The following provides definitions and descriptions for key terms related to the field of anatomical pathology.

the subspecialty of pathology that pertains to the diagnosis of disease based on the macroscopic, microscopic, biochemical, immunologic and molecular examination of organs and tissues removed for biopsy, during surgery, or during postmortem examination, and also the interpretation of the results of such study.

the scientific study of the nature of disease, and its causes, processes, development, and consequences.

a doctor who specializes in identifying diseases by studying cells and tissues under a microscope.

The process of identifying the manifestations so that the disease can be named; the name of the disease a patient has.

a group of neoplastic diseases in which there is a transformation of normal cells into malignant cells. The cells proliferate in an abnormal way resulting in a malignant, cellular tumor.

an alteration or abnormality in a tissue or cell; a pathological change.

of no danger to health, especially relating to a tumorous growth; not malignant; something that does not metastasize and treatment or removal is curative.

tending to become worse, deteriorate and produce death or having the properties of anaplasia, invasiveness, and metastasis; malignant tumors.

a malignant new growth made up of epithelial cells tending to infiltrate surrounding tissues and to give rise to metastases.

a tumor that has transferred from one organ or part to another not directly connected to it.

the removal and examination of tissue, cells, or fluids from the living body; a procedure that involves obtaining a tissue specimen for microscopic analysis to establish a precise diagnosis. Most biopsies are small samplings of an area in which disease is suspected. These are called “incisional” biopsies and additional surgery or treatment may be recommended after the diagnosis is made.

any of several methods, as a fine needle aspiration or core biopsy, for obtaining a sample of cells or tissue by inserting a hollow needle through the skin and withdrawing a sample of  tissue or organ to be examined

the therapeutic surgical removal of an entire diseased area or organ (and occasionally multiple organs).

the name given to the whole intervention by the pathologist, which includes not only frozen section but also gross evaluation of a specimen, examination of cytology preparations taken on the specimen, and aliquoting of the specimen for special studies (e.g. molecular pathology techniques, flow cytometry). The report given by the pathologist to the surgeon is usually limited to a “benign” or “malignant” diagnosis.

a rapid diagnostic procedure where a thin slice of tissue is cut from a frozen specimen, mounted onto a glass slide, stained, and used for microscopic diagnosis. The procedure usually takes only 10-20 minutes and can be performed during patient surgery.

the study of cells and tissue on the microscopic level; a branch of anatomy that deals with the minute structure of animal and plant tissues as discernible with the microscope.

technical histology concerned specifically with preparing (i.e,  fixing, processing, embedding, sectioning, and staining) histological specimens.

a technician who specializes in histotechnology.

a branch of biology dealing with the structure, function, multiplication, pathology, and life history of cells.

a specialty in medical technology concerned with the identification of cells and cellular abnormalities (as in cancer).

a medical technologist trained in Cytotechnology.

a method or a test for the early detection of cancer especially of the uterine cervix that involves staining exfoliated cells by a special technique which differentiates diseased tissue — called  Papanicolaou smear, Papanicolaou test, or Pap test.

the process of obtaining a sample of cells and bits of tissue for examination by applying suction through a fine needle attached to a syringe, abbreviation FNA.

the study of biochemical and biophysical cellular mechanisms as the basic factors in disease.

method of measuring fluorescence from stained cells that are in suspension and flowing through a narrow orifice, usually in combination with one or two lasers to activate the dyes; used to measure cell size, number, viability, and nucleic acid content with the aid  selected staining reagents.

the demonstration of tissue specific antigens by the use of antibody markers that contain either fluorescent dyes or enzymes such as horseradish peroxidase