injected by performing a lumbar puncture (LP; also known as a spinal tap), a procedure in which a needle is inserted into the back to take fluid from around the spinal cord, or by using an Omaya, a sterile reservoir and tube that is implanted neurosurgically into the head.

Intravenous (IV): Adjective: a route of administration into a blood vessel (vein) of fluids, medication, or blood products. Noun: a small plastic tube placed into a vein (blood vessel) to administer the above items.

Leukovorin rescue: After administration of methotrexate, which is toxic chemotherapy, the leukovorin “rescue” involves repeated doses of an intravenous medication called leucovorin which helps combat the toxic effects of methotrexate on the body.

Lumbar puncture (LP): a procedure in which a needle is inserted usually into the back between the third and fourth lumbar vertebrae (back bones) into the sac of fluid around the spinal cord to remove cerebrospinal fluid (CSF), the fluid around the spinal cord and brain. Synonym: spinal tap.

Lymph nodes: “Glands” containing lymphocytes, a type of white blood cell that participates in defending the body from infection. Lymph nodes can become enlarged in infections, inflammatory conditions, and malignant tumors.

Lymphocytes: A type of white blood cells that normally participate in defending the body from infection. There are different types of lymphocytes (B cells and T cells) with specialized immune functions. In autoimmune diseases, the lymphocytes attack the body as if it were foreign.

Lymphoma: A malignancy in which lymphocytes grow uncontrollably. Lymphoma can involve multiple body sites, including lymph nodes (the glands that swell up during infection), bone marrow (where new blood cells are produced), and other organs.

Magnetic resonance imaging (MRI): An imaging test applicable to any part of the body. MRI uses strong magnetic fields to make signals that are displayed as images.

Median survival: The amount of time for which half of the patients live less and half live more. A median survival of one year, for example, means that half of the patients live less than one year and half live more than one year.

Mediport: A type of catheter (sterile plastic tube) that can be placed into a vein under sterile conditions to allow access for intravenous medications. The tip of the tube is in the vein, and the port or reservoir that is injected is placed underneath the skin. To access the Mediport, the nurse or doctor must pierce the skin with a needle.

Methotrexate: A form of chemotherapy that attacks rapidly dividing cells.

Monoclonal antibody: A pure population of proteins that attack a specific target, such as a particular cell surface marker in the body. Monoclonal antibodies are an example of “targeted therapy,” in which the treatment is specifically designed to attack a particular target, rather than to cause generalized death of rapidly dividing cells. Because monoclonal antibodies are more specific, they generally have fewer side effects than chemotherapy.

Nadir: In general parlance, “nadir” means the lowest point (opposite of zenith, the highest point). In medicine, “nadir” refers to having an extremely low count of white blood cells responsible for fighting infection in the body.

Neutropenia: Low count of neutrophils, a group of white blood cells that fight infection.

Neutrophil: A type of white blood cell, also called a polymorphonuclear leukocyte or “poly,” that fight infection.

Omaya: A sterile tube that has its tip in the fluid around the brain (cerebrospinal fluid, or CSF). The Omaya must be placed neurosurgically by drilling a hole in the skull and inserting the catheter through brain tissue until it reaches one of the lateral ventricles, fluid-filled structures in the brain that contain CSF. Chemotherapy can be administered through the Omaya, and fluid can be removed from the Omaya (“Omaya tap”) to determine if malignant cells are present.

pH: A quantitative measure of acidity. A fluid pH of 7.0 is “neutral,” <7.0>7.0 is “alkaline” or “basic.” Oral bicarbonate can make the urine more alkaline.

Port: The general term for a catheter (sterile plastic tube) placed into a vein to allow access for IV medications. A Mediport is a specific type of port.

Prednisone: An oral steroid that can be used to treat a variety of diseases, including lymphomas. Prednisone can cause weight gain, sleep disturbances, and manic episodes.

R-CHOP: An intravenous chemotherapy regimen used to treat some lymphomas. R is Rituximab, a monoclonal antibody directed against the specific malignant B lymphocytes; C is cyclophosphamide; H is doxorubicin (formerly Adriamycin); O is vincristine (originally called Oncovin); and P is prednisone, an oral steroid.

Remission: Control of active malignancy. Patients in remission may stay healthy or may redevelop malignancy in the future (“recurrence”).

Stage IV: Disseminated malignancy. This is the most advanced stage of cancer, when sites other than the location of the index tumor are involved, and has the worst outcome.

Targeted therapy: A method of treating cancer in which the drug specifically attacks the malignant cells, without significant damage to normal cells. Hopefully, this approach will become available for many different kinds of cancer, providing strong and effective anti-cancer treatment with minimal side effects.

Ventricles of the brain: Four fluid-filled structures in the brain that contain cerebrospinal fluid (CSF) and communicate with the CSF around the brain and spinal cord. The brain has two lateral ventricles (one on the right and one on the left) and two midline ventricles (the third and the fourth). An Omaya catheter usually has its tip in a lateral ventricle of the brain.