A collection of pus

A cancer (malignant neoplasm) derived from glandular tissues.

A benign neoplasm (tumor) composed of glandular tissue.

Adhesion molecules

A large family of molecules occurring at the surfaces of cells. They allow cells to adhere to other cells of the same or different type, or to connective tissue elements such as collagen.

Fat cell

Autosomal recessive disorder caused by failure to metabolize homogentisic acid. This accumulates in tissues (cartilage) which becomes black (ochronosis).

One of a pair of hereditary units (genes).

Deposition of an eosinophilic, Congo red positive proteinaceous material between cells in various tissues of the body and in a variety of clinical settings.

Focal dilatation within the cardiovascular system that may rupture spontaneously causing catastrophic hemorrhage.

Process of developing new blood vessels (neovascularization)

Molecule produced by B-lymphocytes (plasma cells) which serves to opsonize bacteria (prepare them for phagocytosis) and neutralize viruses and toxins. Known also as an immunoglobulin, the protein includes a specific sequence of amino acids allowing it to interact only with the antigen that provoked its production.

Antigen

Any substance capable of producing an immune response, for example the production of an antibody.

APC

A tumor suppressor gene named after the inherited condition adenomatous polyposis coli (see FAP) and the first commonly occurring tumor suppressor gene to be identified through the study of a rare familial type of cancer. Also stands for antigen presenting cell.

High energy form of the nucleoside adenosine (adenosine triphosphate).

Acquired reduction in cell size or size of an organ.

Localized intimal thickening associated with fibrosis, accumulation of lipid and smooth muscle cell proliferation.

The process of arterial injury (‘hardening’) that is caused by inflammatory damage affecting the intimal lining of the vessel.

Autopsy

The post mortem examination of a body, the term meaning to see for oneself. Also described as necropsy.

Chromosome other than the X or Y chromosome.

A common type of (non-metastasizing) skin cancer.

In the context of DNA and RNA describes the chemical compounds adenine and guanine (purines) and thymine, cytosine and uracil (pyrimidines). Linked to a simple sugar (deoxyribose) molecule, the bases are termed nucleosides (adenosine, guanosine, thymidine, cytidine and uridine). Within DNA or RNA, the nucleosides are phosphorylated as nucleotides.

The removal and examination of a small piece of tissue in order to achieve a diagnosis by microscopic examination.

The laying down of calcium in tissues. Dystrophic calcification occurs in diseased tissues and metastatic calcification occurs in normal tissues as a result of hypercalcemia (raised plasma calcium).

Class of molecules including simple sugars, starches, plant fibers and gums.

Malignant neoplasm of epithelial origin.

Neoplasm derived from cells of the diffuse endocrine system.

Carcinoma that is still limited to an epithelial surface (i.e. has not invaded through the basement membrane or developed potential to spread to distant sites).

Cluster designation. Agreed nomenclature for leukocyte cell membrane antigens.

Branch of laboratory medicine involved with the detection and quantification of chemical substances in blood, urine and other fluids.

Chemical attractant of motile cells.

Treatment (generally of cancer) with chemical agents.

Material within nucleus made up of DNA and protein.

Discrete unit within the nucleus of the cell comprising multiple genes. A human cell contains twenty two pairs of chromosomes together with either two X chromosomes (in females) or an X and Y chromosome (in males).

Disease of the liver in which the normal architecture is permanently altered and liver function is impaired. Alcohol and hepatitis viruses are important causes but there are many others.

To reproduce multiple copies of a cell (or gene) from a single cell (or gene). Cloning of a gene implies that the gene has been localized within a particular chromosome, isolated and sequenced (meaning that the sequence of bases has been determined).

The process of clotting culminating in the conversion of fibrinogen to fibrin.

Commonest type of ischemic necrosis.

The sequence of three bases in DNA which codes for a specific amino acid (the building blocks of proteins).

Protein found in extracellular matrix of connective tissues that is either fibrillary or amorphous in structure.

System of plasma enzymes which facilitates the acute inflammatory process.

Accumulation of blood within an organ due to reduced venous outflow.

Tissue that supports and provides the structural framework for parenchymal tissues. The key connective tissue cell is the collagen secreting fibroblast.

Chronic granulomatous inflammatory disorder affecting gut (mainly intestines).

Collection of fluid or semi-solid material within a sac with an epithelial lining.

Chemical mediator or growth factor secreted by cells (principally lymphocytes and monocyte derived cells).

Laboratory diagnostic service involving the microscopic study of cells as opposed to tissues (for example cervical smears).

The formation within a cancer of a dense collagenous stroma.

Differentiation

The process whereby specialized cells are derived from uncommitted stem cells (see stem cells).

A blind ending sac.

Hereditary effect caused by a single mutated gene.

Deoxyribonucleic acid constitutes the primary genetic material of most living organisms and is composed of four bases (G, C, A and T) (see base). DNA is duplicated by replication and forms the template for transcribing RNA (see RNA).

A gene which normally repairs genetic damage but fails to do so when it is itself mutated or lost. Mutation or loss of both copies leads to a state of hypermutability and hence carcinogenesis.

Disordered growth and differentiation. Sometimes used to indicate a pre-invasive neoplastic change (e.g. in the gut).

Dilatation of a duct or tube.

Presence of increased amounts of fluid within the extracellular compartment.

An exudate in a serous cavity (pericardial, pleural or peritoneal).

A microscope employing a beam of electrons instead of a light source in order to achieve magnification beyond the range of a light microscope (x 1,000 to x 500,000).

Passage of a mass within the bloodstream from a point of origin to a point of impaction.

Cytoplasmic system of membranous cisternae which is the site of protein synthesis (rough) and lipid synthesis (smooth).

Flattened and highly versatile cell lining blood vessels and forming the endothelium.

A biological molecule, usually a protein, which catalyses (activates) chemical reactions.

White blood cell with large eosinophilic granules with multiple inflammatory roles.

Tissue which lines hollow organs or covers surfaces such as the skin.

The primary cause of a disease

Protein rich fluid in an extracellular site that has been derived from blood plasma. May be serous, fibrinous or purulent.

Describes a condition that is inherited and therefore affects multiple family members.

Inherited disorder caused by mutation of the APC gene in which affected subjects develop multiple precancerous polyps (adenomas) of the large intestine.

Form of necrosis complicating acute pancreatitis that is accompanied by calcification.

Coagulated form of the plasma protein fibrinogen.

Describes an appearance seen in vasculitis (acute inflammation of vessel wall) in which there is fibrin deposition. A misnomer.

Spindle shaped connective tissue cell which secretes collagen.

The laying down of collagen rich connective tissue.

A form of biopsy in which groups of cells are obtained by means of a fine needle.

A track connecting two epithelial surfaces that is lined by granulation tissue.

Combination of necrosis (usually ischemic) and bacterial invasion causing putrefaction.

Sequence of DNA coding for a single protein.

Cell responsible for the generation of sperm or eggs (ova).

Large molecule formed of glucose and the form in which glucose is stored.

In relation to cancer describes the level of aggressiveness (low grade = low aggressiveness, high grade = high aggressiveness).

Newly generated form of connective tissue involved in the process of healing.

Localized collection of macrophages (histiocytes).

Form of chronic inflammation in which granulomas are present.

Family of proteins that rescue other proteins following cell injury.

Bacterium responsible for chronic inflammation of the lining of the stomach (chronic gastritis).

Branch of laboratory and clinical medicine focussing on diseases of blood (leukemia, anemia and bleeding disorders).

Form in which iron is stored. A partially denatured form of ferritin.

The physiological process of hemorrhage arrest.

Inherited form of large intestinal cancer caused by mutation in a DNA mismatch repair gene.

Inflammatory mediator stored in mast cell, platelets and other tissues that causes vasodilatation and increased vascular permeability.

A form of classification of neoplasms (tumors) that is based on the tissue type constituting the lesion.

Branch of laboratory medicine that is equivalent to anatomical pathology or surgical pathology.

Chemical messenger (usually a protein or steroid) produced by an endocrine gland. Following its release into the blood stream a hormone acts on tissues at a distant site.

One of four fluids believed (from the time of the Greeks till the nineteenth century) to underlie states of health and disease. An excess of one of these (black bile) was thought to be the cause of cancer.

Microscopic appearance that is pink, homogeneous and ‘glassy’.

Form of reversible cell injury.

Increased volume of blood in an organ caused by increased arterial flow.

An increase in cell numbers leading to enlargement of a tissue or organ.

Excessive and destructive immune response.

Increase in cell size or size of an organ.

State of reduced supply of oxygen.

Type of protein that functions as an antibody. There are five classes: IgG, IgM, IgA, IgD and IgE.

A form of tissue staining utilizing the specific binding properties of antibodies.

Area of ischemic necrosis. Infarction is the process of ischemic necrosis.

Reduction in blood supply to tissues.

Dissolution of nuclei seen in a necrotic cell.

Fragmentation of nuclei seen in a necrotic cell.

Macrophage found in liver.

Cell type that proliferates continuously.

Malignancy of white blood cells: lymphocytes, monocytes or myeloid cells.

The close proximity of two genetic sites (loci) within a chromosome.

Brown wear and tear pigment found in autophagic vacuoles.

Type of ischemic necrosis occurring in the brain.

A system of fine vessels which serves to conduct excess fluid from the spaces surrounding cells (interstitium) back into the blood system. See lymph nodes.

Bean-sized organ (‘gland’) found throughout the lymphatic system constituted by lymphocytes and other cells responsible for immune defense.

White blood cell responsible for the orchestration of immunity to infection by micro-organisms. B lymphocytes produce antibody and T lymphocytes have helper (CD4), suppressor (CD8) and cytotoxic (CD8) roles.

Malignant tumor of lymphoid cells arising in lymph nodes or extranodal sites where lymphocytes aggregate together.

Cytoplasmic organelles containing enzymes used in autophagy and phagocytosis.

Enzyme which lyses bacterial cell walls. Also known as muramidase.

Large phagocytic cell with multiple inflammatory functions.

Adjective indicating the cancerous nature of a lesion (having the capacity for local invasion and metastasis).

Malignant tumor composed of melanin producing cells (melanocytes) arising in the skin and rarely in other sites.

Cell found in connective tissues containing inflammatory mediators (e.g. histamine) in basophilic granules.

Form of cell division leading to the generation of gametes (sperm or eggs).

Dark brown pigment produced by melanocytes of skin. The cytoplasmic organelles secreting melanin are called melanosomes.

Benign central nervous tissue tumor (usually) which is derived from meningeal coverings of the brain.

Undifferentiated tissue of mesodermal origin that gives rise to connective tissue including such specialized tissues as bone, cartilage, muscle and vessels.

Change in direction of differentiation by a tissue.

The process of spread of malignant cells to form colonies in distant sites (secondary deposits of cancer).

Branch of laboratory medicine involved with the identification of infective micro-organisms and the management of infection.

Non-coding regions in the genome composed of repeating sequences of bases and showing marked variation between individuals.

Cytoplasmic organelles that are the seat of aerobic respiration.

Division of a cell into two identical daughter cells.

Monoclonal antibody

Antibody produced by a clone of antibody producing cells.

Circulating white blood cell which becomes a macrophage when it leaves the bloodstream.

Alteration in the structure of a gene.

Killing lymphocyte that is neither a B cell or a T cell (null cell).

Morphological change following cell death. May be coagulative, liquefactive, caseous or fat necrosis.

A new growth that may be either benign or malignant. A malignant neoplasm is a cancer.

White blood cell also known as a polymorphonuclear leucocyte which phagocytoses bacteria. The main cell type involved in acute inflammation.

Systematic classification of disease.

Nuclear body that is the site of ribosomal RNA synthesis.

Tumor (malignant) of central nervous system derived from the oligodendrocyte (a myelin secreting cell).

Cancer gene that is an activated or mutated form of a proto-oncogene.

The study or clinical management of cancer.

Removal of dead tissue, fibrin or thrombus and its replacement by connective tissue.

The cellular or functional elements of an organ that fill the connective tissue framework or stroma.

Mechanism of evolution of a disease.

Cells with no capacity for division.

Autoimmune disease in which antibodies are directed towards the parietal cells of stomach. Parietal cells secrete acid and intrinsic factor (necessary for absorption of vitamin B₁₂). B₁₂ deficiency causes dysmaturation of red blood cells which become enlarged (megaloblastic).

Engulfment and digestion of foreign particles or cellular debris by white blood cells (neutrophils or macrophages).

Form of light microscopy that is useful for studying whole cells and living cells.

A cell derived from the B-lymphocyte that produces antibodies.

Cytoplasmic fragment derived from megakaryocytes and involved in coagulation (thrombotic aggregation) and inflammation.

A descriptive term meaning a small mushroom-like growth arising from an epithelial surface.

A histological change (sometimes described as dysplasia) associated with an increased risk of malignant transformation.

The predicted outlook for a patient with a serious disease such as cancer.

Fundamental molecule in all life-forms built of amino acids and encoded in DNA. Proteins function as enzymes, hormones, receptors and various structural filaments within cells.

A gene implicated in normal cellular division which, when mutated, becomes an oncogene.

Microscopic calcified body found in several types of neoplasm.

Thick yellow material formed of dead and dying neutrophils.

Shrinkage and increased staining intensity of nuclei seen in damaged and/or necrotic cells.

The demonstration of internal anatomy by means of X-rays and other imaging modalities.

The treatment of disease (cancer) by means of ionizing radiation.

A chemical agent which reacts with another agent (substrate) to yield a product.

Restoration of normal structure and function.

Damage to reperfused ischemic tissue caused by the formation of active oxygen species.

Variation in the structure of DNA from person to person that is demonstrated by the cutting of DNA into fragments of differing length by means of restriction enzymes.

An inherited effect observed when both copies of a gene (both alleles) are mutated.

Tumor of childhood arising in the retina of the eye.

Form of RNA from which protein synthesis occurs (translation). Ribosomes are attached to endoplasmic reticulum (rough).

Ribonucleic acid. This nucleic acid is transcribed from DNA and forms the template for the translation of a protein product.

A disorder of unknown etiology in which non-caseating granulomatous inflammation occurs in multiple tissues and organs.

Malignant neoplasm arising from connective tissue.

A population-based exercise that seeks to prevent cancer or detect it at an early and curative stage, thereby reducing the incidence of cancer-related death or morbidity within the screened community.

Gene that is linked to (i.e. resides on) a chromosome that determines gender (X chromosome in practice). In sex-linked recessive conditions, males are affected and females are carriers (usually).

State of cardiovascular collapse resulting in generalized tissue hypoperfusion and hypotension when compensatory mechanisms fail.

A blind ending track opening onto an epithelial surface and lined by granulation tissue.

Relating to cells of the body apart from germ cells.

Common form of cancer arising from skin, cervix or lung.

Cells that are capable of division when provoked but which show little mitotic activity under normal circumstances.

A system indicating the extent of spread of a cancer.

An immortal and uncommitted cell capable of differentiating into multiple cell types.

Chemical compound (for example produced by a cell) that yields a product when acted upon by a reagent.

Enzyme which reconstitutes telomeres.

Terminal portion of chromosome involved in chromosomal stability which shortens with each cell division. Implicated in aging and cancer.

Embolism made of thrombus.

Aggregation of platelets into a mass accompanied by deposition of fibrin.

Lymphoid organ in which T lymphocytes are generated.

Tissue

An aggregation of cells of one type into an organized whole.

A chemical that causes cell injury. A more specific microbiological meaning is a bacterial product that provokes injury that is accompanied by an inflammatory or immunological response. The product may be soluble (exotoxin) or associated with the bacterial cell wall (endotoxin).

Generation of protein from the RNA template.

Generation of messenger RNA from the DNA template.

Protein poor fluid collection within an extracellular site that is derived from the circulating blood.

The word literally means swelling but is used to indicate a neoplasm, either benign or malignant.

A variety of cancer gene that subserves different normal functions. When both copies are mutated or lost, the cessation of the normal function provokes malignant behavior of the cell.

Localized loss of an epithelial lining or surface.

A chronic (long-standing) disease of the large intestine associated with inflammation and ulceration.

Inflammation of vessels.

The smallest infective agent that is an obligate parasite (requires the genetic machinery of a host cell to complete its life cycle). Genetic material of a virus may be either DNA or RNA. Individual viral particles can be seen by the electron microscope but not the light microscope.

The functioning (non-mutated) form of a gene.