Medical Glossary P

p53: A gene in the cell that normally inhibits the growth of tumors, which can prevent or slow the spread of cancer.

Palate (PAL-et): The roof of the mouth. The front portion is bony (hard palate), and the back portion is muscular (soft palate).

Palliative treatment: Treatment that does not alter the course of a disease, but improves the quality of life.

Palpation (pal-PAY-shun): A technique in which a doctor presses on the surface of the body to feel the organs or tissues underneath.

Pancreas: A gland located in the abdomen. It makes pancreatic juices, and it produces several hormones, including insulin. The pancreas is surrounded by the stomach, intestines, and other organs.

Pancreatectomy (pan-kree-a-TEK-to-mee): Surgery to remove the pancreas. In a total pancreatectomy, the duodenum, common bile duct, gallbladder, spleen, and nearby lymph nodes also are removed.

Pancreatic cancer: Cancer of the pancreas is a disease in which cancer (malignant) cells are found in the tissues of the pancreas. The pancreas is about 6 inches long and is shaped something like a thin pear, wider at one end and narrowing at the other. The pancreas lies behind the stomach, inside a loop formed by part of the small intestine.

Pancreatic juices: Fluids made by the pancreas. Pancreatic juices contain proteins called enzymes that aid in digestion.

Papillary tumor (PAP-i-lar-ee): A tumor shaped like a small mushroom with its stem attached to the inner lining of the bladder.

Papilledema (pap-il-eh-DEE-ma): Swelling around the optic nerve, usually due to pressure on the nerve by a tumor.

Pap test: Microscopic examination of cells collected from the cervix. It is used to detect changes that may be cancer or may lead to cancer, and it can show noncancerous conditions, such as infection or inflammation. Also called Pap smear.

Paralysis (pa-RAL-ih-sis): Loss of ability to move all or part of the body.

Paraneoplastic syndrome (pair-a-nee-o-PLAS-tik): A group of symptoms that may develop when substances released by some cancer cells disrupt the normal function of surrounding cells and tissue. Such symptoms do not necessarily mean that the cancer has spread beyond the original site.

Parotid cancer: Cancer of the salivary gland is a disease in which cancer (malignant) cells are found in the tissues of the salivary glands. Your salivary glands make saliva, the fluid that is released into your mouth to keep it moist and to help dissolve your food. Major clusters of salivary glands are found below your tongue (sublingual glands), on the sides of your face just in front of your ears (parotid glands), and under your jawbone (submaxillary glands).

Pediatric (pee-dee-AT-rik): Pertaining to children.

Pelvis: The lower part of the abdomen, located between the hip bones.

Penile cancer: Cancer of the penis, a rare kind of cancer in the United States, is a disease in which cancer (malignant) cells are found on the skin and in the tissues of the penis.

Percutaneous transhepatic cholangiography (per-kyoo-TAN-ee-us trans-heh-PAT-ik ko-LAN-jee-AH-gra-fee): A test sometimes used to help diagnose cancer of the pancreas. During this test, a thin needle is put into the liver. Dye is injected into the bile ducts in the liver so that blockages can be seen on x-rays.

Perfusion: The process of flooding fluid through the artery to saturate the surrounding tissue. In regional perfusion, a specific area of the body (usually an arm or a leg) is targeted and high doses of anticancer drugs are flooded through the artery to reach the surrounding tissue and kill as many cancer cells as possible. Such a procedure is performed in cases where the cancer is not thought to have spread past a localized area.

Perineal prostatectomy (pe-ri-NEE-al): Surgery to remove the prostate through an incision made between the scrotum and the anus.

Peripheral blood stem cell transplantation (per-IF-er-al): A procedure that is similar to bone marrow transplantation. Doctors remove healthy immature cells (stem cells) from a patient's blood and store them before the patient receives high-dose chemotherapy and possibly radiation therapy to destroy the leukemia cells. The stem cells are then returned to the patient, where they can produce new blood cells to replace cells destroyed by the treatment.

Peripheral stem cell support (per-IF-er-ul): A method of replacing blood-forming cells destroyed by cancer treatment. Certain cells (stem cells) in the blood that are similar to those in the bone marrow are removed from the patient's blood before treatment. The cells are given back to the patient after treatment.

Peristalsis (pair-ih-STAL-sis): The rippling motion of muscles in the digestive tract. In the stomach, this motion mixes food with gastric juices, turning it into a thin liquid.

Peritoneal cavity: The lower part of the abdomen that contains the intestines (the last part of the digestive tract), the stomach, and the liver. It is bound by thin membranes.

Petechiae (peh-TEE-kee-a): Tiny red spots under the skin; often a symptom of leukemia.

Pharynx (FAIR-inks): The hollow tube about 5 inches long that starts behind the nose and ends at the top of the trachea (windpipe) and esophagus (the tube that goes to the stomach).

Photodynamic therapy (fo-to-dy-NAM-ik): Treatment that destroys cancer cells with lasers and drugs that become active when exposed to light.

Pigmemt: A substance that gives color to tissue. Pigments are responsible for the color of skin, eyes, and hair.

Pineal gland (PIN-ee-al): A small gland located in the cerebrum.

Pineal region tumors: Types of brain tumors that occur in or around the pineal gland, a tiny organ near the center of the brain. The pineal region is very difficult to reach, therefore these tumors often cannot be removed.

Pineoblastoma (PIN-ee-o-blas-TOE-ma): A fast growing type of brain tumor that occurs in or around the pineal gland, a tiny organ near the center of the brain.

Pineocytoma (PIN-ee-o-sye-TOE-ma): A slow growing type of brain tumor that occurs in or around the pineal gland, a tiny organ near the center of the brain.

Pituitary cancer: Pituitary tumors are tumors found in the pituitary gland, a small organ about the size of a pea in the center of the brain just above the back of the nose. Your pituitary gland makes hormones that affect your growth and the functions of other glands in your body. Most pituitary tumors are benign. This means that they grow very slowly and do not spread to other parts of the body.

Pituitary gland (pih-TOO-ih-tair-ee): The main endocrine gland; it produces hormones that control other glands and many body functions, especially growth.

Plasma: The liquid part of the blood.

Plasma cells: Special white blood cells that produce antibodies.

Plasmacytoma: A tumor that is made up of cancerous plasma cells.

Plasmapheresis (plas-ma-fer-EE-sis): The process of removing certain proteins from the blood. Plasmapheresis can be used to remove excess antibodies from the blood of multiple myeloma patients.

Plastic surgeon: A surgeon who specializes in reducing scarring or disfigurement that may occur as a result of accidents, birth defects, or treatment for diseases (such as melanoma).

Platelets (PLAYT-lets): Blood cells that help clots form to help control bleeding. Also called thrombocytes.

Pleura (PLOOR-a): The thin covering that protects and cushions the lungs. The pleura is made up of two layers of tissue that are separated by a small amount of fluid.

Pleural cavity: A space enclosed by the pleura, thin tissue covering the lungs and lining the interior wall of the chest cavity. It is bound by serous membranes.

Pneumatic larynx (noo-MAT-ik): A device that uses air to produce sound to help a laryngectomee talk.

Pneumonectomy (noo-mo-NEK-to-mee): An operation to remove an entire lung.

Pneumonia (noo-MONE-ya): An infection that occurs when fluid and cells collect in the lung.

Positive Appearance Center: (PAC), the first of its kind anywhere, and a nonprofit facility, is an integral component of our psychosocial care program. It provides on site information, services, and products that help men and women with all types of cancer diagnoses to deal with the cosmetic and comfort side effects of treatment.

Positron emission tomography scan: For this type of scan, a person is given a substance that reacts with tissues in the body to release protons (parts of an atom). Through measuring the different amounts of protons released by healthy and cancerous tissues, a computer creates a picture of the inside of the body. Also called PET scan.

Postremission therapy: Chemotherapy to kill leukemia cells that survive after remission induction therapy.

Precancerous (pre-KAN-ser-us): A term used to describe a condition that may or is likely to become cancer.

Precancerous polyps: Growths in the colon that often become cancerous.

Prednisone: A drug often given to multiple myeloma patients along with one or more anticancer drugs. Prednisone appears to act together with anticancer drugs in helping to control the effects of the disease on the body.

Preleukemia (PREE-loo-KEE-mee-a): A condition in which the bone marrow does not function normally. It does not produce enough blood cells. This condition may progress and become acute leukemia. Preleukemia also is called myelodysplastic syndrome or smoldering leukemia.

Primitive neuroectodermal tumors (NOO-ro-ek-toe-DER-mul): A type of brain tumor that recent research suggests develops from primitive (developing) nerve cells that normally do not remain in the body after birth. Primitive neuroectodermal tumors are often called medulloblastomas.

Proctoscopy (prok-TOS-ko-pee): An examination of the rectum and the lower end of the colon using a thin lighted instrument called a sigmoidoscope.

Proctosigmoidoscopy (PROK-toe-sig-moid-OSS-ko-pee): An examination of the rectum and the lower part of the colon using a thin, lighted instrument called a sigmoidoscope.

Progesterone (pro-JES-ter-own): A female hormone.

Prognosis (prog-NO-sis): The probable outcome or course of a disease; the chance of recovery.

Prophylactic cranial irradiation (pro-fi-LAK-tik KRAY-nee-ul ir-ray-dee-AY-shun): Radiation therapy to the head to prevent cancer from spreading to the brain.

Prostatectomy (pros-ta-TEK-to-mee): An operation to remove part or all of the prostate.

Prostate cancer: Cancer of the prostate, a common form of cancer, is a disease in which cancer (malignant) cells are found in the prostate. The prostate is one of the male sex glands and is located just below the bladder (the organ that collects and empties urine) and in front of the rectum (the lower part of the intestine). The prostate is about the size of a walnut. It surrounds part of the urethra, the tube that carries urine from the bladder to the outside of the body. The prostate makes fluid that becomes part of the semen, the white fluid that contains sperm.

Prostate gland (PROS-tate): A gland in the male reproductive system just below the bladder. It surrounds part of the urethra, the canal that empties the bladder. It produces a fluid that forms part of semen.

Prostate-specific antigen: A protein whose level in the blood goes up in some men who have prostate cancer or benign prostatic hyperplasia. Also called PSA.

Prostatic acid phosphatase (FOS-fa-tase): An enzyme produced by the prostate. Its level in the blood goes up in some men who have prostate cancer. Also called PAP.

Prosthesis (pros-THEE-sis): An artificial replacement for a body part.

Prosthodontist (pros-tho-DON-tist): A dentist with special training in making replacements for missing teeth or other structures of the oral cavity to restore the patient's appearance, comfort, and/or health.

Proteins (PRO-teenz): Substances that are essential to the body's structure and proper functioning.

PTC (percutaneous transhepatic cholangiography) (per-kyoo-TAN-ee-us trans-heh-PAT-ik ko-LAN-jee-AH-gra-fee): A test sometimes used to help diagnose cancer of the pancreas. During this test, a thin needle is put into the liver. Dye is injected into the bile ducts in the liver so that blockages can be seen on x-rays.