Grossing in Pathology: Past, Present and Future
A surgeon removes a tumour from a patient. But before an official diagnosis is confirmed, the specimen must go through a crucial step in the lab: gross examination. A pathologist, or more commonly, their assistant, inspects the tissue, ensuring that the most relevant sections are selected for microscopic analysis before the sample moves onto the next stage of the diagnosis pathway. The process of gross examination is an often overlooked, yet vital part of modern medicine.
What is grossing?
Gross examination, or more commonly ‘grossing’, is the systematic examination, description, and sectioning of surgical and biopsy specimens at the macroscopic (gross) level before histological processing. It involves careful assessment, measurement, dissection, and selection of representative tissue sections for microscopic evaluation. Grossing is a critical first step in anatomic pathology, ensuring accurate diagnoses and guiding patient management.
Where did Grossing Come From?
The concept of grossing can be traced far back in history, to times in which human beings were just beginning to understand the concepts of various illnesses through internal and external observations.
In ancient Egypt and Greece, for example, relied solely on observation. Between the 14th and 17th centuries, the Renaissance saw a rise in autopsies as a means to increase anatomical knowledge. Scholars such as Andreas Vesalius (1514–1564) performed detailed dissections during postmortem examinations, which ultimately laid the groundwork for macroscopic tissue examination.
Rudolf Virchow, who is often considered the father of modern pathology, revolutionised the concept of grossing in the 19th century. He introduced the concept of cellular pathology for the first time, which emphasised the importance of correlating macroscopic (gross) and microscopic features in diseased tissue. His teachings soon gained traction and became widespread, and as hospitals advanced over time, the mid to late 1800s saw formal specimen handling and documentation of macroscopic findings become routine.
The early 20th century saw some significant shifts towards grossing as we know it today. For example, Ferdinand Blum introduced formalin as a tissue preservative, which is still used in the present day. In this period, surgical pathology emerged for the first time, where surgical specimens were examined in depth macroscopically, before moving onto microscopic analysis. James Ewing also introduced the Frozen Section Technique in 1905, allowing for rapid intraoperative diagnosis, which further bonded the surgical and pathological processes.
The mid-20th century saw some further advances in grossing towards the specialised practice which we know today. Organisations such as the World Health Organisation (WHO), and College of American Pathologists (CAP) established guidelines for specimen handling in the 1950s and 60s, and the 1970s saw a rise in the role of pathologists’ assistants to include grossing as a standard practice, leaving pathologists with more time to focus on diagnosis.
In more recent times, many technological advances have been made to the field. Since the 1990s up until the present day, digital imaging and gross specimen photography have grown from strength to strength, becoming a routine procedure as part of the lab workflow. This field is growing and expanding, and with developing technologies such as AI for assisting grossing or 3D imaging, the future of grossing may develop even further than the process which we recognise today.
Grossing as Part of Pathology Workflows
The value and importance of grossing is undeniable. Its place as part of the pathology workflow is of extreme importance to reporting and ultimately the diagnosis of disease.
So what is the process?
Firstly, the pathologist or pathologist’s assistant examines the specimen, including all visible aspects such as size, shape, colour, weight, consistency, and abnormalities. They take photos, often on a digital macro imaging system such as PathLite+. Any findings are either recorded via digital dictation, or via built-in annotations. These are stored in a system such as PACS, meaning that when it comes time to compile a report, they are available in the Laboratory Information System (LIS).
Next, any key areas of interest, such as tumour margins, lymph nodes, or lesions, are selected, and the tissue is cut into sections to fit into labelled cassettes for processing. In order to be processed, the tissue is drained of water content, immersed in fixative, and embedded in paraffin wax for histological sectioning.
The paraffin-embedded tissue is cut into thin slices, mounted on slides, and stained with Hematoxylin & Eosin (H&E), which gives the tissue a pink/purple hue. Pathologists then examine the slides under a microscope to determine diagnoses.
In rare cases, Immunohistochemistry (IHC), molecular testing, or special stains may be ordered based on the findings from the digitised slides.
Finally, the pathology report is compiled, integrating gross and microscopic findings. The report is sent to the clinician or surgeon to guide patient treatment.
How has Grossing Technology Developed?
Grossing technology has developed alongside developments in practice. For example, Digital Grossing Workstations have evolved to include cameras, voice recognition, and barcoding for better documentation.
AI tools are also being developed to assist in tissue measurement, margin assessment, and documentation.
3D Imaging & Whole-Slide Imaging is also currently used for advanced specimen visualisation and telepathology.
Grossing: Dissected
Grossing is far more than just an initial step in the pathology workflow—it is the foundation upon which accurate diagnoses are built. By ensuring thorough specimen evaluation, selection, and documentation, grossing directly influences the quality and reliability of pathological assessments. Its meticulous process not only aids in disease classification but also plays a key role in guiding treatment decisions and improving patient outcomes.
While often overlooked, grossing remains a critical skill requiring both technical expertise and a keen eye for detail. Whether performed by a pathologist, a pathologist’s assistant, or a histotechnologist, this process is vital to ensuring the integrity of pathological diagnoses. As we look toward the future, the continued refinement of grossing protocols and emerging technologies will only enhance its efficiency, further bridging the gap between surgical specimens and definitive diagnoses.
Sources:
https://academic.oup.com/labmed/article/51/4/337/5686891?login=false
https://www.rcpath.org/international/virtual-resources/gross-examination-and-frozen-section.html
https://link.springer.com/protocol/10.1007/978-1-4939-1050-2_1
https://ornet.eu/digital-imaging-in-macro-pathology/
chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.thejcdp.com/doi/JCDP/pdf/10.5005/jp-journals-10024-220
https://link.springer.com/book/10.1007/978-3-031-72694-1?utm