Dictionary

pneumonia, double Pneumonia in both lungs. Also known as bilateral pneumonia.

pneumonia, giant cell A deadly but fortunately rare complication of measles that tends to strike children who are immunodeficient from leukemia or AIDS. The lung tissue shows multinucleated giant cells lining the alveoli (air sacs) of the lungs. Also known as Hecht’s pneumonia.

pneumonitis, radiation Inflammation of the lungs that results from radiation. Radiation pneumonitis typically occurs after radiation treatments for cancer within the chest or breast. Radiation pneumonitis usually manifests itself 2 weeks to 6 months after completion of radiation therapy. Symptoms include shortness of breath upon activity, cough, and fever. If radiation pneumonitis persists, it can…

plasma cell A type of white blood cell that produces and secretes antibodies. A plasma cell is a fully differentiated, mature lymphocyte in the B cell lineage. As with most cell types, plasma cells can mutate to give rise to cancer. Plasma cell malignancies include plasmacytoma, multiple myeloma, Waldenstrom macroglobulinemia, and plasma cell leukemia. Also…

plasma donation The donation or sale of blood plasma for use in medical or other products. Unlike blood donors, most plasma donors in the US are paid. The procedure is done in a walk-in facility, where whole blood is taken through an IV needle and separated into plasma and blood cells. The blood cells are…

plasmacyte See plasma cell.

plasmacytoma Cancer of the plasma cells (white blood cells that produce antibodies) that may turn into multiple myeloma.

plasmapheresis A procedure in which whole blood is taken from a person and separated into plasma and blood cells; the plasma is removed and replaced with another solution, such as saline solution, albumin, or specially prepared donor plasma; and the reconstituted solution is then returned to the patient. Plasmapheresis is used in the treatment of…

Plasmodium The genus of the class of Sporazoa that includes the parasite that causes malaria. Plasmodium is a type of protozoa, a single-celled organism that is able to divide only within a host cell. The main types of Plasmodium are P. falciparum, the species that causes falciparum malaria, the most dangerous type of malaria; P….

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. Many plastic surgeons also perform cosmetic surgery that is unrelated to medical conditions.

plastic surgery A surgical specialty that is dedicated to reconstruction of facial and body defects due to birth disorders, trauma, burns, and disease. Plastic surgery is also involved with the enhancement of the appearance of a person through cosmetic surgery.

platelet An irregular, disc-shaped element of blood that assists in blood clotting. During normal blood clotting, platelets group together (aggregate). Although platelets are often classified as blood cells, they are actually fragments of large cells called megakaryocytes. Also known as thrombocyte. See also blood cell.