Telepathology involves the use of telecommunication technologies to review pathology images remotely and share digital pathology images for diagnostic, research, and educational purposes. The term “telepathology” was proposed in 1986 by the American pathologist Ronald S. Weinstein when he first introduced a satellite-enabled robotic telepathology, which he patented.1 However, the adoption of telepathology for patient care has been somewhat slow—until recently.
The popularity of telepathology has spiked amidst the ongoing COVID-19 pandemic. Specifically, telepathology has played a vital role in enabling pathologists and clinicians to carry out remote diagnoses and continue providing patient care despite strict COVID-19-related social distancing regulations.2
Types of telepathology platforms used in the clinic
Static (snapshot) imaging, real-time imaging, and virtual slide microscopy systems are the three main types of telepathology platforms used in a clinical setting. Static imaging systems capture, store, and transfer digital images for remote diagnosis based on representative microscopic fields.3,4
In contrast to static imaging systems, real-time imaging systems allow pathologists to remotely evaluate entire histopathology slides. Another key advantage of real-time imaging systems is the fact that they enable pathologists to remotely operate a robotically controlled microscope to change the microscopic field, magnification, and focus. Real-time robotic microscopy using high-resolution video cameras connected to a microscope allows pathologists to remotely review tissue slides in real time.3,5
Like real-time imaging systems, virtual slide microscopy systems allow pathologists to remotely evaluate entire histopathology slides by using automated slide scanners to generate digital whole slide images. These digital images can be accessed remotely through a standalone viewer or web browser.6,7
Robotic microscopy and virtual slide telepathology have been implemented in clinical laboratories for primary histopathology diagnosis, 8 diagnosis based on frozen section specimens,9 confirmation of diagnosis by a second off-site pathologist,10,11 and toxicologic pathology.12
In addition, several international telepathology ventures have been established over the years. iPATH, developed by the University of Basel, is one of the first international telepathology platforms, bridging over 150 specialists across 32 countries. Over the last few years, numerous global telepathology networks have been established.3
Advantages of diagnostic telepathology systems
One of the main advantages of telepathology is the fact that they allow pathologists to diagnose diseases remotely. By facilitating remote access and rapid transfer of pathology images anywhere in the world, telepathology also fosters collaboration among subspecialty pathologists and consultants—which is particularly important for accurate diagnosis of difficult cases. This expansion of collaborations among specialists opens a new avenue for the establishment of improved, high-quality health care services.13,14
Another key advantage of using telepathology technologies in a clinical setting is the fact that they can enhance pathology workflow, accelerate diagnosis, and improve diagnostic accuracy. Evans et al.9 employed robotic microscopy and virtual slide telepathology to perform diagnoses based on primary frozen sections. They found that the average review time per slide for virtual slide images was four times less than that for robotic microscopy images (P < .00001). Both modalities provided a diagnostic accuracy of 98%.9 The ability of pathologists to accurately and rapidly diagnose diseases is paramount to improving patient care and treatment outcomes.
“With telepathology, cases can be reviewed simultaneously by multiple pathologists at different locations,” said Professor Jianyu Rao, Vice Chair of the Department of Pathology and Laboratory Medicine and Director of International Telepathology at the University of California at Los Angeles (UCLA). “Additionally, cases can be reviewed in a more timely manner, without having to ship slides from one place to another—which may lead to loss or damage of slides. Sometimes shipping tissues slides is impossible as some countries prohibit the export or import of biological samples, including pathology slides.”
Dunn et al.8 used a diagnostic robotic telepathology system that allowed pathologists to remotely review slides on a robotic microscope. All slides were also reviewed locally by the same pathologist on a conventional light microscope. Over a 12-year comparison period, the discordance rates of primary diagnoses were low, ranging from 0.20% to 0.45%.8
Graham et al.10 employed a virtual slide telepathology system as a part of their surgical pathology quality assurance program. They reported a complete concordance rate of 91.8% (302 of 329 cases) between on-site and off-site diagnoses; minor discrepancies were reported for 10 (3.0%) cases, and major discrepancies that would impact clinical decision making were reported for 5 (1.5%) cases. Importantly, they also found that the establishment of a quality assurance program based on virtual slide telepathology improved job satisfaction among pathologists.10
In small hospitals without full-time on-site pathologists, virtual slide telepathology for frozen intraoperative diagnosis has been reported to significantly improve patient care.15 Although setting up telepathology systems may be costly, their use may be cost-effective in the long run. A cost projection analysis by Ho et al. revealed that the 5-year total cost savings for large health care organizations implementing digital pathology systems were approximately $18 million. They also found that the primary factors responsible for these savings were improved pathologist productivity and workload distribution in clinical laboratories.16
Remaining challenges and future perspectives
Static imaging telepathology systems are relatively inexpensive and easy to use; however, their diagnostic accuracy and flexibility in use are limited. Therefore, real-time telepathology and virtual slide telepathology are emerging as the platforms of choice for clinical telepathology services.5
Although the use of real-time imaging systems and virtual slide microscopy systems can improve diagnostic accuracy, these types of telepathology systems also suffer from certain limitations. For instance, the performance of real-time imaging systems may be impacted by high network traffic in the local area networks (LANs).17
As digital slide images can be large, virtual slide telepathology generates vast amounts of data. Hence, the adoption of virtual slide telepathology in clinical laboratories raises significant IT challenges and storage concerns. Another technical concern of using telepathology technologies in clinical laboratories is the speed of transfer of digital pathology images.13
Patient privacy and data security are also key barriers limiting the clinical adoption of telepathology platforms. The use of robust firewalls and private virtual local area networks (VLANs) may help mitigate these security concerns.18
Additionally, the high cost of real-time imaging systems and virtual slide microscopy systems is another barrier hindering their clinical implementation. On the other hand, packaging and posting glass slides for consultation can also be costly and time-consuming.13
As telecommunication and digital technologies advance, many of these limitations are expected to be addressed in the near future. Despite these challenges, telepathology platforms can help leverage the expertise of subspecialty pathologists and consultants throughout the globe, enhance clinical laboratory workflow, and improve diagnosis and patient care—especially in remote, underserviced hospitals that lack in-house specialists.
- Weinstein RS, Holcomb MJ, Krupinski EA. Invention and Early History of Telepathology (1985-2000). J Pathol Inform. 2019;10:1. doi:10.4103/jpi.jpi_71_18
- Brandler TC, Warfield D, Adler E, et al. Lessons Learned From an Anatomic Pathology Department in a Large Academic Medical Center at the Epicenter of COVID-19. Acad Pathol. 2021;8:2374289521994248. doi:10.1177/2374289521994248
- Farahani N, Riben M, Evans AJ, Pantanowitz L. International Telepathology: Promises and Pitfalls. Pathobiology. 2016;83(2-3):121-126. doi:10.1159/000442390
- Farahani N, Pantanowitz L. Overview of Telepathology. Surg Pathol Clin. 2015;8(2):223-231. doi:10.1016/j.path.2015.02.018
- Bashshur RL, Krupinski EA, Weinstein RS, Dunn MR, Bashshur N. The Empirical Foundations of Telepathology: Evidence of Feasibility and Intermediate Effects. Telemed J e-health Off J Am Telemed Assoc. 2017;23(3):155-191. doi:10.1089/tmj.2016.0278
- Hanna MG, Reuter VE, Ardon O, et al. Validation of a digital pathology system including remote review during the COVID-19 pandemic. Mod Pathol. 2020;33(11):2115-2127. doi:10.1038/s41379-020-0601-5
- Aeffner F, Adissu HA, Boyle MC, et al. Digital Microscopy, Image Analysis, and Virtual Slide Repository. ILAR J. 2018;59(1):66-79. doi:10.1093/ilar/ily007
- Dunn BE, Choi H, Recla DL, Kerr SE, Wagenman BL. Robotic surgical telepathology between the Iron Mountain and Milwaukee Department of Veterans Affairs Medical Centers: a 12-year experience. Hum Pathol. 2009;40(8):1092-1099. doi:https://doi.org/10.1016/j.humpath.2009.04.007
- Evans AJ, Chetty R, Clarke BA, et al. Primary frozen section diagnosis by robotic microscopy and virtual slide telepathology: the University Health Network experience. Hum Pathol. 2009;40(8):1070-1081. doi:https://doi.org/10.1016/j.humpath.2009.04.012
- Graham AR, Bhattacharyya AK, Scott KM, et al. Virtual slide telepathology for an academic teaching hospital surgical pathology quality assurance program. Hum Pathol. 2009;40(8):1129-1136. doi:https://doi.org/10.1016/j.humpath.2009.04.008
- Massone C, Peter Soyer H, Lozzi GP, et al. Feasibility and diagnostic agreement in teledermatopathology using a virtual slide system. Hum Pathol. 2007;38(4):546-554. doi:https://doi.org/10.1016/j.humpath.2006.10.006
- Siegel G, Regelman D, Maronpot R, Rosenstock M, Hayashi S, Nyska A. Utilizing novel telepathology system in preclinical studies and peer review. J Toxicol Pathol. 2018;31(4):315-319. doi:10.1293/tox.2018-0032
- Williams S, Henricks W, Becich M, Toscano MP, Carter AB. Telepathology for Patient Care: What Am I Getting Myself Into? Adv Anat Pathol. 2010;17:130-149.
- Weinberg DS. How is telepathology being used to improve patient care? Clin Chem. 1996;42(5):831-835.
- Tsuchihashi Y, Takamatsu T, Hashimoto Y, Takashima T, Nakano K, Fujita S. Use of virtual slide system for quick frozen intra-operative telepathology diagnosis in Kyoto, Japan. Diagn Pathol. 2008;3(1):S6. doi:10.1186/1746-1596-3-S1-S6
- Ho J, Ahlers SM, Stratman C, et al. Can digital pathology result in cost savings? A financial projection for digital pathology implementation at a large integrated health care organization. J Pathol Inform. 2014;5(1):33. doi:10.4103/2153-3539.139714
- Langer SG, French T, Segovis C. TCP/IP optimization over wide area networks: implications for teleradiology. J Digit Imaging. 2011;24(2):314-321. doi:10.1007/s10278-010-9309-2
- Pantanowitz L, Sharma A, Carter AB, Kurc T, Sussman A, Saltz J. Twenty Years of Digital Pathology: An Overview of the Road Travelled, What is on the Horizon, and the Emergence of Vendor-Neutral Archives. J Pathol Inform. 2018;9:40. doi:10.4103/jpi.jpi_69_18