Commonly Used Terms

A pathology report is filled with numerous terms and phrases that may lead to a mad scramble for a medical dictionary. Although all terms cannot be covered here, these that follow are found in the majority of pathology reports.

AJCC	Grade, Grading	Nuclei
Amphophilic	H and E	Nucleoli
Anaplasia/Anaplastic	Hemorrhage	Pathology
Apoptosis	High Power Field or HPF or hpf	Perineural Invasion
Atypia	Hydropic	Pleomorphic, Pleomorphism
Basement Membrane	Hyperchromatic	Poorly Differentiated
Basophilic, Basophilia	Immunoperoxidase Stains, IPOX	Special Stain
Cytoplasm	Inflammation	Stage, Staging
Desmoplasia, Desmoplastic	Invasion	Stroma
Differentiation	Karyrrhexis	TNM Stage
Dysplasia	Mesenchymal	Thrombosis
Endothelial	Mitotic Figure, Abnormal or Atypical Mitotic Figure, Mitotic Rate, Mitotic Index	Ultrastructural
Eosinophilic, Eosinophilia	Mucin	Undifferentiated
Epithelial	Necrosis or Necrotic	Vascular Invasion, Lymphatic Invasion, Vacular-Lymphatic Invasion
Extravasated

AJCC-American Joint Committe on Cancer prepares the cancer staging forms which are used to determine the treatment and prognosis of each cancer. See Stage.

Amphophilic-See H and E.

Anaplasia/Anaplastic-This is related to differentiation and refers to cancer cells which have a total lack of differentiation.

Apoptosis-See Apoptosis.

Atypia-A general term describing cells that vary in appearance from the normal cell. This variation may be related to inflammation or may be a cancerous or precancerous condition.

Desmoplasia, Desmoplastic-As a cancer cell invades the surrounding tissue, the host body's response attempts to keep the cancer cells in check by forming a connective tissue barrier of new collagen. This host reponse is termed desmoplasia and is a hallmark of invasion and malignancy.

Differentiation-Describes the degree or extent that cancer cells resemble normal cells. Cancer cells that closely resemble the normal cells of the tissue it is derived from are termed well-differentiated. If the cancer cells are primitive appearing or bizarre in appearance, it is termed poorly differentiated or undifferentiated.

Dysplasia-Disorderly but non-cancerous growth. It usually refers to changes that occur in epithelium. Although non-cancerous, when advanced, it is considered a significant risk factor for the development of cancer. Squamous dysplasia seen in cervical cancer and Pap smears is probably the best known example.

Extravasated-Describes blood cell components such as red or white blood cells that have escaped the confines of the blood vessel and are present within the surrounding tissue.

Grade, Grading-One component of prognosis. It is based upon the degree of differentiation of tumor cells. Low grade cancers are well differentiated while high grade cancers are poorly differentiated. Each cancer has a unique grading system and criteria. Many cancers also have a numerical grading system with grade (I) well differentiated cancers to high grade (III-IV) poorly differentiated cancers. In general, low grade cancers behave indolently while high grade cancers behave aggressively.

H and E-Stands for Hematoxylin and Eosin. This is the standard tissue stain which all pathologists and laboratories use. Each tissue will stain with varying combinations of both stains. If the tissue has more of a blue to purple hue, it is termed basophilic, preferentially staining with hematoxylin. If the tissue has a pink to red hue, it is termed eosinophilic, preferentially staining with eosin. A tissue that is neither strongly eosinophilic or basophilic is termed amphophilic.

Hemorrhage-Rupture of blood vessels leading to blood within tissue.

High Power Field or HPF or hpf-This refers to the highest magnification of a microscope objective. Most pathologists use an objective that magnifies the tissue by a factor of 400x.

Hyperchromatic-Describes the dark staining of a cell nucleus with routine H and E staining. Usually designates a cell which is actively growing such as a cancer cell.

Immunoperoxidase Stains, IPOX-See What is a Special Stain?

Inflammation-The classic description is redness, heat, pain, swelling, and loss of function. It occurs in every tissue and is present in both cancers and non-cancers. It is a protective response of the body to rid itself of the cause and consequences of cell injury.

Invasion-One of the hallmarks of a malignant tumor describing a growth pattern of cancer cells which have penetrated the basement membrane and have entered the surrounding tissue.

Karyrrhexis-Describes the dissolution and breakdown of a cell nucleus during cell death or necrosis.

Mitotic Figure, Abnormal or Atypical Mitotic Figure, Mitotic Rate, Mitotic Index-When a cell divides, it doubles its DNA or genetic material and condenses. Just before the cell divides, this condensed DNA material is visible with routine stains, and this is termed a mitotic figure. A typical mitotic figure is symmetric and well formed. Cancer cells frequently have abnormal quantities of DNA and thus form abnormal or atypical mitotic figures. The mitotic rate and index are related and are a quantative measure of the number of mitotic figures per a defined area, usually expressed in terms of a microscopic high power field (hpf or HPF). The higher the number of mitotic figures and the mitotic rate or index, the more rapidly a cell is growing, which usually correlates with aggressive growth and poorer prognosis.

Mucin-See The Cell.

Necrosis or Necrotic-Cell death.

Nuclei-See The Cell.

Nucleoli-See The Cell.

Pathology-Literally the study (logos) of suffering (pathos).

Perineural Invasion-Describes cancer cells invading in and around nerves. May be an important prognostic factor for some cancers.

Pleomorphic, Pleomorphism-Variation in size and shape. This usually refers to cancer cell size and shape.

Poorly Differentiated-See Differentiation.

Special Stains-See What is a Special Stain?

Stage, Staging-A measure of cancer prognosis. There are three components: Size (T) of the primary lesion, spread to regional lymph nodes (N), and presence or absence of metastases (M). These three components, taken together, form a TNM staging system. A higher stage is usually associated with a poorer prognosis. Each organ has a unique staging system.

Stroma-See The Cell.

TNM Stage-See Stage.

Thrombosis-This is the complex process of blood clot formation within a blood vessel involving injury to the blood vessel, altering the blood flow, and the blood clotting system. If a portion of a thrombus detaches and is carried by the blood to lodge into a distant site, this detached thrombus is called an embolus.

Ultrastructural-Describes morphological changes occuring at the cellular level which usually can only be viewed with an electron microscope.

Undifferentiated-See Differentiation.

Vascular Invasion, Lymphatic Invasion, Vacular-Lymphatic Invasion-Decribes cancer cells invading into and present within the blood or lymphatic vessels. May be an important prognostic factor for some cancers.