Expert pathology consultation through the Internet: melanoma versus benign melanocytic tumours

Validation of diagnostic accuracy with whole-slide imaging compared with glass slide review in dermatopathology

BACKGROUND

Teledermatopathology has evolved from static images to whole slide imaging (WSI), which allows for remote viewing and manipulation of tissue sections. Previous studies of WSI in teledermatopathology predated College of American Pathologists (CAP) telepathology validation guidelines.

OBJECTIVE

We conducted a comprehensive retrospective WSI validation study of routine dermatopathology cases, adhering to CAP guidelines.

METHOD

In all, 181 consecutive cases arranged into 3 categories (inflammatory, melanocytic, nonmelanocytic proliferations) were reviewed by 3 board-certified dermatopathologists via traditional microscopy (TM) and WSI. Intraobserver (TM vs WSI), TM intraobserver and interobserver (TM vs TM), and WSI interobserver (WSI vs WSI) concordance was interpreted using a 3-tier system.

RESULTS

TM versus WSI intraobserver concordance (86.9%; 95% confidence interval [CI] 83.7-89.6) did not differ from TM versus TM intraobserver concordance (90.3%; 95% CI 86.7-93.1) or interobserver concordance (WSI: 89.9%; 95% CI 87.0-92.2, and TM: 89.5%; 95% CI 86.5-91.9). Melanocytic proliferations had the lowest TM versus WSI intraobserver concordance (75.6%; 95% CI 68.5-81.5), whereas inflammatory lesions had the highest TM versus WSI intraobserver concordance (96.1%; 95% CI 91.8-98.3). Nonmelanocytic proliferations had an intraobserver concordance of 89.1% (95% CI 83.4-93.0).

LIMITATIONS

Efficiency and other logistical WSI parameters were not evaluated.

CONCLUSION

Intraobserver and interobserver diagnostic concordance between WSI and TM was equivalent. Therefore, WSI appears to be a reliable diagnostic modality for dermatopathology.

Obstacles hindering the mainstream practice of teledermatopathology

BACKGROUND

Teledermatopathology has the potential to link underserved areas to experts across the country and assist in making quick diagnoses, which may improve health care costs and delivery. Despite these potential benefits, teledermatopathology is not used routinely for primary diagnosis in the United States.

OBJECTIVE

To assess the current status of and address the potential for improving health care by the use of teledermatolopathology for primary diagnosis.

METHODS

Current available literature and online resources were reviewed to address 3 major variables that hinder the widespread use of teledermatopathology: diagnostic accuracy, licensure requirements, and reimbursement.

RESULTS

Recent studies show similar diagnostic accuracy for this technology compared to conventional microscopy. State-to-state variation and ambiguity in laws serve as the biggest hurdles to the widespread use of teledermatopathology. More states are recognizing the importance of the implementation of specific laws regarding telemedicine. More studies are required to evaluate the systems that offer specific telemedicine licenses, in addition to those that pay for telemedicine services specifically.

LIMITATIONS

This study reviewed current legislation concerning teledermatopathology; these laws are subject to revision.

CONCLUSION

Improving diagnostic accuracy and limiting variations in policy and reimbursement may encourage more pathologists to use teledermatopathology technology.

A static-image telepathology system for dermatopathology consultation in East Africa: the Massachusetts General Hospital Experience

BACKGROUND

The histologic diagnosis of skin lesions in the developing world is complicated by the shortage of pathologists with subspecialty training in dermatopathology, limited access to ancillary diagnostic testing, and costly referrals for expert glass slide consultation in challenging cases.

OBJECTIVE

In this study we evaluate the feasibility of a static-image telepathology platform in Africa for performing accurate dermatopathology consultations.

METHODS

A static-image telepathology platform using the iPath server was utilized by referring pathologists in 4 African hospitals. Diagnostic interpretations were provided by Massachusetts General Hospital dermatopathologists at no cost. The diagnostic accuracy and interobserver correlation was evaluated.

RESULTS

The static histopathologic images were diagnostic in 22 of 29 (76%) cases. Diagnostic accuracy between static image and glass slide diagnosis in 22 cases was 91%, ranging from 86% to 95% according to years of dermatopathology subspecialty expertise. Comparison with the glass slides showed that the telepathology diagnosis was limited by inappropriate field selection in only one case. Interobserver concordance between two pathologists was high (K = 0.86) suggesting that this platform is easy to use with minimal training of both referring and consulting pathologists.

LIMITATIONS

Concordance between conventional microscopy and static image telepathology was performed in 22 of 29 cases for which glass slides were received. Interobserver concordance was performed for two pathologists.

CONCLUSION

Static-image telepathology is a feasible means of rendering diagnoses on dermatopathology cases and is a cost-effective technology for obtaining much-needed second opinions in resource-poor settings.

Feasibility and diagnostic accuracy of Internet-based dynamic telepathology between Uganda and Germany

We assessed the feasibility and diagnostic accuracy of Internet-based telepathology compared with conventional microscopic examination. A total of 96 cases from the routine workload of the Department of Pathology at the Mulago Hospital in Uganda were examined by robotic telemicroscopy via the Internet at the Fuerth Hospital in Germany. The telepathology diagnoses were compared with those of conventional microscopy. Email and Skype telephony were used to exchange clinical and diagnostic information. The reference diagnosis (gold standard) was established by consensus between two or more experienced pathologists using both conventional microscopy and telemicroscopy; immunohistochemistry was used whenever it was necessary. It took approximately 30 min for a pathologist to learn to use the telepathology system and 4–25 min to read a case remotely. Internet speed was the main limiting factor. The images were of good quality and the pathologist at the remote site was able to navigate through the slide and change the magnification as necessary. In 92 of the specimens (97%), the pathologists at the two hospitals agreed exactly about the diagnosis. Agreement overall was moderate (kappa = 0.39). The discordant diagnoses were attributed to factors related to diseases morphologically difficult to diagnose, such as soft tissue sarcomas and primitive tumours. Internet-based conferencing systems offer an inexpensive method of obtaining a primary diagnosis by telepathology and consulting on cases that require subspecialty expertise.

Teledermatology: an update

Dermatology is perhaps the most visual specialty in medicine, making it ideally suited for modern telemedicine techniques, as has been shown in a number of recent studies investigating feasibility and reliability of teledermatology. It has generally demonstrated high levels of concordance in diagnosis and management plans compared with face-to-face consultations. Teledermatology also has been used for various purposes, including triage, diagnostic and management services, and second-opinion services for primary care practitioners. It has been set up in a number of ways: (1) direct referral for primary care using images and clinical history sent to secondary care dermatology services for second opinion and for triage referrals and (2) facilitating community-based clinics led by nurses or general practitioners. Moreover, in the last years new fields in teledermatology have grown up. Teledermoscopy is a promising area for melanoma screening as well as for the diagnosis and management of equivocal pigmented skin lesions. The feasibility of mobile teledermatology and mobile teledermoscopy recently has been proven, and these new facilities have the potential to become an easy applicable tool for everyone and may open the door for a new flexible triage system for detection of skin cancer in general and melanoma in particular. The implementation of virtual slide systems for teledermatopathology has allowed avoiding the limitations imposed by conventional microphotography. Finally, web consultations in dermatology are a rather new tool that became available in the last years and teledermatologic services through the Internet offer many possibilities, including continuing medical education, on-line atlases and databases, and specific web application suited for teledermatology (ie, www.telederm.org).

Teledermatology: how to start a new teaching and diagnostic era in medicine

"Telemedicine" is defined as the use of telecommunication technologies for the exchange of medical information across distances. Applications include patient management as well as research and education. Teledermatology is a steadily growing category of telemedicine. This article presents general aspects of telemedicine, such as modes of data transmission, and practical applications with a special emphasis on their significance for teledermatology.

Feasibility and diagnostic agreement in teledermatopathology using a virtual slide system

We investigated the feasibility and diagnostic agreement of a virtual slide system (VSS) in teledermatopathology. Forty-six biopsy specimens from inflammatory skin diseases were selected and scanned with a VSS at the Research Unit of Teledermatology, Medical University of Graz, Graz, Austria. Images were stored on a virtual slide server on which a specific Web application suited for telepathology (http://telederm.org/research/dermatopath/) runs. Twelve teleconsultants from 6 different countries reviewed the 46 cases, working directly on the Web application. Telediagnoses agreed with gold standard and conventional diagnosis with an average of 73% and 74%, respectively. Complete concordance among all teleconsultants with gold standard and conventional diagnosis was found in 20% of the cases. In 10 cases in which complete clinical data were missing, the average agreement of telediagnosis with gold standard diagnosis and conventional diagnosis decreased to 65% and 66%, respectively. Only 3 of 4 cases of inflammatory skin diseases were correctly diagnosed remotely with VSS. The system that we have used, despite its usability, is not completely feasible for teledermatopathology of inflammatory skin disease. Moreover, the performance seems to have been influenced by the availability of complete clinical data and by the intrinsic difficulty of the pathology of inflammatory skin diseases.

Teledermatopathology: A Controlled Study About Diagnostic Validity and Technical Requirements for Digital Transmission

Telepathology is the practice of diagnostic histopathology performed on digital pictures. In this study, we focused on the technical requirements for achievement of a correct diagnosis on digital histopathologic images. A collection of 560 melanocytic lesions was selected from the files of the Department of Dermatology, Medical University of Graz, Austria. From each lesion one histologic slide was completely digitally scanned with a robotic microscope. Digital pictures were reviewed by 4 dermatopathologists using a presentation program, which recorded the number of image calls, applied magnifications, overall time needed, and amount of transmitted bits during the digital sign-out. One month later, the 4 microscopists had to review the corresponding slides and render a direct diagnosis on each case. Telepathologic diagnoses corresponded with the original diagnoses in a range from 90.4% to 96.4% of cases (kappa 0.80 to 0.93; P < 0.001). The median time needed for achievement of a diagnosis was 22 seconds and was significantly higher for melanomas compared with nevi. The median transmission effort for each diagnosis was 510 kilobytes after JPEG compression. Using an ISDN line with a transmission capacity of 64 kilobits/ second, this correlates to a transmission time of about 1 minute. Our results demonstrate that correct reporting on digital histopathologic images is possible with only a little time exposure. For an adequately fast transmission ISDN lines are suffcient after JPEG compression.

Clinical Application of Dynamic Telepathology in Mohs Surgery

BACKGROUND

Telepathology is an expanding technology in multiple fields for remote pathology diagnosis and consultation. The use of telepathology in Mohs surgery has been very limited.

OBJECTIVE

To describe the clinical experience of using a telepathology system for intraoperative consultations on difficult frozen sections during Mohs surgery.

MATERIALS AND METHODS

Intraoperative consultation with a dermatopathologist was obtained using a dynamic telepathology system for all questions arising on frozen sections during Mohs surgery for nonmelanoma skin cancers during a 2-year period.

RESULTS

The most common reason for consultation was to distinguish basal cell carcinoma from a benign histologic simulant on Mohs frozen sections. Other uses included determining tumor histology and distinguishing inflammation from residual tumor.

CONCLUSION

Dynamic telepathology is a useful and convenient adjunct in the Mohs surgery practice for intraoperative consultations on difficult frozen sections.

Diagnostic accuracy of second-opinion diagnoses based on still images

Second opinion of histological specimens is an important part of the daily routine in anatomic pathology practices. Today, extramural second opinion can be easily obtained by sending still images via an electronic network. The aim of this study was to examine the diagnostic accuracy of second opinion diagnosis based on still images selected from glass slides of 90 archived cases originally referred for extramural second opinion. Two pathologists together diagnosed first the still images (phase 1) and then the glass slides (phase 2). Phase 1 and phase 2 diagnoses were compared with the original second opinion diagnoses (OSODs). The pathologists achieved the same diagnostic results in phase 1 and in phase 2 measured against the OSOD, 67.8% (n = 61) and 68.9% (n = 62) complete agreement, respectively. In 29 cases in phase 1, the diagnoses were discordant with the OSOD. Three cases had incorrect benign diagnoses and 8 cases had incorrect malignant diagnoses. There were 8 false-negative diagnoses regarding malignancy, 6 false-positive diagnoses regarding malignancy, and 4 other discordant diagnoses. Eleven of the 29 discordant diagnoses could have had clinical implications. In interpreting these results, it is important to acknowledge the observer variability in diagnostic histopathology in general. In conclusion, the results support the concept of using still images to obtain second opinion diagnosis.

Teledermatology and teledermatopathology

Teledermatology is in essence an application of clinical telemedicine that deals with the practice of dermatology via the latest communication and information technology. As with other telemedicine applications, the goal is to provide the highest quality of dermatologic care more efficiently by moving patient information rather than the patient. Teledermatopathology, on the other hand, is a nonclinical telemedicine application specifically relating to diagnosis of cutaneous histologic specimens. There are numerous articles evaluating diagnostic concordance of teledermatology. However, because of a lack of a "true" gold standard, most published studies have compared diagnostic capabilities of teledermatology to our traditional face-to-face evaluations. Although the diagnostic correlation varies from study to study, most experts agree that Store and Forward and real-time video teleconferencing teledermatology is as clinically effective as a face-to-face consultation, which is less than 100% accurate. Teledermatopathology is showing similar potential, but because of the limitations on sampling error and the high cost of the alternative, robotic remote telepathology units, its acceptance into our daily practice has been delayed. This article focuses mainly on Store and Forward Teledermatology given its significant advantage and reviews the literature on teledermatology and teledermatopathology's diagnostic concordance and acceptance.

Internet teleconferencing method for telepathology consultations from lung and heart transplant patients

Current Internet-based teleconferencing techniques allow a referring pathologist to transmit real-time images from a microscope to a consultant, while maintaining a verbal conversation using Internet telephony. In our study, 50 randomly selected transbronchial biopsies from lung allograft recipients and 58 randomly selected endomyocardial biopsies from heart transplant patients were diagnosed by consultant pathologists using Internet-based teleconferencing methods. The referring pathologists acquired the real-time video images from the biopsies using a light microscope equipped with a phototube adapter and a video camera. The consultant pathologists viewed the processed images on a video monitor at 800 x 600 resolution, using a standard microcomputer equipped with Netmeeting software, and directed the referring pathologist to move the slide under the microscopy and/or change image magnification. The validity of telepathology diagnoses was assessed with kappa coefficients. Consultations were completed in 5 to 15 minutes per case. Sound transmission was unreliable, and in approximately 25% of consultations the referring pathologist needed to "call back" to reestablish verbal communication. In all but 2 transbronchial biopsies there was agreement between the original diagnosis and the diagnosis by telepathology (kappa = 0.92). In 48 of 58 endomyocardial biopsies there was concordance between the 2 diagnoses (kappa = 0.692). Only 3 out of 10 of these discrepancies were clinically significant (kappa = 0.897). Internet-based teleconferencing techniques provide effective and relatively inexpensive tools for real time telepathology consultations. The technology is probably best suited for the study of small specimens from patients that require rapid diagnosis by a consultant.

Telepathology: a diagnostic tool for the millennium?

Many developments in science have their origins in science fiction and telepathology is no exception. The concept was first illustrated in 1924 in the magazine 'Radio News'. It was not until 1980, however, that the first working telepathology system was demonstrated. Although the system was shown to work, it required special hardware, dedicated software and special microwave transmission links to be installed. Little interest was shown worldwide because of the very high cost and the inability of many people to replicate such a system. Ten years later, the personal computer (PC) was able to provide more than adequate performance at low cost for both image display quality and speed, and the development of video technology had resulted in high quality images being produced by television cameras that were now easily affordable. Microscopes were also relatively cheaper. Thus, by 1993 or 1994, all the hardware necessary to produce a telepathology system was available at reasonable cost. Telepathology can now be used for remote primary diagnosis, remote referral to a specialist pathologist, remote teaching, remote presentation of post-mortem or microscopic findings, quality assurance image circulation and feedback, and consensus diagnosis for pathological review in clinical trials. There are two residual problems. The first concerns the speed of data transmission, commonly referred to as the bandwidth. The second is that the software provided by most of the manufacturers and suppliers of these systems is not entirely suitable to the task and the systems are not interoperable. It is clear that the approach of the manufacturers is at present unlikely to produce telepathology systems which pathologists feel comfortable in using. A somewhat different approach is illustrated by the accompanying article in this issue from the Berlin group, where a relatively simple Java-based applet and the Internet are used to allow single or multiple users to view slides on a robotic microscope. This could form the basis for a truly useful system, but still needs modification for some applications.

"Virtual microscopy" and the internet as telepathology consultation tools: diagnostic accuracy in evaluating melanocytic skin lesions

The Internet offers a widely available, inexpensive tool for telepathology consultations. It allows the transfer of image and text files through electronic mail (e-mail) or file transfer protocols (FTP), using a variety of microcomputer platforms. We studied the use of the Internet and "virtual microscopy" tools for the diagnosis of 35 skin biopsies, including a variety of benign and malignant melanocytic lesions. Digitized images from these lesions were obtained at 40x and 100x optical magnification, using a high resolution digital camera (Microlumina, Leaf Systems, Southborough, MA), a light microscope with a phototube adapter and a microcomputer with a Pentium 166 MHz microprocessor. Two to four images of each case were arranged on a "canvas" to represent the majority or an entire biopsy level, using Photoshop software (Adobe Systems Inc., San Jose, CA). The images were compressed using Joint Photographers Expert Group (JPEG) format. The images were then viewed on a computer video monitor in a manner that closely resembles light microscopy, including scrolling by using the "hand tool" of Photoshop and changing magnification digitally up to 4 times without visible image degradation. The image files, ranging in size from 700 kilobytes to 2.1 megabytes (average 1.6 megabytes) were attached to e-mail messages that contained clinical information, using standard Multipurpose Internet Mail Extension (MIME) protocols and sent through the Internet, for interpretation by a dermatopathologist. The consultant could open the images from the e-mail message, using Microsoft Outlook Express (Microsoft Corp., Redmond, WA) and Photoshop software, scroll them, change magnification and render a diagnosis in a manner that closely simulates light microscopy. One hundred percent concordance was obtained between the telepathology and traditional hematoxylin and eosin slide diagnoses. The Internet and relatively inexpensive "virtual microscopy" tools offer a novel technology for dermatopathology consultations. Potential applications of this technology to pathology and technical problems posed by the use of an open, widely distributed network to share sensitive medical information are discussed.

Virtual microscopy: high resolution digital photomicrography as a tool for light microscopy simulation

Recent advances in microcomputers and high resolution digital video cameras provide pathologists the opportunity to combine precision optics with digital imaging technology and develop new educational and research tools. We review recent advances in virtual microscopy and describe techniques for viewing digital images using a microcomputer-based workstation to simulate light microscopic examination, including scanning at low power to select features of interest and zooming to increase magnification. Hardware and software components necessary to acquire digital images of histological and cytological slides, and closely simulate their examination under a light microscope are discussed. The workstation is composed of a MicroLumina digital scanning camera (Leaf Systems, Southborough, MA), light microscope (Olympus Optical Co., Lake Success, NY), Pentium (Intel Corp., Santa Clara, CA) 166 MHz microcomputer configured with 64 megabytes of random access memory (RAM), a MGA Millenium Powerdesk graphics card (Matrox Graphics, Inc., Montreal, Canada) and Photoshop software (Adobe Systems Inc., San Jose, CA) running in a Windows 95 (Microsoft Corp., Redmond, WA) environment. Images with spatial resolutions of up to 2700 x 3400 pixels in 36-bit color, can be displayed simultaneously as distinct images in a montage, or merged into a single composite image file to highlight significant features of a histological or cytological slide. These image files are saved in Joint Photographers Experts Group (JPEG) format using compression ratios of up to 80:1 without detectable visual degradation. The advantages and technical limitations of various workstation components are addressed and applications of this technology for pathology education, proficiency testing, telepathology, and database development are discussed.