Autopsy - An examination of the tissues and organs of a deceased person to determine the cause of death or the disease processes that existed prior to death.

Benign - An abnormal growth which will remain localized and which will not spread by the bloodstream or lymphatics to other tissues or organs.

Biopsy - The process of removing tissue from living patients for the purpose of diagnostic examination.

Block - Sometimes referred to as "paraffin block", this a cube of paraffin wax containing the tissue specimen, which allows the tissue to be cut into very thin slices ("sections") by a trained technologist using a special cutting instrument, the microtome. These thin sections of tissue are mounted on glass slides (see "slides") for ultimately viewing under the microscope by the pathologist. The tissue contained in the block is permanently preserved, and is an important source of diagnostic tissue if additional studies must be performed at any time in the future.

CAT Scan - Computerized axial tomography; a type of x-ray examination that allows the viewing of anatomic planes within the body (that is, images of slices through the body).

Clinical Pathologist - A pathologist specializing in analysis of samples of body fluids or tissues with respect to chemistry, microbiology (viruses and bacteria), hematology (blood), immunology (immune system), and other laboratory methods of analysis as they pertain to the diagnosis of disease and the care of patients

Cytology - The study of the structure, function, and chemistry of the cell.

Cytopathology - The study of disease changes within individual cells or cell types.

Diagnosis - The determination of the nature of a disease. In anatomic pathology, the diagnosis is made from microscopic examination of tissues. In clinical pathology, the diagnosis is made from chemical or cellular analysis of samples of body fluids. In cytopathology, diagnosis is made by microscopic examination of cells.

Frozen Section - A method of rapid diagnosis performed during surgery in which tissue obtained by biopsy is rapidly frozen, and thin slices are mounted on glass slides, stained, and examined under the microscope by the pathologist.

Malignant - An abnormal growth which can extend into ("invade") surrounding tissues or travel to other organs or tissues by the bloodstream or lymphatics ("metastasize"). Malignant tumors require aggressive treatment, often combinations of surgery, chemotherapy, and radiation therapy, in order to provide the possibility of a cure.

Microscope - An instrument that provides a greatly enlarged image of an object, allowing the viewing of features than cannot be seen with the naked eye. The microscopes routinely used by pathologists can enlarge images up to 1000 times.

MRI - Magnetic resonance imaging; an imaging method used by radiologists to view internal body structures using combinations of radio waves and magnetic fields.

Needle Aspiration - A method used by cytopathologists, using a hollow needle and syringe, to obtain cells for microscopic examination and diagnosis of disease.

Pap smear - The name given to the preparation of cells from the cervix on glass slides for microscopic examination by a cytopathologist; used most often for early detection of cancer of the cervix. The name is derived from Dr. Papanicolaou, the inventor of the procedure.

Pathologist - A physician who interprets and diagnoses the changes caused by disease in tissues and body fluids.

Pathology - The medical science, and specialty practice, concerned with all aspects of disease, but with special reference to the essential nature, causes, and development of abnormal conditions, as well as the structural and functional changes that result from the disease processes.

Pathology report - The written document that states the diagnostic opinion of the pathologist. Items included in the report include a careful documentation of the specimens received by the pathologist, a complete description of their appearance (size, color, presence of any visible abnormality), a report of all of the diagnostic findings after microscopic examination, and a complete documentation of all of the studies which were performed on the tissue. This report is a permanent part of the medical record, and the physician responsible for submitting the tissue to the pathologist receives a copy.

Slide - Also referred to a "glass slide," this is a rectangular sheet of glass measuring 1 x 3 inches, on which very thin slices ("sections") of tissue are placed for viewing under the microscope. Typically, the tissue sections are stained with one or more dyes to make the cellular features visible, and a very thin sheet of glass is glued over the surface to protect the tissue from damage. Glass slides properly prepared and stored can retain their original quality for many years, and are stored permanently. Being made of glass, they are subject to breakage if roughly handled.

Surgical Pathologist - A pathologist specializing in diagnosis of disease based on the visual and microscopic examination of tissues taken by biopsy from living patients.

ThinPrep™ - An alternative method to the Pap smear for preparing cells sampled from the cervix for microscopic examination. This method, a trademark of Cytyc Corporation, provides a more uniform dispersion of cells on the glass slide by first putting the cells into suspension in a liquid medium before depositing them on the slide.