Slide Seminar Research Articles

Pathologist Computer-Aided Diagnostic Scoring of Tumor Cell Fraction: A Swiss National Study

Tumor cell fraction (TCF) estimation is a common clinical task with well-established large interobserver variability. It thus provides an ideal test bed to evaluate potential impacts of employing a tumor cell fraction computer-aided diagnostic (TCFCAD) tool to support pathologists’ evaluation. During a National Slide Seminar event, pathologists (n = 69) were asked to visually estimate TCF in 10 regions of interest (ROIs) from hematoxylin and eosin colorectal cancer images intentionally curated for diverse tissue compositions, cellularity, and stain intensities. Next, they re-evaluated the same ROIs while being provided a TCFCAD-created overlay highlighting predicted tumor vs nontumor cells, together with the corresponding TCF percentage. Participants also reported confidence levels in their assessments using a 5-tier scale, indicating no confidence to high confidence, respectively. The TCF ground truth (GT) was defined by manual cell-counting by experts. When assisted, interobserver variability significantly decreased, showing estimates converging to the GT. This improvement remained even when TCFCAD predictions deviated slightly from the GT. The standard deviation (SD) of the estimated TCF to the GT across ROIs was 9.9% vs 5.8% with TCFCAD (P < .0001). The intraclass correlation coefficient increased from 0.8 to 0.93 (95% CI, 0.65-0.93 vs 0.86-0.98), and pathologists stated feeling more confident when aided (3.67 ± 0.81 vs 4.17 ± 0.82 with the computer-aided diagnostic [CAD] tool). TCFCAD estimation support demonstrated improved scoring accuracy, interpathologist agreement, and scoring confidence. Interestingly, pathologists also expressed more willingness to use such a CAD tool at the end of the survey, highlighting the importance of training/education to increase adoption of CAD systems.

Proceedings of the 2020 Classic Examples in Toxicologic Pathology XXVII.

The histopathology slide seminar "Classic Examples in Toxicologic Pathology XXVII" was held on February 21 and 22, 2020, at the Department of Pathology at the University of Veterinary Medicine in Hannover, Germany, with joint organization by the European Society of Toxicologic Pathology. The goal of this annual seminar is to present and discuss classical and actual cases of toxicologic pathology. This article summarizes the presentations given during the seminar, including images of representative lesions. Ten actual and classical cases of toxicologic pathology, mostly induced by a test article, were presented. These included small intestine pathology and transcriptomics induced by a γ-secretase modulator, liver findings in nonhuman primates induced by gene therapy, drug-induced neutropenia in dogs, device-induced growth plate lesions, polycystic lesions in CAR/PXR double knockout mice, inner ear lesions in transgenic mice, findings in Beagle dogs induced by an inhibitor of the myeloid leukemia cell differentiation protein MCL1, findings induced by a monovalent fibroblast growth factor receptor 1 antagonist, kidney lesions induced by a mammalian target of rapamycin inhibitor in combination therapy, and findings in mutation-specific drugs.

Histoséminaire « Microbiopsie des tumeurs des tissus mous »

Histoséminaire « Microbiopsie des tumeurs des tissus mous »

The Use of Screencasts with Embedded Whole-Slide Scans and Hyperlinks to Teach Anatomic Pathology in a Supervised Digital Environment

Background: There is an increasing interest in using digitized whole-slide imaging (WSI) for routine surgical pathology diagnoses. Screencasts are digital recordings of computer screen output with advanced interactive features that allow for the preparation of videos. Screencasts that include hyperlinks to WSIs could help teach pathology residents how to become familiar with technologies that they are likely to use in their future career. Materials and Methods: Twenty screencasts were prepared with Camtasia 2.0 software (TechSmith, Okemos, MI, USA). They included clinical history, videos of chest X-rays and/or chest computed tomography images, links to WSI digitized with an Aperio Turbo AT scanner (Leica Biosystems, Buffalo Grove, IL, USA), pre- and posttests, and faculty-narrated videos of the WSI in a manner closely resembling a slide seminar and other educational materials. Screencasts were saved in a hospital network, Screencast.com, YouTube.com, and Vimeo. com. The screencasts were viewed by 12 pathology residents and fellows who made diagnoses, answered the quizzes, and took a survey with questions designed to evaluate their perception of the quality of this technology. Quiz results were automatically e-mailed to faculty. Pre- and posttest results were compared using a paired f-test. Results: Screencasts can be viewed with Windows PC and Mac operating systems and mobile devices; only videos saved in our network and screencast.com could be used to generate quizzes. Participants’ feedback was very favorable with average scores ranging from 4.5 to 4.8 (on a scale of 5). Mean posttest scores (87.0% [±21.6%]) were significantly improved over those in the pretest quizzes (48.5% [±31.2%]) (P < 0.0001). Conclusion: Screencasts with WSI that allow residents and fellows to diagnose cases using digital microscopy may prove to be a useful technology to enhance the pathology education. Future studies with larger numbers of screencasts and participants are needed to optimize various teaching strategies.

Abstract P5-09-07: Using the power of the internet to deliver breast teaching in Africa

Abstract Introduction: Delivering high quality breast teaching to African countries is of utmost importance. Our previous audit of breast cancer reporting in Africa has identified areas that would benefit from teaching and education. However, time and resource issues limit the ability to deliver teachings to a large number of African pathologists in person. Method As part of a comprehensive national in house teaching for senior trainees in Nigeria, a distant module of teaching was delivered by a team of UK pathologists using a freely available internet application. Results Distant teaching formed part of a two week residential postgraduate histopathology course that was designed for trainees preparing for their exit Histopathology exam. Sixty African pathologists attended the teaching. Previous auditing of breast cancer reporting indicated the need for education on macroscopic specimen handling, typing and grading of breast cancer. Other topics included an update on inflammatory breast cancer which has a high incidence in Africa and columnar cell lesions that are increasingly being encountered by African pathologists in the context of breast screening. A set of anonymous virtual slides were scanned and distributed to delegates before the course date. Teaching was delivered using Skype application that only required a computer with internet access at the UK and Nigeria. We utilised video-conferencing which allowed trainees to see their lecturers and vice versa. The new data sharing facility of the application allows simultaneous sharing of Power Point presentations, with annotation which facilitates interactive discussion. A slide seminar using the previously circulated virtual slides, covering areas of diagnostic challenges morphologically and by immunohistochemistry was also delivered. An approach to diagnosing these lesions was delivered with re-focussing on tumor typing and grading. Participants were able to ask questions and interact with the UK-based tutors thorough the sessions. The feedback collected from attendees was excellent. Conclusion Distant teaching using freely available internet applications is a valuable, time and cost effective method that allows sharing educational material including lectures and slide seminars in an interactive manner. It is particularly useful in delivering teaching to resource-poor countries. Citation Format: Shaaban AM, Abdulkareem F, Rotimi O. Using the power of the internet to deliver breast teaching in Africa. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-09-07.

T and NK cell neoplasms, lessons for the world from Asia

The WHO classification of lymphoid neoplasms was published in 2001, then was updated in 2008, and will be evolving in the future. This classification is based on the disease discovery and accurate description by pathologists beyond the heterogeneity in the geographical distribution of the disease entities. It is now increasingly recognized that some peculiar T and NK cell lymphomas are largely prevalent in the East Asia as mostly represented by adult T-cell leukemia/lymphoma, NK/T-cell lymphoma, intestinal T-cell lymphoma, and chronic active EBV infection. They are associated with viruses in some and generally have a broad clinicopathologic spectrum spanning from the precursor lesion to overt lymphoma, often posing the differential diagnostic problems to the pathologists. In addition, we are now facing the newly standing-up diseases. They always request us to refine the disease definitions and concepts more accurately and to innovate our therapeutic approaches. These processes simultaneously lead us to further understanding of the immunology and biology in the human beings. This slide seminar will be operated by the leading hematopathologists in Asia: Professors Koichi Ohshima, John K.C. Chan, Young-Hyeh Ko, Shih-Sung Chuang, and Tawatchai Pongpruttipan to address the new diseases, findings, and ideas since the 2008 WHO publication.

Clear cell papillary renal cell carcinoma

Clear cell papillary renal cell carcinoma is a newly described variant of renal cell carcinoma (RCC). The International Society of Urological Pathology (ISUP) Vancouver Classification of Renal Neoplasia has recently endorsed it as a distinct epithelial tumor entity and recommended the inclusion of this tumor in the ISUP Vancouver modification of the WHO 2004 histologic classification of RCCs. These tumors were originally described as a distinctive type of RCCs arising in end-stage renal disease; however, tumors with similar features can arise sporadically and have been reported in kidneys not affected by end-stage renal disease. Clear cell papillary RCCs have a distinctive morphology and immunoprofile which will be discussed in this slide seminar with case examples. Tumors with similar morphology and identical immunoprofile but also showing a characteristic smooth muscle stroma have been reported in the literature as renal angiomyodenomatous tumor (RAT). The current perspective is that both clear cell papillary RCC and RAT represent the morphologic spectrum of a single entity. Clear cell papillary RCCs lack the chromosome 3p deletion and VHL gene abnormalities, commonly seen in classic clear cell RCCs. They also lack trisomy of chromosome 7 or loss of Y chromosome, which are cytogenetic changes commonly observed in papillary RCCs. Recently clear cell papillary-like RCCs have been described in VHL patients; however these tumors lack the characteristic immunoprofile of typical clear cell papillary RCCs and frequently demonstrate chromosome 3p deletion. Clear cell papillary RCCs are typically small, biologically indolent tumors. No lymph node or distant metastasis of these tumors has been reported to date in the literature.

Bone tumours and tumour-like conditions of the head and neck and jaws

Almost all variants of malignant primary and secondary tumours of bone have been described as occurring within the head and neck and jaws. The most commonly occurring primary bone tumours affecting the jaws include osteosarcoma, Burkitt’s lymphoma and multiple myeloma, while secondary or metastatic tumours to the jaws are rare in contrast to the remainder of the skeleton. Management of patients with bone tumours and tumour-like lesions requires a team approach. Good communication between radiologist, attending head and neck surgeon and pathologist is imperative for accurate interpretation and diagnosis of these neoplasms. Pathologists who attempt to make a diagnosis of bony neoplasms without the clinical and radiographic information are at a distinct disadvantage and this is strongly discouraged. The objective of the slide seminar is to address some of the common as well as the less common bone tumours and tumour-like conditions of the head and neck and jaws.

Slide Seminar Case 7: Leydig cell tumors in rats: The application of RITA Historical Control Data

The RITA (Registry of Industrial Toxicology Animal Data) database is a proprietary database for the collection of Historical Control Data of rodent carcinogenicity studies. A number of study- and animal-related variables are collected in addition to the quality and peer reviewed histological diagnoses. Standardization of nomenclature, diagnostic criteria as well as technical procedures like tissue sampling and trimming are prerequisites for the long-term comparability of the Historical Control data. The benefits/advantages of the RITA historical control data will be shown for Leydig cell tumors in rats. In a first step, the “reliable historical control data” for a given case (Leydig cell carcinoma and its differential diagnosis of Leydig cell adenoma) will be defined by analysing the influence of strain, breeder and years of study conduct. Secondly, the historical data will be set into relation to other variables like age at necropsy, body weight or caging and feeding conditions. This example shows the value that RITA Historical Control Data can add to the interpretation of rodent carcinogenicity studies. It will also demonstrate that the analysis of RITA data may give new insights into the biology of a given neoplastic entity and discover variables with influence on its spontaneous incidence.

Breast pathology slide seminar linked to poster presentations: a new idea to make case presentations in medical conferences more interactive.

Breast pathology slide seminar linked to poster presentations: a new idea to make case presentations in medical conferences more interactive.

Records of Slide Seminar of the 11th Annual Meeting

Records of Slide Seminar of the 11th Annual Meeting

Records of Slide Seminar of the 10th Annual Meeting

Records of Slide Seminar of the 10th Annual Meeting

Experts and gold standards in dermatopathology: qualitative and quantitative analysis of the self-assessment slide seminar at the 17th colloquium of the International Society of Dermatopathology.

The diagnosis of lymphoproliferative and melanocytic skin lesions is one of the most vexing problems in dermatopathology, a problem that is compounded by the far-reaching therapeutic and psychosocial consequences of the diagnosis for both patient and physician. On the occasion of a self-assessment slide seminar held during a dermatopathology meeting, 30 unusual lymphoproliferative and melanocytic lesions, each provided with four differential diagnoses, were evaluated by "expert pathologists" and other participants ("nonexperts") of the slide seminar. The final diagnosis was pinpointed by the majority of the experts in 16 of 30 cases (56%). The group of experts returned an unanimous decision on the diagnosis in only 2 of the 30 cases (7%). In contrast to the expert group, the preferred diagnoses given by the nonexperts showed a wider range. In 20 of 30 cases (66%), the final diagnosis could only be established after consideration of clinical, histologic, immunophenotypic, and molecular features. Our findings agree with the results of recent studies indicating quite a high degree of discordance among expert pathologists. The discordance between experts and, to a higher extent, nonexperts may have some crucial consequences for dermatopathology. Full agreement on diagnosis, particularly in unusual skin lesions, cannot be achieved only by an accumulation of expertises. Instead of relying on one single finding or diagnostic procedure ("gold standard") as the main criterion upon which to base a diagnosis, the diagnoses become more reliable if based on the integration of several factors including an evaluation of clinical and histomorphologic features and immunophenotypic and molecular findings ("diagnostic elements"), particularly in the field of lymphoproliferative and melanocytic lesions. In addition, a continuous retrospective work-up of difficult or unusual cases is recommended to ensure a long-term improvement in diagnostic reliability.

Records of Slide Seminar of the 9th Annual Meeting

Records of Slide Seminar of the 9th Annual Meeting

Reproducibility of histological diagnoses and diagnostic accuracy of non palpable breast lesions

Twelve pathologists independently examined and classified a set of 25 cases of non palpable breast lesions selected from the archival files of the Pathology Department in Florence. A final consensus diagnosis was reached for all cases at a slide seminar. Individual diagnoses were first combined in 3 broad categories (benign lesion, in situ and invasive carcinoma), then compared to each other and then to the "consensus". Results show that among these 12 pathologists there was complete agreement in 14 cases. Discrepancies for the other 11 cases varied in the number of pathologists and diagnostic categories involved. Overall agreement was excellent (median kappa 0.86) but cases of potentially harmful errors were evident. The authors discuss these findings in the frame of a breast cancer screening program planning.

Neuropathology slide seminar

This slide seminar is divided into two sections -brain tumours and diseases of skeletal muscle. In the first section, fifteen tumours arising in and around the brain will be viewed and discussed. The emphasis will be on the less common (but not exceeding rare) tumours that may be found in these regions. The use of immunohistochemical stains will be mentioned, but it will be demonstrated that most brain tumours can be diagnosed using routine stains. The second section will deal with the non-tumour pathology of skeletal muscle. A practical approach to the histological diagnosis of a muscle specimen will be presented and attention will be given to frequently encountered artifacts in muscle which may give rise to diagnostic difficulties. The emphasis will be on diagnosis using ctyosections of muscle and a small number of histochemical stains.

Ninth Annual Cancer Conference and Slide Seminar

Ninth Annual Cancer Conference and Slide Seminar

Slide Seminar on Skin and Skin Appendage Tumors

Slide Seminar on Skin and Skin Appendage Tumors

Eighth Annual Cancer Conference and Slide Seminar

Eighth Annual Cancer Conference and Slide Seminar

84th Semi-annual Tumor Slide Seminar on Gynecological Pathology

84th Semi-annual Tumor Slide Seminar on Gynecological Pathology