Terms and Definitions

Pathology:  the study of disease.   

Pathologist: a medical doctor that specializes in pathology.  He or she is an expert at interpreting microscopic views of cells and body tissues.

Clinical Pathology: the subspecialty of pathology concerned with the theoretical and technical aspects of chemistry, immunology, hematology, and other fields as they pertain to the diagnosis of disease.

Anatomical Pathology: the subspecialty of pathology that pertains to the gross and microscopic study of organs and tissues removed for biopsy or during an autopsy, and also the interpretation of the results of such study.

Surgical Pathology: A field in anatomic pathology concerned with examination of tissues removed from living patients for diagnosis of disease.

FNA (Fine Needle Aspiration): a procedure that removes cells or fluid from tissues using a needle.

Bone Marrow Biopsy and Aspiration: a procedure in which a needle is inserted into a bone, usually the hip, to remove a small amount of bone marrow for microscopic examination.

Chemistry: the scientific study of composition, structure, properties, and interaction of chemicals.

Hematology: the study of the morphology of the blood and blood-forming tissues.

Immunology: the sub-field of biology that deals with the study of antigens and how humans fight off disease.

Cytology: the study of cells.

Biopsy: the removal of a small piece of tissue for microscopic examination or testing. Biopsies are generally performed either with a needle or during a surgical procedure. Unhealthy tissues are biopsied to diagnose disease; healthy tissue are biopsied for tissue-type matching for transplants.  

Antibody: a protein produced by the immune system in response to the presence of an antigen.  It defends the body against substances identified by the immune system as potentially harmful.

Antigen: a foreign or nonnative substance from the environment, such as chemicals, or formed within the body, such as viral or bacterial  toxins.  Recognized by the immune system as a threat.

Cancer: a general term used for more than 100 diseases that are characterized by uncontrolled, abnormal growth of cells.  For detailed information, see the American Cancer Society website.

Benign: not cancerous; does not invade or destroy the tissue in which it originated, or spread to other sites.

Malignant: a tumor that invades or destroys the tissue in which it originated and can spread to other sites via the bloodstream or lymphatic system.

Metastasis: the distant spread of a malignant tumor from it's site of origin.  This can occur by the bloodstream, through the lymphatic system, or across body cavities.

Lymph: fluid present within the lymphatic system.  Lymph consists of the fluids that bathes the tissues, which is derived from the blood and is drained by the lymphatic vessels.

Lymph nodes: a number of small swellings found at intervals along the lymphatic system.  Groups of nodes are found in many parts of the body.  They act as filters for the lymph, and prevent foreign particles from entering the bloodstream.

Lymphatic system: a network of vessels that conveys water, electrolytes, proteins, etc., in the form of lymph from the tissue fluids to the bloodstream.

Oncologist: a medical doctor who specializes in the diagnosis, treatment, and rehabilitation of patients with cancer.

Autopsy: post mortem examination.

Pap Test/Smear: short for Papanicolaou Test. A test used to detect cancer of the cervix.

Gross exam:  a description of what the specimen looks like to the naked eye. Also called the "gross" or "macroscopic".

Microscopic exam: a narrative description of the findings gained from examination of the specimen on a glass slide under the microscope.  Also called the "micro"

Diagnosis: determining the nature of a disorder by considering the patient's medical background, symptoms, and lab tests.

This information is provided as educational purposes only and is no substitute for specific medical advice.