A pathologists' assistant (PA or PathA) is a
physician extender whose expertise lies in
gross examination
Gross processing, "grossing" or "gross pathology" is the process by which pathology specimens undergo examination with the bare eye to obtain diagnosis, diagnostic information, as well as cutting and tissue sampling in order to prepare material fo ...
of
surgical
Surgery is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery ...
specimens as well as performing hospital, medicolegal, and forensic
autopsies
An autopsy (also referred to as post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death; ...
.
Their education is analgous to
physician associates, consisting of a didactic and a clinical component and concluding in a
master's degree
A master's degree (from Latin ) is a postgraduate academic degree awarded by universities or colleges upon completion of a course of study demonstrating mastery or a high-order overview of a specific field of study or area of professional prac ...
. Certification of pathologists' assistants is through a board exam by the
American Society for Clinical Pathology
The American Society for Clinical Pathology (ASCP), formerly known as the American Society of Clinical Pathologists, is a professional association based in Chicago, Illinois, encompassing 130,000 pathologists and laboratory professionals.
Founded ...
(ASCP). In the United States, the profession is represented by the
American Association of Pathologists' Assistants (AAPA).
Pathologists' Assistants in the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
are currently only required to be licensed in three states:
Nevada
Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...
,
West Virginia
West Virginia is a mountainous U.S. state, state in the Southern United States, Southern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States.The United States Census Bureau, Census Bureau and the Association of American ...
, and
New York
New York most commonly refers to:
* New York (state), a state in the northeastern United States
* New York City, the most populous city in the United States, located in the state of New York
New York may also refer to:
Places United Kingdom
* ...
.
In most other states, the scope of PAs falls under
CLIA CLIA may refer to:
* Chemiluminescent immunoassay
* Clinical Laboratory Improvement Amendments
* Cruise Lines International Association
Cruise Lines International Association (CLIA) is a cruise line trade association. It merged with Internationa ...
high complexity testing which requires an associate degree.
General overview
Pathologists' assistants work under the indirect or direct supervision of a board certified anatomical
pathologist
Pathology is the study of disease. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatme ...
, who ultimately renders a
diagnosis
Diagnosis (: diagnoses) is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in a lot of different academic discipline, disciplines, with variations in the use of logic, analytics, and experience, to determine " ...
based on the PA's detailed gross examination and/or
tissue submission for microscopic evaluation. Requirements to become a certified pathologists' assistant include graduation from a
National Accrediting Agency for Clinical Laboratory Sciences (NAACLS) accredited
education program
Education is the transmission of knowledge and skills and the development of character traits. Formal education occurs within a structured institutional framework, such as public schools, following a curriculum. Non-formal education also fol ...
and successfully passing the
American Society for Clinical Pathology
The American Society for Clinical Pathology (ASCP), formerly known as the American Society of Clinical Pathologists, is a professional association based in Chicago, Illinois, encompassing 130,000 pathologists and laboratory professionals.
Founded ...
(ASCP) certification
exam
An examination (exam or evaluation) or test is an educational assessment intended to measure a test-taker's knowledge, skill, aptitude, physical fitness, or classification in many other topics (e.g., beliefs). A test may be administered verba ...
, which is not legally required to perform gross examinations in most states.
Some states such as West Virginia, Nevada, and New York require a license for pathologists' assistants.
All pathologists' assistants are allied health workers who need to be CLIA 88 compliant to perform these high complexity tasks with indirect/direct supervision of a pathologist.
With ongoing changes in
health care
Health care, or healthcare, is the improvement or maintenance of health via the preventive healthcare, prevention, diagnosis, therapy, treatment, wikt:amelioration, amelioration or cure of disease, illness, injury, and other disability, physic ...
, a growing population of retiring pathologista, and a decreasing number of
pathology
Pathology is the study of disease. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in the context of modern medical treatme ...
residents
In law and conflict of laws, domicile is relevant to an individual's "personal law", which includes the law that governs a person's status and their property. It is independent of a person's nationality. Although a domicile may change from time t ...
, well trained PAs are in high demand due to their extensive level of training and contribution to the overall efficiency of the pathology laboratory.
In addition to the major responsibilities outlined above, a pathologists' assistant may also perform the following tasks (for a complete list, refer to AAPA Scope of Practice
):
* Frozen sectioning for
intraoperative consultation
* Preparing tissue samples for flow
cytometry
Cytometry is the measurement of number and characteristics of cell (biology), cells. Variables that can be measured by cytometric methods include cell size, cell counting, cell count, cell morphology (shape and structure), cell cycle phase, DNA c ...
,
immunohistochemical
Immunohistochemistry is a form of immunostaining. It involves the process of selectively identifying antigens in cells and tissue, by exploiting the principle of antibodies binding specifically to antigens in biological tissues. Albert Hewett ...
(IHC) stains,
genetic testing
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...
,
microbiology
Microbiology () is the branches of science, scientific study of microorganisms, those being of unicellular organism, unicellular (single-celled), multicellular organism, multicellular (consisting of complex cells), or non-cellular life, acellula ...
culturing, and for various other laboratory evaluations
* Gross specimen
photography
Photography is the visual arts, art, application, and practice of creating images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is empl ...
* Training pathology residents, PA
fellow
A fellow is a title and form of address for distinguished, learned, or skilled individuals in academia, medicine, research, and industry. The exact meaning of the term differs in each field. In learned society, learned or professional society, p ...
s, and other pathology lab personnel (as needed)
* Fulfilling roles in
managerial
Management (or managing) is the administration of organizations, whether businesses, nonprofit organizations, or a government bodies through business administration, nonprofit management, or the political science sub-field of public administra ...
duties, instructional positions, and supervisory roles
*
Research
Research is creative and systematic work undertaken to increase the stock of knowledge. It involves the collection, organization, and analysis of evidence to increase understanding of a topic, characterized by a particular attentiveness to ...
While many PAs are employed in
hospital
A hospital is a healthcare institution providing patient treatment with specialized Medical Science, health science and auxiliary healthcare staff and medical equipment. The best-known type of hospital is the general hospital, which typically ...
s, they may also gain employment in private pathology laboratories/groups,
medical examiner
The medical examiner is an appointed official in some American jurisdictions who is trained in pathology and investigates deaths that occur under unusual or suspicious circumstances, to perform post-mortem examinations, and in some jurisdicti ...
's offices,
morgue
A morgue or mortuary (in a hospital or elsewhere) is a place used for the storage of human corpses awaiting identification (ID), removal for autopsy, respectful burial, cremation or other methods of disposal. In modern times, corpses have cu ...
s,
government
A government is the system or group of people governing an organized community, generally a State (polity), state.
In the case of its broad associative definition, government normally consists of legislature, executive (government), execu ...
or reference laboratories, or
universities
A university () is an educational institution, institution of tertiary education and research which awards academic degrees in several Discipline (academia), academic disciplines. ''University'' is derived from the Latin phrase , which roughly ...
, and may be
self-employed
Self-employment is the state of working for oneself rather than an employer. Tax authorities will generally view a person as self-employed if the person chooses to be recognised as such or if the person is generating income for which a tax return ...
and provide
contract
A contract is an agreement that specifies certain legally enforceable rights and obligations pertaining to two or more parties. A contract typically involves consent to transfer of goods, services, money, or promise to transfer any of thos ...
work.
History of profession
The idea of physician extenders was conceived in 1966 by physician-educator
Eugene A. Stead at
Duke University
Duke University is a Private university, private research university in Durham, North Carolina, United States. Founded by Methodists and Quakers in the present-day city of Trinity, North Carolina, Trinity in 1838, the school moved to Durham in 1 ...
, where the first
physician assistant
A physician assistant or physician associate (PA) is a type of non-physician practitioner. While these job titles are used internationally, there is significant variation in training and scope of practice from country to country, and sometimes be ...
program was established. Three years later, also at Duke, Chairman of Pathology, Dr. Thomas Kinney established the first pathologists’ assistant program. As of June 2025, seventeen accredited programs have been established across the
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
and
Canada
Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...
and six others are in various stages of accreditation.
Education
While curriculum may vary somewhat from program to program, all accredited pathologists' assistants programs are two-year
masters degrees that include
didactic
Didacticism is a philosophy that emphasises instructional and informative qualities in literature, art, and design. In art, design, architecture, and landscape, didacticism is a conceptual approach that is driven by the urgent need to explain.
...
and
clinical training, similar to physician associate programs. The didactic year includes education in surgical and autopsy pathology, anatomy, histology, and laboratory operations. Students are then placed in a clinical setting with affiliated hospitals and/or medical examiner's offices to learn surgical and autopsy dissection.
Pathologists' assistant programs are accredited by NAACLS and attending an accredited program is the only route to certification by the ASCP-BOC. Pathologists' assistants that have passed the ASCP certification exam use the
post-nominal letters
Post-nominal letters, also called post-nominal initials, post-nominal titles, designatory letters, or simply post-nominals, are letters placed after a person's name to indicate that the individual holds a position, an academic degree, accreditation ...
"PA(ASCP)". PA programs collectively graduate approximately 245 students a year. As of 2024, over 3000 pathologists’ assistants have been certified.
Universities offering pathologists' assistant degrees include:
#
Anderson University** ''Master of Medical Science (MMS), Pathologists’ Assistant Studies''
#
Carroll University
Carroll University is a private university in Waukesha, Wisconsin, United States. It was established in 1846 as Wisconsin's first four-year institution of higher learning. The university is affiliated with the Presbyterian Church (USA).
History ...
*** ''Master of Science in Pathologists' Assistant Studies''
#
Drexel University
Drexel University is a private university, private research university with its main campus in Philadelphia, Pennsylvania, United States. Drexel's undergraduate school was founded in 1891 by Anthony Joseph Drexel, Anthony J. Drexel, a financier ...
* ''Master of Science in Pathologists’ Assistant Studies''
#
Duke University
Duke University is a Private university, private research university in Durham, North Carolina, United States. Founded by Methodists and Quakers in the present-day city of Trinity, North Carolina, Trinity in 1838, the school moved to Durham in 1 ...
* ''Master of Health Science''
#
Loma Linda University
Loma Linda University (LLU) is a private Seventh-day Adventist health sciences university in Loma Linda, California. , the university comprises eight schools
and a Faculty of Graduate Studies. It is a part of the Seventh-day Adventist educatio ...
* ''Master’s Degree in Health Science, Pathologists’ Assistant''
#
Medical University of South Carolina
The Medical University of South Carolina (MUSC) is a public medical school in Charleston, South Carolina. It opened in 1824 as a small private college aimed at training physicians and has since established hospitals and medical facilities acros ...
*** ''Master of Science in Pathologists' Assistant Studies Program''
#
Old Dominion University EVMS* ''Master of Health Sciences, Pathologists’ Assistant''
#
Quinnipiac University
Quinnipiac University ( ) is a private university in Hamden, Connecticut, United States. The university grants undergraduate, graduate, and professional degrees. It also hosts the Quinnipiac University Polling Institute.
History
What became ...
* ''Master of Health Science''
#
Rosalind Franklin University* ''Master of Science in Pathologists' Assistant Studies''
#
Touro University** ''Master of Science''
#
Tulane University
The Tulane University of Louisiana (commonly referred to as Tulane University) is a private research university in New Orleans, Louisiana, United States. Founded as the Medical College of Louisiana in 1834 by a cohort of medical doctors, it b ...
* ''Master of Science in Anatomic Pathology''
#
University of Alberta
The University of Alberta (also known as U of A or UAlberta, ) is a public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford, the first premier of Alberta, and Henry Marshall Tory, t ...
* ''MSc with Specialization in Pathologists' Assistant''
#
University of Calgary
{{Infobox university
, name = University of Calgary
, image = University of Calgary coat of arms without motto scroll.svg
, image_size = 150px
, caption = Coat of arms
, former ...
*- ''Master of Pathologists' Assistant''
#
University of Jamestown
A university () is an institution of tertiary education and research which awards academic degrees in several academic disciplines. ''University'' is derived from the Latin phrase , which roughly means "community of teachers and scholars". Uni ...
*** ''Master of Health Science''
#
University of Maryland Baltimore* ''Master of Science in Pathology''
#
University of Tennessee Health Science Center
The University of Tennessee Health Science Center (UTHSC) is a public medical school in Memphis, Tennessee. It includes the Colleges of Health Professions, Dentistry, Graduate Health Sciences, Medicine, Nursing, and Pharmacy. Since 1911, the Uni ...
** ''Master's of Health Science (MHS) in Pathologists' Assistants''
#
University of Texas Medical Branch at Galveston
The University of Texas Medical Branch (UTMB) is a public academic health science center in Galveston, Texas, United States. It is part of the University of Texas System. UTMB includes the oldest medical school in Texas, and has about 11,000 e ...
* ''Master of Pathologists’ Assistant''
#
University of Toledo
The University of Toledo (UToledo or UT) is a Public university, public research university in Toledo, Ohio, United States. It is the northernmost campus of the University System of Ohio. The university also operates a Health Science campus, ...
*- ''Master of Science in Biomedical Science''
#
University of Toronto
The University of Toronto (UToronto or U of T) is a public university, public research university whose main campus is located on the grounds that surround Queen's Park (Toronto), Queen's Park in Toronto, Ontario, Canada. It was founded by ...
* ''Master of Health Science degree in Laboratory Medicine - Pathologists’ Assistant Field''
#
University of Washington
The University of Washington (UW and informally U-Dub or U Dub) is a public research university in Seattle, Washington, United States. Founded in 1861, the University of Washington is one of the oldest universities on the West Coast of the Uni ...
*** ''Master of Science in Anatomic Pathology''
#
University of Western Ontario
The University of Western Ontario (UWO; branded as Western University) is a Public university, public research university in London, Ontario, Canada. The main campus is located on of land, surrounded by residential neighbourhoods and the Thame ...
* ''Master of Clinical Science in Pathologists' Assistant Studies''
#
Wayne State University
Wayne State University (WSU) is a public university, public research university in Detroit, Michigan, United States. Founded in 1868, Wayne State consists of 13 schools and colleges offering approximately 375 programs. It is Michigan's third-l ...
* ''Master of Science in Pathologists' Assistant Studies''
#
West Virginia University*- ''Master of Health Science''
As of 6/13/2025, the programs above have the following status with the National Accrediting Agency for Clinical Laboratory Sciences:
, *, Accredited
, **, Serious Applicant Status
, ***, Submitted documentation to become accredited
Education and certification
Pathologists' assistants have been employed in pathology labs for over 40 years. Formal training programs slowly appeared (there were four nationwide in the late 1990s). NAACLS began accrediting PathA programs in the late 1990s, and then programs slowly continued their transitions from bachelor's to master's programs as their number increased. Prior to ASCP certification, which came about in 2005, the AAPA had a
fellow
A fellow is a title and form of address for distinguished, learned, or skilled individuals in academia, medicine, research, and industry. The exact meaning of the term differs in each field. In learned society, learned or professional society, p ...
ship status that program trained pathologists' assistants or on-the-job trained (OJT) pathologists' assistants (who could do specific coursework and three years of active employment) could join only based on passing a rigorous exam that parallels the current ASCP
certification exam
Certification is part of testing, inspection and certification and the provision by an independent body of written assurance (a certificate) that the product, service or system in question meets specific requirements. It is the formal attestatio ...
. The OJT route was eliminated at the end of 2007. The professional association uniting PAs is the
American Association of Pathologists' Assistants. Part of their duties as an association is to provide
continuing medical education
Continuing medical education (CME) is continuing education (CE) that helps those in the medical field maintain competence and learn about new and developing areas of their field. These activities may take place as live events, written publications ...
credits (CME) in order to keep members current on advances and procedures in the field that must be completed every three years in order to maintain ASCP certification.
In popular culture
The 2020 novel ''The Grave Below'' features a pathologists' assistant as a prominent character.
References
* http://www.pathassist.org
* http://naacls.org/
*
[{{Cite web , title=Pathologists' Assistant Shadowing Network , url=https://www.linkedin.com/groups/14605997/ , url-status=live , access-date=2025-06-14 , website=linkedin.com]
Pathology
Laboratory healthcare occupations