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Glossary

of Pathology Terms

A | B | C | DEF | G | H | I | J | KLMN | OP | Q | RS | T | U | VW | X | Y | Z

A

ABN Advanced Beneficiary Notice

A form that a doctor or supplier should present to a Medicare beneficiary for signature before the service is provided whenever it is believed that Medicare may not pay for the ordered service. The form documents whether: (a) the patient agrees to pay for the service if Medicare refuses OR (b) the patient declines to have the test or service performed at all. Doctors and laboratories know which tests and services may not be covered because Medicare publishes limited coverage lists. (An ABN applies only if the patient has the Original Medicare Plan, not if the patient has a Medicare-managed plan.)

adenocarcinoma
A malignant neoplasm derived from epithelium.

adjustment
Fees and payments for medical services are sometimes modified based on contractual agreements between carriers and providers.

aka
An abbreviation that means “also known as.” It is used in this glossary to indicate an alternate name for the word being defined; a synonym.

antibody
A protein molecule which binds with a specific antigen and is part of the body’s defense mechanism against disease and infection. Antibodies may also be used in diagnostic and therapeutic efforts.

antigen
A protein, carbohydrate or other molecule capable of stimulating an immune response.

aspirate
A body fluid (sampling of tissue) that has been removed from the body by negative pressure or suction. (See FNA)

assignment
A process under which Medicare pays its share of the allowed charge directly to the physician or supplier. Medicare will do this only if the physician accepts Medicare's allowed charge as payment in full.

autopsy
A postmortem examination performed by a pathologist or medical examiner/coroner in order to determine the cause of death and study pathologic changes.

B   

beneficiary aka enrollee, member
Someone who is eligible for or receiving benefits under an insurance policy or plan.

benign
The description of an illness or tumor as being relatively self-limited or non-aggressive. Opposite of malignant.

biopsy
The process of removing tissue surgically or by needle.

bladder
A gas or fluid-filled sac; example: urine bladder.

bone marrow
The soft tissue, located within the central portion of some bones, concerned with production of blood cells.

bronchial
Related to the upper respiratory tubes which carry air to and from the lungs.

brushings
A cellular sample obtained by using small bristles at the end of a handle.

C   

cell
The smallest structural unit of all plant and living organisms. Cells vary in size, shape and function. A delicate membrane encloses each cell. The genetic material of the cell is contained within the nucleus.

cell block
A specimen produced from aspirates embedded within paraffin. The liquid specimen is spun down at high revolutions per minute (centrifugation) or filtered to separate cells from liquid. The cells packed at the bottom of the test tube (cellular “plug”) is then processed in paraffin much the same as a tissue specimen.

coding
Health care services are identified and defined by specific alphanumeric abbreviations. (See CPT code and ICD-9 code)

consult/consultation
Meeting of two or more physicians to evaluate the nature and progress of disease in a particular patient and to establish diagnosis, prognosis and treatment.

core biopsy
The process of removing a specimen by means of a needle placed through the skin into the underlying tissue.

CPT code Current Procedural Terminology
A billing term for a standardized list of five-digit codes that designate the medical services delivered. The CPT codes are set, maintained and copyrighted by the American Medical Association (AMA) to describe procedures, services and supplies provided in the medical setting.

cryostat
A freezing chamber used by pathologists to prepare fresh tissue sections for immediate microscopic evaluation/diagnosis.

CSF Cerebral Spinal Fluid
The fluid which bathes the brain and spinal cord. A sample is sometimes obtained for analysis.

cyst
An abnormal sac occurring in the body which contains gas, fluid or semi-solid material.

cytogenetics
The branch of genetics concerned with the evaluation of chromosomes and their abnormalities.

cytology
The microscopic study of individual cells.

cytology, gynecologic
Cytology relating to women, primarily the genital tract as well as female reproductive physiology. (See Pap examination)

cytology, non-gynecologic
Cytological examination of exfoliated (loose) cells is useful in diagnosing pre-malignant, malignant and other disorders. Common specimens for this evaluation include CSF (cerebrospinal fluid), breast, lung, joints, bladder washings, sputum and cysts.

D   

date of service
The date the health care services were provided to the beneficiary.

decalcification
A step in the technical preparation of tissue rendering a hardened (calcified) tissue, such as bone or tooth, soft enough to cut into thin layers.

deductible
The amount of money the patient must pay toward medical bills in a calendar year before insurance begins to cover the costs of care. The dollar amount for the deductible varies according to the individual medical insurance plan. Contact your insurance carrier to determine if you have an annual deductible and how much it is.

diagnosis code (See ICD-9 code)

DNA analysis
The measurement of DNA content is an important adjunct to traditional morphology in diagnosing, assessing prognosis and determining therapy in a wide variety of malignant diseases. It is of particular prognostic value in carcinomas of the breast, bladder, colon, cervix, lung, ovary, prostate, products of conception and the non-Hodgkin’s lymphomas.

E   

effusions
The fluid which escapes from the blood vessels or lymphatic system into tissues or the body cavity.

EOB Explanation of Benefits
Statements mailed to a covered insured person and provider explaining how and why a claim was or was not paid. The Medicare version is called an EOMB (Explanation of Medical Benefits).

ERA Estrogen Receptor Assay
The evaluation of estrogen receptors in tissue used to assess treatment options or help in diagnosis.

F   

FISH Fluorescent In Situ Hybridization
A staining technique usually performed by the cytogenetics department in conjunction with chromosome analysis. Specimens tested are usually amniotic fluid, bone marrow, breast tissue and blood.

flow cytometry
An analytical technique and department using computerization and optical light beams in a standardized, small glass chamber of known volume to count and measure individual cells. Flow Cytometry is used in three broad areas: (1) in the measurement of genetic material called DNA (2) immuno-phenotyping which is the evaluation of cell surface phenotypes (antigens) using monoclonal antibodies (3) hematology (blood studies).

FNA Fine Needle Aspiration
A technique where a lesion is entered by a small needle and a cellular sample is retrieved by suction (aspiration). The sample can then be reviewed by cytology or other means. FNA is a simple and reliable cytologic test which may be used in evaluation of palpable masses. An aspirate sample is smeared on a slide, stained, and reviewed by the pathologist. In many instances, an immediate diagnosis can be rendered, saving the patient a costly and time-consuming surgical biopsy.

frozen section
A thin slice of tissue cut from a frozen specimen. Usually the pathologist joins the surgical team in the Operating Room and then prepares the frozen section in a cryostat for immediate microscopic evaluation and to offer a preliminary diagnosis. Frozen sections provide the surgeon information which may be critical to both diagnosis and treatment.

G   

guarantor
Party responsible for payment.

gross examination
The description of the physical characteristics of a specimen by manual examination before technical processing begins. The gross description is included in the pathology report. The sampling and preferred orientation of the specimen in its paraffin block is determined at this time.

H   

histochemical stain (See stains, immunohistochemistry)

histology
The science and practice that deals with preparation and microscopic study of cells in tissues and organs in relation to their anatomy and disease.

I   

ICD-9 code International Classification of Diseases, 9th Revision
An established numerical classification system is used by health care professionals to describe the diagnosis. The diagnosis code submitted by the provider explains to insurance carriers why the procedure, service, supplies or medical encounter was ordered. The diagnosis code is part of the medical claim submitted to insurance carriers for payment. Sometimes the codes provided to our laboratory are incomplete or invalid. Diagnosis coding is complicated. If an insurance carrier denies payment for a coding reason, the patient should contact the physician’s office. The office will clarify the diagnosis to our billing department.

immunocytochemistry aka ICC (See immunohistochemistry)

immunofluorescence testing
Immunofluroescent antibody testing is divided into Direct (performed on skin biopsy specimens) and Indirect (performed on serum). Specific antibodies react with specific tissue components. Immunoglobulins and/or complements (autoantibodies) become visible to the pathologist by reacting tissue sections of fresh and/or cryostat-frozen biopsies. The slide specimens are examined microscopically for specific immunofluorescence using a fluorescence microscope. Among other applications this technique may be used to evaluate a variety of autoimmune conditions such as lupus and arthritis.

immunohistochemistry aka IHC, immunocytochemistry
A special field of histology which uses antibodies to detect antigens within tissue. IHC is a laboratory technique which has dramatically improved the ability of pathologists to sub-classify benign and malignant cells and differentiate between various types of diseases.

immunophenotyping aka cell surface marker studies
The analysis of cell surface antigens is performed in the Flow Cytometry Department using monoclonal antibodies. This technique has diagnostic, prognostic and therapeutic importance for many conditions. For example, this technique is utilized to evaluate immunodeficiency diseases (hereditary and acquired) as well as to distinguish and classify lymphomas and leukemias.

insurance, health
Medical coverage by contract that guarantees payment of benefits as a result of sickness or injury. Includes insurance for losses from accident, medical expense, disability, or accidental death and dismemberment.

insurance, primary
The first medical plan that pays patient expenses, under coordination of benefits rules.

insurance, secondary
A health policy that pays costs after primary insurance, under coordination of benefits rules; any insurance that supplements primary coverage. The secondary insurance contracts reduce the patient’s direct costs.

interpretation aka “interp” on our invoice
The pathologist’s professional assessment of a case based on the attending physician’s clinical findings in conjunction with microscopic pathology. The report is sent to the ordering physician.

invoice aka statement, bill
The form sent by a health care provider charging for services rendered.

J

K

L   

lavage
The washing out of a hollow structure such as the bronchial tree.

leukemia
A neoplastic proliferation of white cells (leukocytes).

Limited Coverage Tests
Medicare limits payment for certain tests based on the frequency the test is ordered and whether or not a patient’s diagnosis meets Medicare’s insurance criteria. If Medicare may not cover the cost of the service because of limited coverage, the patient must be informed in advance of service with an opportunity to discuss patient choices and the ABN form. (See Advanced Beneficiary Notice)

M   

malignant
A property of tissues characterized by uncontrollable growth with possible invasion of normal tissues and/or metastasis.

Medicaid
A program financed jointly by the federal government and the states, that provides health coverage for mostly low income women and children as well as nursing home care for low-income elderly. Levels of funding and benefits and the portion of low-income people covered vary widely from state to state.

Medicare
The federal program providing health insurance for people aged 65 and older and for disabled people of all ages. Medicare Part A covers hospitalization and is a compulsory benefit. Medicare Part B covers outpatient services and is a voluntary service.

monoclonal antibodies
A protein, which is specific for certain antigens formed by a single clone (population) of cells. Used in the medical industry for research, diagnostics and treatments.

N   

needle biopsy (See core biopsy)

neoplasm
An abnormal tissue that grows by cellular proliferation and usually forms a distinct mass of tissue sometimes referred to as a tumor. This behavior of the cells may be either benign or malignant.

neuropathology
A subspecialty of pathology relating to the diseases of the brain, spinal cord, peripheral nerves and muscles.

O

P   

Pap examination
The microscopic evaluation of a cytology specimen for cancer detection and diagnosis, usually in reference to cervical cancer screening in women. The “Pap” technique was named after George Papanicolaou, inventor of the Pap smear, stain and examination. Papanicolaou (PAP) staining of endocervical, ectocervical and vaginal smears is an important aspect of women’s health care. Specimens in this category include traditional Pap smears as well as thin-layer (liquid-based) Pap specimens. (See cytopathology, gynecological)

pathologist
Pathologists are specialty trained physicians. They are doctors of medicine who practice chiefly in a medical laboratory setting. Pathologists serve as consultants to their clinical colleagues in the following ways: make diagnoses on anatomic tissue, guide physicians in test selection, manage medical laboratories and interpret laboratory tests. They serve as educators for the hospital staff and are referred to as “the doctor’s doctor.” Human pathology is a medical specialty requiring a medical degree and residency training in one or both branches of pathology (anatomic and clinical) or their subspecialties, as approved by the American Board of Pathology.

To become a pathologist a medical graduate must serve a five-year residency incorporating the major disciplines of anatomic and clinical pathology. Anatomic pathology encompasses surgical pathology, cytology and autopsy pathology. Clinical pathology includes all of the functions performed in the analytical work of the clinical laboratory such as hematology, chemistry, blood banking and microbiology.

Post-graduate Ph.D. degrees are available for those individuals who are interested in detailed study of disease processes and concentration on experimental pathology. Additional (subspecialty) board certifications exist for those pathologists who specialize and include such fields as: Clinical Chemistry, Cytopathology, Dermatopathology, Forensic Pathology, Hematopathology, Immunopathology, Neuropathology to name a few.

pathologists’ assistant
A Pathologists’ Assistant (PA) is an intensively trained health professional who provides anatomic pathology services under the direction and supervision of a pathologist. Pathologists’ assistants interact with pathologists in the same manner that physicians’ assistants carry out their duties under the direction of physicians in surgical and medical practice. Pathologists’ Assistants, though they do not diagnose, are an integral part of the anatomic pathology team. The PA’s contribute to the overall efficiency of the pathology practice in a cost effective manner by performing a variety of tasks, consisting primarily of gross examination of surgical pathology specimens and performance of autopsies.

The American Association of Pathologists' Assistants (AAPA) is the world's only professional organization for pathologists' assistants. Members of the AAPA have met educational and training requirements, maintain professional standards defined in the Code of Regulations and have passed the Fellowship examination.

The spectrum of ancillary activities performed by PA’s is large and influenced by different types of work settings. Following is short list of tasks that this valued member of the professional staff, qualified by their advanced academic and practical training, may perform:

  • Assist and/or perform the examination of surgical and postmortem specimens.
  • Supervise appropriate specimen accessioning and handling.
  • Describe macroscopic anatomic features.
  • Photograph specimens and microscopic slides as directed by a pathologist.
  • Dissect and prepare tissues for processing.
  • Confer with the pathologist regarding special techniques, stains and studies.

For more information: please refer to the AAPA website: www.pathologistsassistants.org

pathology, anatomic
The subspecialty of pathology that pertains to physical (gross) and microscopic study of organs, tissues and fluids removed for biopsy or during postmortem examination.

pathology, clinical
The subspecialty of pathology that deals with the theoretical and technical aspects (methods, procedures and interpretations) of automated and manual clinical testing such as chemistry, hematology, microbiology, serology, etc.

PRA Progesterone Receptor Assay
The evaluation of progesterone hormone receptors in tissues. May be used to assess diagnosis and treatment options.

premium
Amount of money paid toward the purchase of health insurance benefits.

Professional Fee
In pathology billing, the professional fee represents the pathologist’s involvement with the case:

  • Gross examination and evaluation of frozen sections (intra-operative consultation)
  • Review of all slides including consultations
  • Interpretation of the findings (including special stains that might be ordered)
  • Composition of a report for the attending clinician

Technical and Professional services are billed separately. Different providers perform these two services.

prognosis
A forecast of the probable course or outcome of a disease.

provider
An individual or institution that provides medical services (e.g. a physician, hospital or laboratory). This term should not be confused with an insurance company that "provides" insurance. Generally, the entity that provides the service is the entity that submits the bill.

Q

R

S   

sarcoma
A tumor derived from certain tissues; usually malignant.

second opinion (See consult)

slide
A thin glass plate on which a 3-4 micron thick tissue section is placed or a liquid specimen is smeared for microscopic examination.

smear
A slide preparation of a liquid or semi-liquid medical specimen to be used for microscopic study.

sputum
A specimen collected from the air passages by coughing.

stain
A laboratory technique in which chemicals are used to color and dye tissues and cells. As tools for the pathologists, many stains have specific uses for diagnosis.

stains, immunoperoxidase
These stains became available to pathologists during the 1980’s. They have revolutionized the practice of diagnostic pathology as well as opened new insights into basic research. These stains are usually monoclonal (sometimes polyclonal) antibodies, which are antibodies raised against specific proteins and amplified by cloning. The antibodies are then labeled with a marker which produces brown or red cellular colors. Depending upon the antibody used and the tissue which is stained, the pathologist may use these stains to narrow a differential diagnosis or confirm an initial impression.

stains, routine (traditional)
The routine stain for tissue sections is the H and E (Hematoxylin and Eosin). This stain has stood the test of time for nearly the entire 20th century. Hematoxylin stains tissue a deep blue while eosin stains a deep red. Depending upon the tissue, all cells are composed of a nearly infinite combination of the various hues and shades of these two stains. Most cells have a reproducible staining pattern, regardless of the tissue. For example, cell nuclei usually are deeply blue (or basophilic); squamous cells, such as those comprising the skin, are usually red (or eosinophilic).

stains, special
There are usual special stains and there are immunoperoxidase special stains. The usual special stains are based on less specific chemical reactions and may be useful to the pathologist for diagnoses.

T   

Technical Component
The technical staff of the laboratory prepares the patient’s pathology specimen for review by a pathologist. The technical process may include any or all of the following steps:

  • Inspect and describe the intact specimen (gross examination) for physical characteristics
  • Proper position of the specimen in the paraffin block
  • Fixation of the specimen in alcohol or formaldehyde to preserve the tissue
  • Decalcify to make hard bone and/or teeth soft enough to section
  • Dehydrate and infiltrate the specimen with paraffin (wax) to prevent cellular alteration
  • Embed the specimen into a small, paraffin block to keep the specimen secure
  • Cut the block into thin sections
  • Place the sections onto glass microscope slides
  • Stain the slides for professional review and interpretation
  • Prepare special stains and immunohistochemical studies

Technical and Professional services are billed separately. Different providers perform these two services.

thin-layer Pap (See cytology, gynecologic)

tumor (See neoplasm)

U

V

W   

washings
A cellular sample obtained by flushing a body area with fluid.

X

Y

Z