A whole-slide imaging based workflow reduces the reading time of pathologists.

Even though entirely digitized microscopic tissue sections (whole slide images, WSIs) are increasingly being used in histopathology diagnostics, little data is still available on the effect of this technique on pathologists' reading time. This study aimed to compare the time required to perform the microscopic assessment by pathologists between a conventional workflow (an optical microscope) and digitized WSIs. WSI was used in primary diagnostics at the Laboratory for Pathology Eastern Netherlands for several years (LabPON, Hengelo, The Netherlands). Cases were read either in a traditional workflow, with the pathologist recording the time required for diagnostics and reporting, or entirely digitally. Reading times were extracted from image management system log files, and the digitized workflow was fully integrated into the laboratory information system. The digital workflow saved time in the majority of case categories, with prostate biopsies saving the most (68% time gain). Taking into account case distribution, the digital workflow produced an average gain of 12.3%. Using WSI instead of conventional microscopy significantly reduces pathologists' reading times. Pathologists must work in a fully integrated environment to fully reap the benefits of a digital workflow.

Evaluating the benefits of digital pathology implementation: time savings in laboratory logistics.

BACKGROUND: The benefits of digital pathology for workflow improvement and thereby cost savings in pathology, at least partly outweighing investment costs, are being increasingly recognised. Successful implementations in a variety of scenarios have started to demonstrate the cost benefits of digital pathology for both research and routine diagnosis, contributing to a sound business case encouraging further adoption. To further support new adopters, there is still a need for detailed assessment of the impact that this technology has on the relevant pathology workflows, with an emphasis on time-saving. AIMS: To assess the impact of digital pathology adoption on logistic laboratory tasks (i.e. not including pathologists' time for diagnosis-making) in the Laboratorium Pathologie Oost Nederland, a large regional pathology laboratory in The Netherlands. METHODS AND RESULTS: To quantify the benefits of digitisation, we analysed the differences between the traditional analogue and new digital workflows, carried out detailed measurements of all relevant steps in key analogue and digital processes, and compared the time spent. We modelled and assessed the logistic savings in five workflows: (i) routine diagnosis; (ii) multidisciplinary meeting; (iii) external revision requests; (iv) extra stainings; and (v) external consultation. On average, >19 working hours were saved on a typical day by working digitally, with the highest savings in routine diagnosis and multidisciplinary meeting workflows. CONCLUSIONS: By working digitally, a significant amount of time could be saved in a large regional pathology laboratory with a typical case mix. We also present the data in each workflow per task and concrete logistic steps to allow extrapolation to the context and case mix of other laboratories.

Validation of a whole-slide image-based teleconsultation network.

AIMS: Most validation studies on digital pathology diagnostics have been performed in single institutes. Because rapid consultation on cases with extramural experts is one of the most important uses for digital pathology laboratory networks, the aim of this study was to validate a whole-slide image-based teleconsultation network between three independent laboratories. METHODS AND RESULTS: Each laboratory contributed 30 biopsies and/or excisions, totalling 90 specimens (776 slides) of varying difficulty and covering a wide variety of organs and subspecialties. All slides were scanned centrally at ×40 scanning magnification and uploaded, and subsequently assessed digitally by 16 pathologists using the same image management system and viewer. Each laboratory was excluded from digital assessment of their own cases. Concordance rates between the two diagnostic modalities (light microscopic versus digital) were compared. Loading speed of the images, zooming latency and focus quality were scored. Leaving out eight minor discrepancies without any clinical significance, the concordance rate between remote digital and original microscopic diagnoses was 97.8%. The two cases with a major discordance (for which the light microscopic diagnoses were deemed to be the better ones) resulted from a different interpretation of diagnostic criteria in one case and an image quality issue in the other case. Average scores for loading speed of the images, zooming latency and focus quality were 2.37 (on a scale up to 3), 2.39 (scale up to 3) and 3.06 (scale up to 4), respectively. CONCLUSIONS: This validation study demonstrates the suitability of a teleconsultation network for remote digital consultation using whole-slide images. Such networks may contribute to faster revision and consultation in pathology while maintaining diagnostic standards.

Degeneration and atherosclerosis inducing increased deposition of type IIA secretory phospholipase A2, C-reactive protein and complement in aortic valves cause neutrophilic granulocyte influx.

BACKGROUND AND AIM OF THE STUDY: Recent studies have indicated that atherosclerosis-like changes are involved in the pathogenesis of aortic valve stenosis. Increased blood and valve tissue levels of C-reactive protein (CRP) have been reported in patients with aortic valve disease, although the different pathological conditions involved were not analyzed. The study aim was to monitor the deposition of CRP, its activator sPLA2-IIA and its effector complement, and the subsequent influx of neutrophilic granulocytes in degenerative and atherosclerotic aortic valves. METHODS: Human tricuspid aortic valves (n = 57) obtained at autopsy included five control valves, 36 aortic valves with atherosclerotic changes, and 16 with degenerative changes. All valves were analyzed immunohistochemically for the presence of sPLA2-IIA, CRP, C3d and MPO (to detect neutrophilic granulocytes), and subsequently quantified using computer-assisted morphometry. RESULTS: In aortic valves with degeneration, the areas of sPLA2-IIA, CRP and complement deposition were all significantly increased compared to control valves. These mediators were even more extensively deposited in atherosclerotically changed aortic valves. The increased deposition of these mediators coincided with a significant increase of neutrophilic granulocytes in atherosclerotic and degenerated aortic valves, compared to control valves. CONCLUSION: The study results indicate that sPLA2-IIA, CRP, and C3d are significantly more activated in atherosclerotic aortic valves compared to degeneratively changed aortic valves. A significant increase was also identified in neutrophilic granulocytes in non-infectious, diseased valves (atherosclerosis and degeneration).

Impact of rescanning and normalization on convolutional neural network performance in multi-center, whole-slide classification of prostate cancer.

Algorithms can improve the objectivity and efficiency of histopathologic slide analysis. In this paper, we investigated the impact of scanning systems (scanners) and cycle-GAN-based normalization on algorithm performance, by comparing different deep learning models to automatically detect prostate cancer in whole-slide images. Specifically, we compare U-Net, DenseNet and EfficientNet. Models were developed on a multi-center cohort with 582 WSIs and subsequently evaluated on two independent test sets including 85 and 50 WSIs, respectively, to show the robustness of the proposed method to differing staining protocols and scanner types. We also investigated the application of normalization as a pre-processing step by two techniques, the whole-slide image color standardizer (WSICS) algorithm, and a cycle-GAN based method. For the two independent datasets we obtained an AUC of 0.92 and 0.83 respectively. After rescanning the AUC improves to 0.91/0.88 and after style normalization to 0.98/0.97. In the future our algorithm could be used to automatically pre-screen prostate biopsies to alleviate the workload of pathologists.

A 37-Year-Old Woman With Recurrent Hemoptysis.

CASE PRESENTATION: A 37-year-old woman presented with a 2-month history of recurrent hemoptysis and coughing. Her symptoms started 2 months after the delivery of her third child. In total, she endured four episodes of hemoptysis. All pregnancies were induced by intracytoplasmic sperm injections. She lacked a pulmonary or smoking history and had no history of foreign body aspiration or intubation. There was no dyspnea, dysphagia, fever, or chest pain, and the patient did not complain of purulent sputum. She currently did not use medication and was generally in good health.

Computer aided quantification of intratumoral stroma yields an independent prognosticator in rectal cancer.

PURPOSE: Tumor-stroma ratio (TSR) serves as an independent prognostic factor in colorectal cancer and other solid malignancies. The recent introduction of digital pathology in routine tissue diagnostics holds opportunities for automated TSR analysis. We investigated the potential of computer-aided quantification of intratumoral stroma in rectal cancer whole-slide images. METHODS: Histological slides from 129 rectal adenocarcinoma patients were analyzed by two experts who selected a suitable stroma hot-spot and visually assessed TSR. A semi-automatic method based on deep learning was trained to segment all relevant tissue types in rectal cancer histology and subsequently applied to the hot-spots provided by the experts. Patients were assigned to a 'stroma-high' or 'stroma-low' group by both TSR methods (visual and automated). This allowed for prognostic comparison between the two methods in terms of disease-specific and disease-free survival times. RESULTS: With stroma-low as baseline, automated TSR was found to be prognostic independent of age, gender, pT-stage, lymph node status, tumor grade, and whether adjuvant therapy was given, both for disease-specific survival (hazard ratio = 2.48 (95% confidence interval 1.29-4.78)) and for disease-free survival (hazard ratio = 2.05 (95% confidence interval 1.11-3.78)). Visually assessed TSR did not serve as an independent prognostic factor in multivariate analysis. CONCLUSIONS: This work shows that TSR is an independent prognosticator in rectal cancer when assessed automatically in user-provided stroma hot-spots. The deep learning-based technology presented here may be a significant aid to pathologists in routine diagnostics.

The Importance of eSlide Macro Images for Primary Diagnosis with Whole Slide Imaging.

INTRODUCTION: A whole slide image (WSI) is typically comprised of a macro image (low-power snapshot of the entire glass slide) and stacked tiles in a pyramid structure (with the lowest resolution thumbnail at the top). The macro image shows the label and all pieces of tissue on the slide. Many whole slide scanner vendors do not readily show the macro overview to pathologists. We demonstrate that failure to do so may result in a serious misdiagnosis. MATERIALS AND METHODS: Various examples of errors were accumulated that occurred during the digitization of glass slides where the virtual slide differed from the macro image of the original glass slide. Such examples were retrieved from pathology laboratories using different types of scanners in the USA, Canada, Europe, and Asia. RESULTS: The reasons for image errors were categorized into technical problems (e.g., automatic tissue finder failure, image mismatches, and poor scan coverage) and human operator mistakes (e.g., improper manual region of interest selection). These errors were all detected because they were highlighted in the macro image. CONCLUSION: Our experience indicates that WSI can be subject to inadvertent errors related to glitches in scanning slides, corrupt images, or mistakes made by humans when scanning slides. Displaying the macro image that accompanies WSIs is critical from a quality control perspective in digital pathology practice as this can help detect these serious image-related problems and avoid compromised diagnoses.

1399 H&E-stained sentinel lymph node sections of breast cancer patients: the CAMELYON dataset.

Background: The presence of lymph node metastases is one of the most important factors in breast cancer prognosis. The most common way to assess regional lymph node status is the sentinel lymph node procedure. The sentinel lymph node is the most likely lymph node to contain metastasized cancer cells and is excised, histopathologically processed, and examined by a pathologist. This tedious examination process is time-consuming and can lead to small metastases being missed. However, recent advances in whole-slide imaging and machine learning have opened an avenue for analysis of digitized lymph node sections with computer algorithms. For example, convolutional neural networks, a type of machine-learning algorithm, can be used to automatically detect cancer metastases in lymph nodes with high accuracy. To train machine-learning models, large, well-curated datasets are needed. Results: We released a dataset of 1,399 annotated whole-slide images (WSIs) of lymph nodes, both with and without metastases, in 3 terabytes of data in the context of the CAMELYON16 and CAMELYON17 Grand Challenges. Slides were collected from five medical centers to cover a broad range of image appearance and staining variations. Each WSI has a slide-level label indicating whether it contains no metastases, macro-metastases, micro-metastases, or isolated tumor cells. Furthermore, for 209 WSIs, detailed hand-drawn contours for all metastases are provided. Last, open-source software tools to visualize and interact with the data have been made available. Conclusions: A unique dataset of annotated, whole-slide digital histopathology images has been provided with high potential for re-use.

Tumor-stroma ratio as prognostic factor for survival in rectal adenocarcinoma: A retrospective cohort study.

AIM: To evaluate the prognostic value of the tumor-stroma ratio (TSR) in rectal cancer. METHODS: TSR was determined on hematoxylin and eosin stained histological sections of 154 patients treated for rectal adenocarcinoma without prior neoadjuvant treatment in the period 1996-2006 by two observers to assess reproducibility. Patients were categorized into three categories: TSR-high [carcinoma percentage (CP) ≥ 70%], TSR-intermediate (CP 40%, 50% and 60%) and TSR-low (CP ≤ 30%). The relation between categorized TSR and survival was analyzed using Cox proportional hazards model. RESULTS: Thirty-six (23.4%) patients were scored as TSR-low, 70 (45.4%) as TSR-intermediate and 48 (31.2%) as TSR-high. TSR had a good interobserver agreement (κ = 0.724, concordance 82.5%). Overall survival (OS) and disease free survival (DFS) were significantly better for patients with a high TSR (P = 0.01 and P = 0.02, respectively). A similar association existed for disease specific survival (P = 0.06). In multivariate analysis, patients without lymph node metastasis and an intermediate TSR had a higher risk of dying from rectal cancer (HR = 5.27, 95%CI: 1.54-18.10), compared to lymph node metastasis negative patients with a high TSR. This group also had a worse DFS (HR = 6.41, 95%CI: 1.84-22.28). An identical association was seen for OS. These relations were not seen in lymph node metastasis positive patients. CONCLUSION: The TSR has potential as a prognostic factor for survival in surgically treated rectal cancer patients, especially in lymph node negative cases.

Increased accumulation of the glycoxidation product Nepsilon-(carboxymethyl)lysine in hearts of diabetic patients: generation and characterisation of a monoclonal anti-CML antibody.

Heart failure is a condition closely linked to diabetes. Hyperglycaemia amplifies the generation of a major advanced glycation end product Nepsilon-(carboxymethyl)lysine (CML), which has been associated with the development of vascular and inflammatory complications. An increased accumulation of CML in hearts of diabetic patients may be one of the mechanisms related to the high risk of heart failure. Therefore, we investigated the localization of CML in diabetic hearts. To investigate the presence and accumulation of CML in tissues, a monoclonal anti-CML antibody was generated and characterised. With this novel monoclonal antibody against CML, the localization of CML was investigated by immunohistochemistry, in heart tissue of controls (n = 9) and heart tissue of diabetic patients (n = 8) without signs of inflammation or infarction. In addition, in the same subjects we studied the presence of CML in renal and lung tissues. CML staining was approximately sixfold higher in hearts from diabetic patients as compared to control hearts (2.0 +/- 0.3 and 0.3 +/- 0.2 A.U., respectively, P < 0.01). CML deposition was localized in the small intramyocardial arteries in endothelial cells and smooth muscle cells, but not in cardiomyocytes. These arteries did not show morphological abnormalities. The intensity of staining between arteries at the epicardial, midcardial and endocardial side did not vary significantly within patients. In renal tissues, CML staining was most prominent in tubules and in atherosclerotic vessels, without differences in intensity between controls and diabetic patients. In non-infected lungs, no CML was detected. In conclusion, CML adducts are abundantly present in small intramyocardial arteries in the heart tissue of diabetic patients. The accumulation of CML in diabetic hearts may contribute to the increased risk of heart failure in hyperglycaemia.

Secretory type II phospholipase A(2) binds to ischemic myocardium during myocardial infarction in humans.

OBJECTIVE: An increase of circulating secretory Phospholipase A(2) (sPLA(2)) is a risk factor for coronary artery disease. We hypothesized that this reflects participation of sPLA(2) in local inflammatory reactions ensuing in ischemic myocardium. Therefore, we studied the course of circulating sPLA(2), in patients with acute myocardial infarction (AMI) or unstable angina pectoris (UAP), and investigated the presence of sPLA(2) in infarcted myocardial tissue. METHODS: Plasma samples of 107 patients with AMI or UAP, collected on admission and at varying intervals thereafter, were tested for the presence of sPLA(2) and C-reactive protein (CRP). Cumulative release values of these parameters were calculated, which allowed for comparison of the results rearranged in time according to the onset of symptoms. By immunohistochemistry we studied the presence of sPLA(2) and CRP in myocardial tissue of 30 patients who died subsequent to AMI. RESULTS: Levels of sPLA(2) became elevated during the disease course in 66 of the 87 patients with AMI, and were higher than those of the patients with UAP of whom 8 of the 20 had elevated levels. By immunohistochemistry sPLA(2) was found to be localized in the infarcted myocardium, particularly in its borderzone, from 12 h after the onset of AMI. Positive staining for sPLA(2) was more extensive than that for CRP. CONCLUSIONS: The localization pattern of sPLA(2) in infarcted myocardium as well as its plasma course, in relation to those of CRP, are in line with a supposed pro-inflammatory role during AMI for sPLA(2) as a generator of lysophospholipids serving as ligands for CRP.

N(omega)-(carboxymethyl)lysine depositions in human aortic heart valves: similarities with atherosclerotic blood vessels.

Recent studies indicate a role of atherosclerosis-like changes involved in the pathogenesis of aortic valve stenosis. Interestingly, one of the major advanced glycation end products (AGEs), N(omega)-(carboxymethyl)lysine (CML) has been related to the process of atherosclerosis in blood vessels. In the present study, we have analyzed the presence of CML in degenerative altered aortic valves with atherosclerosis-like changes, and in degenerated mitral valves without atherosclerosis-like changes, derived from patients suffering from acute rheumatism during childhood. Degenerated and non-degenerated valves were derived from autopsy or obtained during cardiac surgery. The presence of CML was examined by immunohistochemistry. CML was found on the endothelium and fibroblasts in control aortic and mitral valves. Minor differences in CML staining were observed between control and degeneratively affected mitral valves. In contrast, in degenerated aortic valves, CML accumulation was found in macrophages and on calcification sites, comparable to that in atherosclerotic arteries, while the presence of CML staining on the endothelium and fibroblasts was significantly less as compared with control aortic valves. Our data support the hypothesis that the process of degeneration of aortic valves resembles that of atherosclerosis in blood vessels. They suggest that CML also plays a role in the process of atherosclerosis in aortic valves.

Pressure-diameter relationship in the human greater saphenous vein.

BACKGROUND: Compliance of artificial and autologous vascular grafts is related to future patency. We investigated whether differences in compliance exist between saphenous vein grafts derived from the upper or lower leg, which might indicate upper or lower leg saphenous vein preference in coronary artery bypass surgery. Furthermore, the effect of perivenous application of fibrin glue on mechanical vein wall properties was studied to evaluate its possible use as perivenous graft support. METHODS: Vein segments (N = 10) from upper or lower leg saphenous vein grafts were collected for histopathologic examination and smooth muscle cell/extracellular matrix (SMC/ECM) ratio was calculated. This ratio is suggested to be related with vascular elastic compliance. In a second group vein graft segments (N = 6) from upper and lower leg were placed in an in vitro model generating stepwise increasing static pressure up to 150 cm H(2)O. Outer diameter was measured continuously with a video micrometer system. Distensibility was calculated from the pressure-diameter curves. A third group of vein graft segments (N = 7) was pressurized after fibrin glue application to prevent overdistension, and studied in the same setup. RESULTS: Vein segments from the lower leg demonstrated a consistent higher relative response compared with the upper leg saphenous vein graft (0.9176 +/- 0.03993 vs 0.5245 +/- 0.02512). Both reach a plateau in the high-pressure range (> 100 cm H(2)O). A significant difference in in vitro distensibility between upper and lower leg saphenous vein was only found at a pressure of 50 cm H(2)O (p < 0.05). With fibrin glue, support overdistension is prevented as revealed by the maximum relative response between fibrin glue supported upper and lower leg saphenous vein segments (0.4080 +/- 0.02464 vs 0.582 +/- 0.051), and no plateau is reached in the pressure range up to 150 cm H(2)O. CONCLUSIONS: No upper or lower leg saphenous vein preference could be deduced from the differences in pressure-diameter response due to loss of distensibility (and thus of compliance) in the high-pressure range. Fibrin glue effectively prevents overdistension and preserves some distensibility in the high-pressure range in both the upper and lower leg saphenous vein. This might provide a basis for clinical application of perivenous support.

Human papillomavirus infection in women with and without cervical cancer in Tbilisi, Georgia.

BACKGROUND: No accurate estimates of cervical cancer incidence or mortality currently exist in Georgia. Nor are there any data on the population-based prevalence of high-risk (HR) human papillomavirus (HPV) infection, which, in the absence of good-quality screening, is known to correlate with cervical cancer incidence. METHODS: We obtained cervical cell specimens from 1309 women aged 18-59 years from the general population of Tbilisi, and also from 91 locally diagnosed invasive cervical cancers (ICC). DNA of 44 HPV types was tested for using a GP5+/6+-based PCR assay. RESULTS: In the general population (of whom 2% reported a previous Pap smear) HPV prevalence was 13.5% (95% CI: 11.6-15.9), being highest in women aged 25-34 years (18.7%) and falling to between 8.6% and 9.5% for all age groups above 34 years. HR HPV prevalence was 8.6% overall, being 6.8% and 38.9% among women with normal and abnormal cytology, respectively. HPV45 (1.6%) was the most common type in women with normal cytology, whereas HPV16 predominated among women with cervical abnormalities (including 7 of 10 histologically confirmed cervical intraepithelial neoplasia 2/3) and among ICC (57.6%). The next most common types in ICC in Georgia were HPV45 and 18 (13.2 and 11.0%, respectively). CONCLUSIONS: We report a relatively high burden of HPV infection in Tbilisi, Georgia. Improving cervical cancer prevention, through screening and/or HPV vaccination, is an important public health issue in Georgia, where 70% of ICC are theoretically preventable by HPV16/18 vaccines.