Nuclear size measurement for distinguishing urothelial carcinomas from reactive urothelium on tissue sections

Nuclear long diameter as a new criterion to distinguish high-grade urothelial carcinoma cells from benign reactive cells

OBJECTIVE

Recently, the nuclear area has attracted attention as a morphological parameter to differentiate high-grade urothelial carcinoma (HGUC) cells from benign reactive cells. The nuclear long diameter (NLD) strongly correlates with the nuclear area and is easy to subjectively estimate. Therefore, this study examined the usefulness of the NLD-to-neutrophil diameter ratio for detecting HGUC cells in urine cytology.

METHODS

This study included 29, 26 and 18 patients with HGUC, glomerular disease and urolithiasis respectively. An image analysis system was used to measure the NLD of HGUC and benign reactive cells (reactive renal tubular cells and reactive urothelial cells) and the neutrophil diameter that appeared in the voided urine in these cases. The NLD index was calculated using the NLD-to-neutrophil diameter ratio. We subsequently compared HGUC and benign reactive cells with respect to NLD and NLD indices. In addition, the HGUC cell group and benign reactive cell group were compared by selecting the five cells with the largest NLD and NLD index on each slide.

RESULTS

The NLD and NLD indices of HGUC cells were significantly higher than those of benign reactive cells in all cells and in the five cells with the largest NLD and NLD indices. The cut-off value of the NLD index for detecting HGUC cells was 1.25 in all cells and 1.80 in the five cells with the largest NLD index.

CONCLUSIONS

The NLD index is a useful parameter that can be introduced into routine microscopic examinations to differentiate HGUC cells from benign reactive cells.

Morphometric analysis of nuclear shape irregularity as a novel predictor of programmed death-ligand 1 expression in lung squamous cell carcinoma

Immune checkpoint inhibitor (ICI) therapy has been established as one of the key treatment strategies for lung squamous cell carcinoma (LUSQ). The status of programmed death-ligand 1 (PD-L1) in tumor cells and/or immune cells using immunohistochemistry has been primarily used as a surrogate marker for determining ICI treatment; however, when the tissues to be examined are small, false-negative results could be unavoidable due to the heterogeneity of PD-L1 immunoreactivity. To overcome this practical limitation, we attempted to explore the status of nuclear atypia evaluated using morphometry as a potential predictor of PD-L1 status in LUSQ. We correlated the parameters related to nuclear atypia with PD-L1 status using two different cohorts of LUSQ patients (95 cases from The Cancer Genome Atlas database and 30 cases from the Miyagi Cancer Center). Furthermore, we studied the gene mutation status to elucidate the genetic profile of PD-L1 predictable cases. The results revealed that nuclear atypia, especially morphometric parameters related to nuclear shape irregularity, including aspect ratio, circularity, roundness, and solidity, were all significantly associated with PD-L1 status. Additionally, LUSQ cases with high PD-L1 expression and pronounced nuclear atypia were significantly associated with C10orf71 and COL14A1 mutations compared with those with low PD-L1 expression and mild nuclear atypia. We demonstrated for the first time that nuclear shape irregularity could represent a novel predictor of PD-L1 expression in LUSQ. Including the morphometric parameters related to nuclear atypia in conjunction with PD-L1 status could help determine an effective ICI therapeutic strategy; however, further investigation is required.

The usefulness of nuclear area in the diagnosis of high-grade urothelial carcinoma cells in voided urine cytology

OBJECTIVE

The Paris System for Reporting Urinary Cytology considered the nuclear-to-cytoplasmic (N:C) ratio as the most important cytomorphological feature for detecting high-grade urothelial carcinoma (HGUC) cells. Few quantitative studies have been conducted on other features although quantitative studies on the N:C ratio have been reported. Therefore, this study quantitatively analysed important cytomorphological features in distinguishing benign reactive cells from HGUC cells.

METHODS

We analysed 2866 cells from the urine of 52 patients. A digital image analyser was used to quantitatively measure the nuclear area, cell area, N:C ratio, and nuclear roundness for HGUC cells and benign reactive cells. Additionally, the diagnostic value of quantitative cytomorphological criteria in HGUC cells was evaluated by the receiver operating characteristic curve.

RESULTS

The area under the curve for the prediction of HGUC cells for all cells and the top five cells was in the following order: nuclear area (0.920 and 0.992, respectively), N:C ratio (0.849 and 0.977), cell area (0.781 and 0.920), and nuclear roundness (0.624 and 0.605). The best cutoff value of the N:C ratio to differentiate HGUC cells from benign reactive cells was 0.438, and using the N:C ratio of 0.702, the positive predictive value obtained was 100%.

CONCLUSIONS

Our study indicated that nuclear area is a more important cytomorphological criterion than the N:C ratio for HGUC cell detection. Moreover, extracted data of the top five cells were more valuable than the data of all cells, which can be helpful in the routine practice and future criteria definition in urine cytology.

Quantitative nuclear grading: an objective, artificial intelligence-facilitated foundation for grading noninvasive papillary urothelial carcinoma

In non-muscle invasive bladder cancer, grade drives important treatment and management decisions. However, grading is complex, qualitative, and has considerable inter-and intra-observer variability. Previous literature showed that nuclear features quantitatively differ between bladder cancer grades, but these studies were limited in size and scope. Here, we measure morphometric features relevant to grading criteria and build simplified classification models that objectively distinguish between grades of non-invasive papillary urothelial carcinoma (NPUC). We analyzed 516 low-grade and 125 high-grade 1.0 mm diameter image samples from a cohort of 371 NPUC cases. All images underwent WHO/ISUP 2004 consensus pathologist grading at our institution that was subsequently validated by expert genitourinary pathologists from two additional institutions. Automated software segmented tissue regions and measured nuclear features of size, shape, and mitotic rate for millions of nuclei. We then analyzed differences between grades and constructed classification models which had accuracies up to 88% and areas under the curve as high as 0.94. Variation in the nuclear area was the best univariate discriminator and was prioritized, along with the mitotic index, in the top-performing classifiers. Adding shape-related variables improved accuracy further. These findings indicate that nuclear morphometry and automated mitotic figure counts can be used to objectively differentiate between grades of NPUC. Future efforts will adapt the workflow to whole slides and tune grading thresholds to best reflect time to recurrence and progression. Defining these essential quantitative elements of grading has the potential to revolutionize pathologic assessment and provide a starting point from which to improve the prognostic utility of grade.

Characterization of the Peri-Membrane Fluorescence Phenomenon Allowing the Detection of Urothelial Tumor Cells in Urine

Simple Summary

To detect bladder cancer (BC), urinary cytology and cystoscopy are the primary diagnostic tests used. Urine cytology is non-invasive, easy to collect, with medium sensitivity and high specificity. It is an effective way to detect high-grade BC, but it is less effective on low-grade BC because the rate of equivocal results is much higher, making them difficult to detect. Despite the implementation of new diagnostics, urinary cytology and cystoscopy remain the gold standard. Instead of looking for new diagnostics, one of the new research areas is the improvement of urinary cytology. Recently, the fluorescent properties of plasma membranes of urothelial tumor cells, called peri-membrane fluorescence, found in urinary cytology have been shown to be useful in improving the early detection of BC. The main objective of this study was to characterize the peri-membrane fluorescence allowing the detection of urothelial tumor cells in urine.

Abstract

Urine cytology is non-invasive, easy to collect, with medium sensitivity and a high specificity. It is an effective way to detect high-grade bladder cancer (BC), but it is less effective on low-grade BC because the rate of equivocal results is much higher. Recently, the fluorescent properties of plasma membranes of urothelial tumor cells (UTC) found in urine cytology have been shown to be useful in improving the early detection of BC. This phenomenon is called peri-membrane fluorescence (PMF). Based on previous studies that have identified the PMF on UTCs, the main objective was to characterize this phenomenon. For this study, a software was specially created to quantify the PMF of all tested cells and different treatments performed. PMF was not found to be a morphological and discriminating feature of UTCs, all cells in shape and not from urine show PMF. We were able to highlight the crucial role of plasma membrane integrity in the maintenance of PMF. Finally, it was found that the induction of a strong cellular stress induced a decrease in PMF, mimicking what was observed in non-tumor cells collected from urine. These results suggest that PMF is found in cells able to resist this stress, such as tumor cells.

Pathomics in urology

PURPOSE OF REVIEW

Pathomics, the fusion of digitalized pathology and artificial intelligence, is currently changing the landscape of medical pathology and biologic disease classification. In this review, we give an overview of Pathomics and summarize its most relevant applications in urology.

RECENT FINDINGS

There is a steady rise in the number of studies employing Pathomics, and especially deep learning, in urology. In prostate cancer, several algorithms have been developed for the automatic differentiation between benign and malignant lesions and to differentiate Gleason scores. Furthermore, several applications have been developed for the automatic cancer cell detection in urine and for tumor assessment in renal cancer. Despite the explosion in research, Pathomics is not fully ready yet for widespread clinical application.

SUMMARY

In prostate cancer and other urologic pathologies, Pathomics is avidly being researched with commercial applications on the close horizon. Pathomics is set to improve the accuracy, speed, reliability, cost-effectiveness and generalizability of pathology, especially in uro-oncology.

A biomimetic model of 3D fluid extracellular macromolecular crowding microenvironment fine-tunes ovarian cancer cells dissemination phenotype

An early fundamental step in ovarian cancer progression is the dissemination of cancer cells through liquid environments, one of them being cancer ascites accumulated in the peritoneal cavity. These biological fluids are highly crowded with a high total macromolecule concentration. This biophysical property of fluids is widely used in tissue engineering for a few decades now, yet is largely underrated in cancer biomimetic models. To unravel the role of fluids extracellular macromolecular crowding (MMC), we exposed ovarian cancer cells (OCC) to high molecular weight inert polymer solutions. High macromolecular composition of extracellular liquid presented a differential effect: i) it impeded non-adherent OCC aggregation in suspension and, decreased their adhesion; ii) it promoted adherent OCC migration by decreasing extracellular matrix deposition. Besides, there seemed to be a direct link between the extracellular MMC and intracellular processes, especially the actin cytoskeleton organization and the nucleus morphology. In conclusion, extracellular fluid MMC orients OCC dissemination phenotype. Integrating MMC seems crucial to produce more relevant mimetic 3D in vitro fluid models to study ovarian dissemination but also to screen drugs.

Evolving concepts and use of immunohistochemical biomarkers in flat non-neoplastic urothelial lesions: WHO 2016 classification update with diagnostic algorithm

CONTEXT

The classification of flat non-neoplastic urothelial lesions has been evolved through the years in the attempt to better define a spectrum of morphologic entities with somewhat overlapping features. Differentiating these lesions is important because of differences in patient management and clinical outcome. Materials and methods and objective: A systematic review of the literature has been carried out in order to (1) assess the most striking clinical features of each lesion and (2) identify those morphological traits and immunophenotypical markers which may aid in the differential diagnosis.

RESULTS AND CONCLUSION

Our results point out the importance of a proper definition of flat non-neoplastic urothelial lesions in order to predict clinical behaviour and allow tailored patient management; therefore, we attempted to construct a novel and "easy to use" algorithm for a clear, standardized and evidence-based pathological diagnosis.

Nuclear morphologies: their diversity and functional relevance

Studies of chromosome and genome biology often focus on condensed chromatin in the form of chromosomes and neglect the non-dividing cells. Even when interphase nuclei are considered, they are often then treated as interchangeable round objects. However, different cell types can have very different nuclear shapes, and these shapes have impacts on cellular function; indeed, many pathologies are linked with alterations to nuclear shape. In this review, we describe some of the nuclear morphologies beyond the spherical and ovoid. Many of the leukocytes of the immune system have lobed nuclei, which aid their flexibility and migration; smooth muscle cells have a spindle shaped nucleus, which must deform during muscle contractions; spermatozoa have highly condensed nuclei which adopt varied shapes, potentially associated with swimming efficiency. Nuclei are not passive passengers within the cell. There are clear effects of nuclear shape on the transcriptional activity of the cell. Recent work has shown that regulation of gene expression can be influenced by nuclear morphology, and that cells can drastically remodel their chromatin during differentiation. The link between the nucleoskeleton and the cytoskeleton at the nuclear envelope provides a mechanism for transmission of mechanical forces into the nucleus, directly affecting chromatin compaction and organisation.