Digital validation of breast biomarkers (ER, PR, AR, and HER2) in cytology specimens using three different scanners

Progression in digital pathology has yielded new opportunities for a remote work environment. We evaluated the utility of digital review of breast cancer immunohistochemical prognostic markers (IHC) using whole slide images (WSI) from formalin fixed paraffin embedded (FFPE) cytology cell block specimens (CB) using three different scanners.CB from 20 patients with breast cancer diagnosis and available IHC were included. Glass slides including 20 Hematoxylin and eosin (H&E), 20 Estrogen Receptor (ER), 20 Progesterone Receptor (PR), 16 Androgen Receptor (AR), and 20 Human Epidermal Growth Factor Receptor 2 (HER2) were scanned on 3 different scanners. Four breast pathologists reviewed the WSI and recorded their semi-quantitative scoring for each marker. Kappa concordance was defined as complete agreement between glass/digital pairs. Discordances between microscopic and digital reads were classified as a major when a clinically relevant change was seen. Minor discordances were defined as differences in scoring percentages/staining pattern that would not have resulted in a clinical implication. Scanner precision was tabulated according to the success rate of each scan on all three scanners.In total, we had 228 paired glass/digital IHC reads on all 3 scanners. There was strong concordance kappa ≥0.85 for all pathologists when comparing paired microscopic/digital reads. Strong concordance (kappa ≥0.86) was also seen when comparing reads between scanners.Twenty-three percent of the WSI required rescanning due to barcode detection failures, 14% due to tissue detection failures, and 2% due to focus issues. Scanner 1 had the best average precision of 92%. HER2 IHC had the lowest intra-scanner precision (64%) among all stains.This study is the first to address the utility of WSI in breast cancer IHC in CB and to validate its reporting using 3 different scanners. Digital images are reliable for breast IHC assessment in CB and offer similar reproducibility to microscope reads.

Ex Vivo Microscopy: A Promising Next-Generation Digital Microscopy Tool for Surgical Pathology Practice

CONTEXT.—

The rapid evolution of optical imaging modalities in recent years has opened the opportunity for ex vivo tissue imaging, which has significant implications for surgical pathology practice. These modalities have promising potential to be used as next-generation digital microscopy tools for examination of fresh tissue, with or without labeling with contrast agents.

OBJECTIVE.—

To review the literature regarding various types of ex vivo optical imaging platforms that can generate digital images for tissue recognition with potential for utilization in anatomic pathology clinical practices.

DATA SOURCES.—

Literature relevant to ex vivo tissue imaging obtained from the PubMed database.

CONCLUSIONS.—

Ex vivo imaging of tissues can be performed by using various types of optical imaging techniques. These next-generation digital microscopy tools have a promising potential for utilization in surgical pathology practice.

[Validation of Whole Slide Imaging for Primary Diagnosis of Gastrointestinal Pathology]

Whole-slide imaging (WSI) technology enables the primary diagnosis of histopathological slides. This study aimed to determine the diagnostic concordance between pathological interpretations made using WSI and those made using light microscopy (LM). For this study, 5,704 consecutive surgical pathological cases from a community hospital were included. The specimens were digitized at x40 magnification for biopsy and endoscopic resection specimens or at x20 magnification for other specimens and evaluated by 11 pathologists for diagnosis using WSI. Subsequently, the specimens were signed out using LM by 3 pathologists after 2 weeks. Diagnoses using WSI were then compared with the diagnoses made by using LM. Most (96.8%) of the 5,704 specimens were obtained from the gastrointestinal tract (2,441 biopsy specimens from the esophagogastroduodenum [42.7%], 1,678 endoscopic resection specimens from the colorectum [29.4%], 1,349 biopsy specimens from the colorectum [23.6%], 133 resected specimens from the gallbladder [2.3%], 56 endoscopic resection specimens from the stomach [0.9%], 30 resected specimens from the ap- pendix [0.5%], 14 skin biopsy specimens [0.2%], and 3 other specimens [0.1%]). The overall concordance between the diagnoses made using WSI and those made using LM was 95.1%. The major and minor dis- crepancy rates for WSI were 0.1% and 4.8%, respectively. None of the discordant cases had any clinical or prognostic implications. In conclusion, this study revealed that WSI can be used for primary diagnosis of gastrointestinal biopsy and endoscopic resection specimens. To the best of our knowledge, this is one of the studies that clearly proved that diagnosis using WSI is equivalent to diagnosis using LM. [Original].

Laboratory Automation and Middleware

The practice of surgical pathology is under constant pressure to deliver the highest quality of service, reduce errors, increase throughput, and decrease turnaround time while at the same time dealing with an aging workforce, increasing financial constraints, and economic uncertainty. Although not able to implement total laboratory automation, great progress continues to be made in workstation automation in all areas of the pathology laboratory. This report highlights the benefits and challenges of pathology automation, reviews middleware and its use to facilitate automation, and reviews the progress so far in the anatomic pathology laboratory.

Pathology Gross Photography: The Beginning of Digital Pathology

The underutilized practice of photographing anatomic pathology specimens from surgical pathology and autopsies is an invaluable benefit to patients, clinicians, pathologists, and students. Photographic documentation of clinical specimens is essential for the effective practice of pathology. When considering what specimens to photograph, all grossly evident pathology, absent yet expected pathologic features, and gross-only specimens should be thoroughly documented. Specimen preparation prior to photography includes proper lighting and background, wiping surfaces of blood, removing material such as tubes or bandages, orienting the specimen in a logical fashion, framing the specimen to fill the screen, positioning of probes, and using the right-sized scale.

Confocal microscopy with strip mosaicing for rapid imaging over large areas of excised tissue

Confocal mosaicing microscopy is a developing technology platform for imaging tumor margins directly in freshly excised tissue, without the processing required for conventional pathology. Previously, mosaicing on 12-×-12  mm² of excised skin tissue from Mohs surgery and detection of basal cell carcinoma margins was demonstrated in 9 min. Last year, we reported the feasibility of a faster approach called "strip mosaicing," which was demonstrated on a 10-×-10  mm² of tissue in 3 min. Here we describe further advances in instrumentation, software, and speed. A mechanism was also developed to flatten tissue in order to enable consistent and repeatable acquisition of images over large areas. We demonstrate mosaicing on 10-×-10  mm² of skin tissue with 1-μm lateral resolution in 90 s. A 2.5-×-3.5  cm² piece of breast tissue was scanned with 0.8-μm lateral resolution in 13 min. Rapid mosaicing of confocal images on large areas of fresh tissue potentially offers a means to perform pathology at the bedside. Imaging of tumor margins with strip mosaicing confocal microscopy may serve as an adjunct to conventional (frozen or fixed) pathology for guiding surgery.

Rapid confocal imaging of large areas of excised tissue with strip mosaicing

Imaging large areas of tissue rapidly and with high resolution may enable rapid pathology at the bedside. The limited field of view of high-resolution microscopes requires the merging of multiple images that are taken sequentially to cover a large area. This merging or mosaicing of images requires long acquisition and processing times, and produces artifacts. To reduce both time and artifacts, we developed a mosaicing method on a confocal microscope that images morphology in large areas of excised tissue with sub-cellular detail. By acquiring image strips with aspect ratios of 10:1 and higher (instead of the standard ~1:1) and "stitching" them in software, our method images 10 × 10 mm(2) area of tissue in about 3 min. This method, which we call "strip mosaicing," is currently three times as fast as our previous method.

Effectiveness of lexico-syntactic pattern matching for ontology enrichment with clinical documents

OBJECTIVE

To evaluate the effectiveness of a lexico-syntactic pattern (LSP) matching method for ontology enrichment using clinical documents.

METHODS

Two domains were separately studied using the same methodology. We used radiology documents to enrich RadLex and pathology documents to enrich National Cancer Institute Thesaurus (NCIT). Several known LSPs were used for semantic knowledge extraction. We first retrieved all sentences that contained LSPs across two large clinical repositories, and examined the frequency of the LSPs. From this set, we randomly sampled LSP instances which were examined by human judges. We used a two-step method to determine the utility of these patterns for enrichment. In the first step, domain experts annotated medically meaningful terms (MMTs) from each sentence within the LSP. In the second step, RadLex and NCIT curators evaluated how many of these MMTs could be added to the resource. To quantify the utility of this LSP method, we defined two evaluation metrics: suggestion rate (SR) and acceptance rate (AR). We used these measures to estimate the yield of concepts and relationships, for each of the two domains.

RESULTS

For NCIT, the concept SR was 24%, and the relationship SR was 65%. The concept AR was 21%, and the relationship AR was 14%. For RadLex, the concept SR was 37%, and the relationship SR was 55%. The concept AR was 11%, and the relationship AR was 44%.

CONCLUSION

The LSP matching method is an effective method for concept and concept relationship discovery in biomedical domains.

A procedure for tissue freezing and processing applicable to both intra-operative frozen section diagnosis and tissue banking in surgical pathology

Different methods for snap freezing surgical human tissue specimens exist. At pathology institutes with higher work loads, solid carbon dioxide, freezing sprays, and cryostat freezing are commonly used as coolants for diagnosing frozen tissue sections, whereas for tissue banking, liquid nitrogen or isopentane cooled with liquid nitrogen is preferred. Freezing tissues for diagnostic and research purposes are therefore often time consuming, laborious, even hazardous, and not user friendly. In tissue banks, frozen tissue samples are stored in cryovials, capsules, cryomolds, or cryocassettes. Tissues are additionally embedded using freezing media or wrapped in plastic bags or aluminum foils to prevent desiccation. The latter method aggravates enormously further tissue handling and processing. Here, we describe an isopentane-based workflow which concurrently facilitates tissue freezing and processing for both routine intra-operative frozen section and tissue banking and satisfies the qualitative demands of pathologists, cancer researchers, laboratory technicians, and tissue bankers.

A feasibility study of virtual slides in surgical pathology in China

China's huge territorial expanse and its imbalance of regional economic development have resulted in an uneven distribution of experienced pathologists. Developing telepathology for consultation is of special relevance to China. We developed a newly designed telepathology workstation, which includes a small file size of each slide, permitting easy transmission, storage, and manipulation, and a feedback function, and also evaluated its feasibility in surgical pathology in China. Four hundred cases covering a broad spectrum of surgical pathology problems were investigated in a blinded fashion by the 2 pathologists using this virtual microscope system. These cases were then randomized and re-reviewed a second time with light microscope. Diagnoses and time spent for each diagnosis were recorded for both methods. The diagnostic accuracies achieved by viewing glass slides and virtual images were 97.25% (389 of 400) and 95.5% (382 of 400) for pathologist A and 96.25% (385 of 400) and 94.75% (379 of 400) for pathologist B, respectively. There was no significant diagnostic discrepancy between the 2 methods for the 2 pathologists. The average times for viewing a virtual slide were 3.41 and 5.24 minutes for pathologists A and B, respectively, whereas the average times for viewing a glass slide were 1.16 and 3.35 minutes for pathologists A and B. There was a statistical difference between the time costs of the 2 methods. However, the slight time increase using virtual slides is less than that using dynamic telepathology and traditional consultation, and is acceptable to the pathologists. These results showed that this newly designed virtual microscope system have an acceptable diagnostic accuracy that is of practical value and may be suitable for application in China.

Why microscopy will remain a cornerstone of surgical pathology

Recent years have seen increasing predictions of the demise of conventional microscopy in patient care and investigative medicine. However, these predictions fail to recognize the power of morphologic analysis by a skilled observer. The amount of information that can be obtained from a simple H&E slide represents a windfall in terms of data quality, quantity and cost when compared to any other available technique. Moreover, the value of such interpretation is irreplaceable as we develop newer and more sophisticated technologies. Overall, it appears that reports of the death of microscopy have been greatly exaggerated.

A new device for the identification of lymph nodes at lung cancer surgery

In order to provide a precise lymph node mapping during lung cancer surgery a sterilizable plastic tray moulded in the shape of the mediastinum and lungs is presented by the author. The device makes lymph node mapping simpler, safer, quicker and methodically more structured. A positive impact is expected as a result of usage of the device from making pathologist's work easier and facilitating the flux of information on the surgeon-pathologist-oncologist-pneumonologist chain to be more disinformation-free.

Application of domestic microwave for urgent histopathology reporting: an evaluation

Rapid diagnosis of histopathological material is becoming increasingly desirable. In neuropathology, crush smear preparation and frozen section diagnosis of tissues removed during operative procedures, have remained as essential tools for rapid diagnosis. Microwave technology has been introduced into the field of tissue processing and staining in past decade. Now-a-days even automated microwave assisted rapid tissue processors are available. In our study we have analysed the use of a domestic microwave (cost approximately Rs.5000) for urgent histoprocessing (30 minutes). This could be useful in small laboratories or the ones which are in the phase of establishing the department as the procedure is much more economical than obtaining a frozen section (which requires a cryostat worth 3-6 lakhs) and the interpretation of the section obtained does not require any extra experience as these resemble the routinely processed tissue sections. The advantages and limitations of the procedure have been discussed.

A simple and economical method for the manual construction of well-aligned tissue arrays

Tissue array technology has allowed a substantial progression of studies correlating molecular and immunohistochemical findings with clinico-pathological information. Array construction presents technical difficulties and tissue arrayers are expensive, particularly for small and medium sized laboratories. We describe a simple manual method for producing well-aligned tissue arrays using a hand-made paper mold which can successfully perform immunohistochemical staining. All 200 tissue samples were collected and constructed into blocks by the paper mold. The tissue arrays were smoothly sectioned using a standard microtome and performed for a panel of immunohistochemical study with satisfactory results. This alterative method for building custom arrays could be applied in any laboratory and is both simple and economical.

Incorporation of microwave tissue processing into a routine pathology laboratory: impact on turnaround times and laboratory work patterns

AIMS

To examine the impact of microwave (MW) tissue processing on turnaround times (TATs) in a routine diagnostic laboratory.

METHODS

A retrospective review of TATs for tissue processing (specimen receipt to completion of H&E-stained section) and pathologists' report generation (receipt of stained section to validation of completed report) for small biopsies processed in a MW-histoprocessor (Milestone RHS-2, Italy) was performed and compared with similar TATs for specimens processed conventionally prior to the introduction of MW histoprocessing.

RESULTS AND CONCLUSIONS

The TAT for conventional tissue processing was almost 21 h compared with 6.5 h by MW-processing. Reporting TATs fell from 4.3 to 3.2 hours per case, respectively, largely because stained sections became available for reporting in the early afternoon instead of towards the end of the working day. If small biopsies are triaged and handled separately, the TATs can be further reduced, and in selected urgent cases, sections can be available for diagnosis within 90 minutes. The quality of MW processed sections was indistinguishable from those obtained with routine 4-hour processing. The drastic reduction in TATs signifies a new era in histopathological diagnosis in which the majority of reports can be generated within 24 hours of specimen receipt with attendant impact on patient management and hospitalisation costs.

Experience with an automated microwave-assisted rapid tissue processing method: validation of histologic quality and impact on the timeliness of diagnostic surgical pathology

We studied the effect of a fully automated microwave-assisted rapid tissue processor (RTP) on histologic examination and on the turnaround time for surgical pathology reports. A quality assurance program reviewed the histologic sections obtained by the rapid processing method for the last 3 calendar years. In addition, the histologic results from this method were compared blindly with those obtained from the conventional overnight tissue processing (CTP) method by 9 pathologists with different levels of experience. The surgical pathology turnaround times for 1 year of use of the RTP were compared with the last year for CTP. We found that the RTP reproducibly yielded histologic material comparable in quality to CTP. The turnaround time for surgical pathology reports was improved substantially, and, in particular, same-day reporting was achieved in approximately 55% of cases compared with fewer than 1% before use of the RTP. Moreover, use of the RTP enhanced safety by eliminating formalin and xylene from the procedure.

Digital photography in anatomical pathology

Digital imaging has made major inroads into the routine practice of anatomical pathology and replaces photographic prints and Kodachromes for reporting and conference purposes. More advanced systems coupled to computers allow greater versatility and speed of turnaround as well as lower costs of incorporating macroscopic and microscopic pictures into pathology reports and publications. Digital images allow transmission to remote sites via the Internet for consultation, quality assurance and educational purposes, and can be stored on and disseminated by CD-ROM. Total slide digitisation is now a reality and will replace glass slides to a large extent. Three-dimensional images of gross specimens can be assembled and posted on websites for interactive educational programmes. There are also applications in research, allowing more objective and automated quantitation of a variety of morphological and immunohistological parameters. Early reports indicate that medical vision systems are a reality and can provide for automated computer-generated histopathological diagnosis and quality assurance.

Automation of gross photography using a remote-controlled digital camera system

CONTEXT

Conventional gross photography requires a series of tedious and time-consuming steps, including taking, developing, labeling, sorting, filing, and tracking numerous photographs.

OBJECTIVE

To describe how to automate the gross photographic process by way of controlling a digital camera remotely.

DESIGN

After defining the requirements of automation regarding gross photography, a remote control board, foot switch, barcode system, and image retrieval system were devised.

SETTING

The surgical pathology laboratory of a university medical center with a commercially available megapixel digital camera.

RESULTS

The digital camera zoom and shutter were controlled remotely by a foot switch. A large portion of the gross photographic process, including specimen number labeling, image downloading, labeling, sorting, filing, and tracking, were automated. In addition, the elimination of several manual specimen-processing steps, along with not having to wait for the developing and mounting of conventional 35-mm film, reduced the entire time span required in conventional gross photography from 2 to 5 days, to a few minutes. It was also possible to review the gross images at the time of microscopic sign-out.

CONCLUSIONS

The automation of gross photography using a remote-controlled digital camera changes the conventional gross workflow markedly. We found use of a remote-controlled gross photography system to be practical, convenient, and efficient.

A comparison of routine and rapid microwave tissue processing in a surgical pathology laboratory. Quality of histologic sections and advantages of microwave processing

Rapid processing of histopathologic material is becoming increasingly desirable to fulfill the needs of clinicians treating acutely ill patients. Traditional techniques for rapid processing of paraffin-embedded tissues require 4 to 5 hours, delaying treatment for some critically ill patients and requiring additional shifts of technologists in the laboratory. Microwave processing further shortens this time, allowing even more rapid histopathologic diagnosis. Few data exist comparing quality of microwave-processed tissue with that processed by more traditional techniques. We randomly selected 158 paired specimens from 111 patients. One member of the pair was processed routinely overnight, while the other was processed by the rapid microwave technique. The slides then were compared for quality of histologic preparation in a blinded fashion by 2 pathologists. Eight routinely processed specimens were judged as suboptimal, while 6 microwave-processed specimens were judged as suboptimal and 1 was considered unsatisfactory for evaluation. In the remaining cases, the material obtained by the 2 techniques was considered of identical quality. Microwave processing considerably shortens the preparation time for permanent histologic sections without a demonstrable decrease in section quality or "readability."

Microwave technique in histopathology and its comparison with the conventional technique

125 formalin fixed human tissues from different organs and 50 fresh animal tissues were taken. Each tissue piece was divided into two. Fresh animal tissues were fixed and processed in a domestic microwave oven and formalin fixed tissue were only processed in microwave oven. Simultaneous conventional processing was also carried out. Among the fresh tissues, 34 pieces were fixed in 10% formalin and 16 were stabilized in normal saline, with microwave irradiation. For histoprocessing graded ethanol (70% and absolute) for 150 tissues and graded isopropanol (70% and absolute) for 25 tissues were used for dehydration in microwave technique. Chloroform for 95 tissues, xylene for 15 tissues and isopropanol for 65 tissues were used as clearing agent in microwave technique. Liquid paraffin was impregnating agent in all 175 cases. The oven was operated at 50% power for 10 cases and 40% power for 165 cases. Recording of temperature could not be done. Regarding fixation with formalin 80% cases gave satisfactory result, while with normal saline, only 30% cases were satisfactory. Regarding dehydration with ethanol 80% were satisfactory and with isopropanol 60% were satisfactory. Regarding clearing--both chloroform and isopropyl alcohol gave satisfactory results in 80% cases but with, xylene tissues were fragmented and brittle.

An update on "special stain" histochemistry with emphasis on automation

For nearly 100 years, pathologists have utilized "special histochemical stains" to assist in tissue-based diagnosis. As illustrated in Figures 1 and 2, histochemical stains have been used to identify infectious microorganisms (e.g., Mycobacterium tuberculosis with acid-fast bacillus (AFB) stain), to detail inflammatory stromal or structural alterations (e.g., fibrosis in liver cirrhosis with Masson trichrome), to identify microanatomic sites of disease (e.g., basement membrane in glomerulonephritis with Jones methenamine silver), to identify abnormal chemical deposits (e.g., iron in hemochromatosis with Prussian blue stain), or abnormal immune deposits (e.g., amyloid via Congo red stain). The current surgical pathology laboratory may employ a repertoire of 20 to 25 "special stains" to ensure the full diagnostic complement. While the diagnostic repertoire and the biochemical recipes for the stains are now a well-established, codified part of surgical pathology, there is an ever-moving, leading edge of new developments including new reagents, applications, and methods. This review seeks to update the reader on some of the new applications including both new reagents and methods. Particular emphasis will be placed on the recent technologic advance of automating special stains in kinetic-mode (1-4). The authors consider in turn: 1. In brief, the "news" (recent literature review) of new staining applications; 2. In greater detail, two new applications for detection of Microsporidia and Helicobacer pylori; 3. The new technologic advancement of kinetic mode automation of special stains.

Application of recent stereological tools for unbiased three-dimensional estimation of number and size of nuclei in renal cell carcinoma samples

New stereological methods have appeared in recent years that allow an unbiased and efficient estimation of quantitative characteristics of three-dimensional biological structures. The aim of this study is to apply the new stereological tools on renal tissue and investigate the changes in the number and size of nuclei in renal cell carcinomas. The simple and easy use of the disector, point-sampled intercepts and selector methods on kidney biopsies is demonstrated. Using these approaches, the mean number of nuclei per unit reference volume: NV(nucl/tis), the volume-weighted mean nuclear volume: nu V(nucl) and the number-weighted mean nuclear volume: nu N(nucl) were estimated in histological sections from 20 renal cell carcinomas. The study was performed on 10 grade 2 and 10 grade 3 renal cell carcinomas previously diagnosed by the pathologist on the basis of nuclear size increase, irregularity and nucleolar prominence. Basically, serial optical kidney sections from a 25-millimicrons thick slice were used for stereological study. The size estimations of the individual particles nu V(nucl) and nu N(nucl) obtained by the 'point-sampled intercepts' and 'selector' methods, respectively, turned out to be the most adequate parameters employed in discriminating between renal carcinoma grades (P less than or = 0.001).

The photocopier: an overlooked tool in surgical pathology

Pictorial representation of gross pathological specimens aids interpretation of many specimens in surgical pathology. The availability of such images is invaluable to subsequent review of material. Line diagrams are subjective and imprecise. Photographic recording of specimens is expensive, particularly if an instant image is required. A completely enclosed technique in which a plain paper photocopier is used to record images of gross pathological specimens is described together with appropriate applications in surgical pathology. The photocopier represents an inexpensive, rapid and reliable method of producing an acceptable permanent record of many gross specimens.

Edward Rhodes Stitt Award Lecture. Will a computer (with artificial vision) replace the surgical pathologist (or other health professionals)?

Many jobs require vision for most of the tasks performed and the discussion focuses on the nature of human visual perception. Arguments are given to support the claim that visual perception is a very complicated function of the brain. To attempt to answer whether or not artificial intelligence (AI) will ever be able to essentially do what the brain does, the history and current state of AI research is examined, with special attention to neural net research.

An image analysis workstation for the pathology laboratory

Computer-based image analysis (IA) is a technology gaining importance in diagnostic pathology. Applications of IA in pathology include DNA ploidy analysis, quantitative immunohistochemistry, three-dimensional reconstruction of tissue sections, motility studies, and chromosomal analysis. Morphometry, the quantitative measurement of size, shape, and textural features of cells and tissues, is another rapidly developing area of IA in pathology. Morphometric IA allows the objective evaluation of subtle histologic and cytologic features to yield useful diagnostic and prognostic information. Research is currently underway to develop diagnostically useful applications of morphometric IA. Several image analysis workstations designed for the pathology laboratory are currently available. However, the high cost and software inflexibility of these instruments are prohibitive to many potential users limiting the practicality of IA and hindering research. We present a relatively inexpensive pathology IA workstation assembled from commercially available hardware and software components. System features and basic image processing methods are described. A variety of practical applications for the surgical pathology laboratory are illustrated, including spatial measurements of tumors, nerve and muscle biopsy evaluation, and nuclear morphometry for classification of lymphoid effusions and hepatocellular carcinoma.

An introduction to the history of surgical pathology

Development of surgical pathology is documented, chiefly by reference to key publications in the field, beginning with the seventeenth century. Also included is a brief historical review of technical developments basic to progress in surgical pathology.