Contributed Commentary by Olga Colgan, PhD, Leica Biosystems
July 3, 2025 | Pathology faces a dual challenge: a shrinking workforce and a rising demand for increasingly complex tests to support precision medicine. Early screening programs and advances in biomarkers and immunotherapy mean more—and more intricate—tests per sample. At the same time, an aging population is increasing disease prevalence and case volume. With too few new professionals entering the field, the global shortage of pathologists is contributing to delays in diagnosis and treatment.
These recruitment challenges, coupled with growing diagnostic complexity, are driving organizations to explore new solutions such as digital pathology. This, in turn, not only addresses immediate workflow needs but also creates a foundation for leveraging AI. Converting glass slides into high-resolution digital images is the essential first step in developing AI tools. However, it requires more than a simple instrument swap.
Digitization Is More Than a Technical Upgrade
Digitization frees pathologists from the microscope, allowing more flexibility in how and where they work. This has become especially appealing post-COVID, as many seek better work-life balance and the option to live outside of major cities. The shift also modernizes the field, helping attract a new generation of talent.
Technological advances and clearer global regulatory pathways have made digital pathology not only viable but scalable. Yet, the biggest hurdle is often behavioral. Analogue pathology has worked well for centuries, and change can feel daunting. It’s not necessarily resistance; it’s inertia. Understandably, many institutions are interested in going digital but struggle with how to take that first step.
Transitioning to digital pathology is much like the shift from sending physical letters to sending emails. People didn’t count stamps or envelopes; they simply recognized a faster, better way to communicate. Similarly, digital transformation comes with upfront costs, but the long-term benefits are significant. In my experience, once a lab goes digital, it never goes back. It is a one-way switch.
AI: A Partner, Not a Replacement
AI and automated analysis in pathology aren’t replacements for pathologists, but tools to support their work. I see this in two main areas. First, AI can streamline laboratory workflows, such as slide quality control by automatically flagging potentially problematic slides, freeing up staff from manual review of the 80% to 90% that are likely fine. This reduces time spent on routine checks and focuses attention where it is most needed. Second, AI can augment pathologists’ reviews by assisting with tasks like screening and mitotic counting, acting as a digital safety net that flags areas of potential concern. While it offers a helpful second look, the final decision always rests with the pathologist.
Consider a car’s navigation system: it suggests the best route but doesn’t drive the car. Similarly, AI offers guidance, but the pathologist remains in control. As we move toward analyzing complex features like the tumor microenvironment and multiple biomarkers on the same slide, manual interpretation becomes increasingly difficult. This is where AI excels, delivering consistent, objective, and quantifiable insights that go beyond what the human eye can reliably achieve.
Precision Medicine and the Power of Image Analysis
Precision medicine is moving beyond single-marker analysis to examine how multiple biomarkers interact within the tumor microenvironment. While the human eye is good at recognizing patterns, it struggles with subtle color differences and complex co-expression. Even reproducible scoring of one marker like HER2 can be difficult, and the complexity increases with multiple markers.
Advanced image analysis tools can decode these intricate patterns and translate them into actionable insights. To unlock their full potential, we need digitized slides. Whole slide images become the input for these tools, making digitization not just foundational but functional. Moreover, robust AI models depend on large, high-quality image libraries. The more slides we digitize, the more powerful and accurate these tools become, creating momentum for innovation and discovery.
Computational Pathology and Democratized Care
Computational pathology, involving the digitizing of slides, rapid sharing with remote experts, and analyzing them with software, adds consistency to repetitive tasks and helps quantify biomarkers. This makes advanced diagnostics more accessible to more labs, not just specialized centers. While human expertise remains essential, digital tools support standardization and expand access. This democratization of care ensures more patients benefit from expert-level insights.
Multiplexing, Spatial Profiling, and the Next Frontier
Recent advances in immunohistochemistry and in situ hybridization have made it possible to detect multiple biomarkers on a single tissue section, moving beyond the traditional one-marker-per-slide approach. Techniques like brightfield and fluorescence multiplexing now allow for multiple markers to be visualized at once. While this produces rich, detailed images, interpreting them becomes increasingly complex, which is why automated image analysis and AI are essential for accurate and efficient evaluation.
Spatial profiling builds on this by examining not only which biomarkers are present but also where they are located within the tissue. Knowing whether markers share the same cell or microenvironment offers deeper insight into disease and treatment response. Multiplex slides, showing two or more markers on one section, reveal interactions that separate slides cannot, making spatial context vital to precision diagnostics.
The conversation around digital pathology has evolved. It’s no longer “Why should we go digital?” but “How and when can we start?” It’s a big transformation for any organization, but we know that the future of pathology is and must be digital. The question now is not if adoption will happen, but how to make it work and where to begin.
Olga Colgan, PhD has nearly two decades of experience in the digital pathology sector and is focused on how this new and disruptive technology can be leveraged to provide real benefits in both the healthcare and research domains. Before joining Leica Biosystems, she built her foundation in research, earning a BSc in Biotechnology and a PhD in Vascular Biology from Dublin City University, Ireland. She can be reached at olga.colgan@leicabiosystems.com.