Quantifying intraepithelial lymphocytes and subepithelial collagen band in microscopic colitis, extracting insights into the interrelationship of lymphocytic and collagenous colitis.

Microscopic colitis (MC) is the umbrella term for the conditions termed lymphocytic colitis (LC) and collagenous colitis (CC). LC with thickening of the subepithelial collagen band or CC with increased number of intraepithelial T- lymphocytes (IELs) is often seen in MC and may lead to difficulties in correct histological classification. We investigated the extent of overlapping features of CC and LC in 60 cases of MC by measuring the exact thickness of the subepithelial collagen band in Van Gieson stained slides and quantifying number of IELs in CD3 stained slides by digital image analysis. A thickened collagen band was observed in nine out of 29 cases with LC (31%) and an increased number of IELs in all 23 cases of CC (100%). There was no correlation between the thickness of the collagen band and number of IELs. Due to the increased number of IELs in all cases of CC we consider the lymphocytic inflammatory infiltration of the mucosa to be the essential histopathological feature of MC. However, although LC and CC are related due to the lymphocytic inflammation, the non-linear correlation of number of IELs and thickness of the collagenous band indicate differences in their pathogenesis.

Application of automated image analysis reduces the workload of manual screening of sentinel lymph node biopsies in breast cancer.

AIMS: Breast cancer is one of the most common cancer diseases in women, with >1.67 million cases being diagnosed worldwide each year. In breast cancer, the sentinel lymph node (SLN) pinpoints the first lymph node(s) into which the tumour spreads, and it is usually located in the ipsilateral axilla. In patients with no clinical signs of metastatic disease in the axilla, an SLN biopsy (SLNB) is performed. Assessment of metastases in the SLNB, when using a conventional microscope, is performed by manually observing a metastasis and measuring its size and/or counting the number of tumour cells. This is done essentially to categorize the type of metastasis as macrometastasis, micrometastasis, or isolated tumour cells, which is used to determine which treatment the breast cancer patient will benefit most from. The aim of this study was to evaluate whether digital image analysis can be applied as a screening tool for SNLB assessment without compromising the diagnostic accuracy. MATERIALS AND RESULTS: Consecutive SLNBs from 135 patients with localized breast cancer receiving surgery in the period February to August 2015 were collected and included in this study. Of the 135 patients, 35 were received at the Department of Pathology, Rigshospitalet, Copenhagen University Hospital, 50 at the Department of Pathology, Zealand University Hospital, and 50 at the Department of Pathology, Odense University Hospital. Formalin-fixed paraffin-embedded tissue sections were analysed by immunohistochemistry with the BenchMark ULTRA Ventana platform. Rigshospitalet used a mixture of cytokeratin (CK) 7 and CK19, Zealand University Hospital used pancytokeratin AE1/AE3 and Odense used pancytokeratin CAM5.2 for detection of epithelial tumour cells. Slides were stained locally. SLNB sections were assessed in a conventional microscope according to national guidelines for SLNBs in breast cancer patients. The immunohistochemically stained sections were scanned with a Hamamatsu NanoZoomer-XR digital whole slide scanner, and the images were analysed with Visiopharm's software by use of a custom-made algorithm for SLNBs in breast cancer. The algorithm was optimized to the CK antibodies and the local laboratory conditions, on the basis of staining intensity and background staining. Conventional microscopy was used as the gold standard for assessment of positive tumour cells, and the results were compared with those from digital image analysis. The algorithm showed a sensitivity of 100% (that is, no false-negative slides were observed), including 67.2%, 19.2% and 56.1% of the slides from the three pathology departments being negative, respectively. This means that, on average, the workload could have been decreased by 58.2% by use of the digital SLNB algorithm as a screening tool. CONCLUSIONS: The SLNB algorithm showed a sensitivity of 100% regardless of the antibody used for immunohistochemistry and the staining protocol. No false-negative slides were observed, which proves that the SLNB algorithm is an ideal screening tool for selecting those slides that a pathologist does not need to see. The implementation of automated digital image analysis of SLNBs in breast cancer would decrease the workload in this context for examining pathologists by almost 60%.

Optimizing HER2 assessment in breast cancer: application of automated image analysis.

In breast cancer, analysis of HER2 expression is pivotal for treatment decision. This study aimed at comparing digital, automated image analysis with manual reading using the HER2-CONNECT algorithm (Visiopharm) in order to minimize the number of equivocal 2+ scores and the need for reflex fluorescence in situ hybridization (FISH) analysis. Consecutive samples from 462 patients were included. Tissue micro arrays (TMAs) were routinely manufactured including two 2 mm cores from each patient, and each core was assessed in order to ensure the presence of invasive carcinoma. Immunohistochemical staining (IHC) was performed with Roche/Ventana's HER2 ready-to-use kit. TMAs were scanned in a Zeiss Axio Z1 scanner, and one batch analysis of the HER2-CONNECT algorithm including all core samples was run using Visiopharm's cloud-based software. The automated reading was compared to conventional manual assessment of HER2 protein expression, together with FISH analysis of HER2 gene amplification for borderline (2+) protein expression samples. Compared to FISH analysis, manual assessment of the HER2 protein expression demonstrated a sensitivity of 85.8% and a specificity of 86.0% with 14.0% equivocal samples. With HER2-CONNECT, sensitivity increased to 100 % and specificity to 95.5% with less than 4.5% equivocal. Total agreement when comparing HER2-CONNECT with manual IHC assessment supplemented by FISH for borderline (2+) cases was 93.6%. Application of automated image analysis for HER2 protein expression instead of manual assessment decreases the need for supplementary FISH testing by 68%. In the routine diagnostic setting, this would have significant impact on cost reduction and turn-around time.

Technical Note: Measuring the thickness of histological sections by detecting fluorescence intensity of embedding foam.

Fluorescence intensity of embedding foam in paraffin blocks can be used to measure the thickness of histological microsections. We embedded samples of embedding foam and produced several microsections of varying thicknesses using routine processing and staining. Fluorescence intensity in the blue area of the embedding foam detected with a slide scanner was compared to absolute thickness as measured using confocal microscopy. Correlation analysis displayed a clear linear correlation with convincingly low prediction interval. The concept of measuring thickness of histological microsections by detecting fluorescence intensity of embedding foam is suggested as an approach to high-throughput measuring of histological sections applicable for a fully digitized pathology department. No acquisition of dedicated equipment is required and the method can be applied as a fully automated technique requiring no time consumption.

Consultation on urological specimens from referred cancer patients using real-time digital microscopy: Optimizing the workflow.

INTRODUCTION: Centralization of cancer treatment entails a reassessment of the diagnostic tissue specimens. Packaging and shipment of glass slides from the local to the central pathology unit means that the standard procedure is time-consuming and that it is difficult to comply with governmental requirements. The aim was to evaluate whether real-time digital microscopy for urological cancer specimens during the primary diagnostic process can replace subsequent physical slide referral and reassessment without compromising diagnostic safety. METHODS: From May to October 2014, tissue specimens from 130 patients with urological cancer received at Næstved Hospital's Pathology Department, and expected to be referred for further treatment at cancer unit of a university hospital, were diagnosed using standard light microscopy. In the event of diagnostic uncertainty, the VisionTek digital microscope (Sakura Finetek) was employed. The Pathology Department at Næstved Hospital was equipped with a digital microscope and three consultant pathologists were stationed at Rigshospitalet with workstations optimized for digital microscopy. Representative slides for each case were selected for consultation and live digital consultation took place over the telephone using remote access software. Time of start and finish for each case was logged. For the physically referred cases, time from arrival to sign-out was logged in the national pathology information system, and time spent on microscopy and reporting was noted manually. Diagnosis, number of involved biopsies, grade, and stage were compared between digital microscopy and conventional microscopy. RESULTS: Complete data were available for all 130 cases. Standard procedure with referral of urological cancer specimens took a mean of 8 min 56 s for microscopy, reporting and sign-out per case. For live digital consultations, a mean of 18 min 37 s was spent on each consultation with 4 min 43 s for each case, depending on the number of digital slides included. Only in two cases could a consensus regarding the diagnosis not be reached during live consultation; this did not, it should be noted, affect patient treatment. Complete agreement between conventional and digital histopathology diagnosis was reached in all the 53 patients referred to central pathology units. The participating pathologists were in general comfortable using live digital microscopy, but they emphasized that a fast internet connection was essential for a smooth consultation. DISCUSSION AND CONCLUSION: An almost perfect agreement between live digital and conventional microscopy was observed in this study. Live digital consultation allowed cases to be referred from local hospitals to central cancer units without the standard delay caused by shipment. Only a few preselected specimen slides for each patient were presented in live consultation, which reduced the time spent on diagnosis compared to using the conventional method. Implementation of real-time digital microscopy would result in quicker turnaround and patient referral time, and with careful selection of relevant specimen slides for consultation, diagnostic safety would not be compromised.

Quantitative analysis of myocardial tissue with digital autofluorescence microscopy.

BACKGROUND: The opportunity offered by whole slide scanners of automated histological analysis implies an ever increasing importance of digital pathology. To go beyond the importance of conventional pathology, however, digital pathology may need a basic histological starting point similar to that of hematoxylin and eosin staining in conventional pathology. This study presents an automated fluorescence-based microscopy approach providing highly detailed morphological data from unstained microsections. This data may provide a basic histological starting point from which further digital analysis including staining may benefit. METHODS: This study explores the inherent tissue fluorescence, also known as autofluorescence, as a mean to quantitate cardiac tissue components in histological microsections. Data acquisition using a commercially available whole slide scanner and an image-based quantitation algorithm are presented. RESULTS: It is shown that the autofluorescence intensity of unstained microsections at two different wavelengths is a suitable starting point for automated digital analysis of myocytes, fibrous tissue, lipofuscin, and the extracellular compartment. The output of the method is absolute quantitation along with accurate outlines of above-mentioned components. The digital quantitations are verified by comparison to point grid quantitations performed on the microsections after Van Gieson staining. CONCLUSION: The presented method is amply described as a prestain multicomponent quantitation and outlining tool for histological sections of cardiac tissue. The main perspective is the opportunity for combination with digital analysis of stained microsections, for which the method may provide an accurate digital framework.

ERG protein expression over time: from diagnostic biopsies to radical prostatectomy specimens in clinically localised prostate cancer.

AIMS: We evaluated the consistency in ERG protein expression from diagnostic specimens through rebiopsies to radical prostatectomies in patients with clinically localised prostate cancer to investigate the validity of ERG status in biopsies. METHODS: ERG expression was assessed by immunohistochemistry (IHC) in 625 biopsy sets and 86 radical prostatectomy specimens from 265 patients with prostate cancer managed on active surveillance. For IHC, a rabbit monoclonal primary antibody was used (clone: EPR3864). TMPRSS2-ERG fluorescence in situ hybridisation (FISH) analyses were performed in 74 biopsies using the FISH ZytoLight TriCheck Probe (SPEC ERG/TMPRSS2). FISH results were correlated with IHC findings. RESULTS: The concordance between FISH and IHC was 97.3% and IHC demonstrated a sensitivity and specificity for ERG rearrangement of 100% and 95.5%, respectively. Applying IHC, 38.1% of patients were ERG-positive, 53.6% were ERG-negative and 8.3% showed both ERG-positive and negative tumour foci (ERG heterogeneous) at diagnosis. When ERG status was dichotomised (ERG-positive or heterogeneous vs ERG-negative), 95.6%-97.1% of patients did not experience ERG reclassification during the first two rounds of rebiopsies. The concordance in ERG status between biopsies and surgical specimen was 89.5%-94.2% depending on the number of rebiopsies included. Sampling bias was assumed to explain most (81.3%) of the mismatches in ERG status. CONCLUSIONS: Consistency in ERG status ranged from 90% to 95% for patients undergoing serial biopsies and radical prostatectomy. This indicates that biopsies can be used reliably to investigate ERG's prognostic and predictive value.