Defining the area of mitoses counting in invasive breast cancer using whole slide image

Although counting mitoses is part of breast cancer grading, concordance studies showed low agreement. Refining the criteria for mitotic counting can improve concordance, particularly when using whole slide images (WSIs). This study aims to refine the methodology for optimal mitoses counting on WSI. Digital images of 595 hematoxylin and eosin stained sections were evaluated. Several morphological criteria were investigated and applied to define mitotic hotspots. Reproducibility, representativeness, time, and association with outcome were the criteria used to evaluate the best area size for mitoses counting. Three approaches for scoring mitoses on WSIs (single and multiple annotated rectangles and multiple digital high-power (×40) screen fields (HPSFs)) were evaluated. The relative increase in tumor cell density was the most significant and easiest parameter for identifying hotspots. Counting mitoses in 3 mm2 area was the most representative regarding saturation and concordance levels. Counting in area <2 mm2 resulted in a significant reduction in mitotic count (P = 0.02), whereas counting in area ≥4 mm2 was time-consuming and did not add a significant rise in overall mitotic count (P = 0.08). Using multiple HPSF, following calibration, provided the most reliable, timesaving, and practical method for mitoses counting on WSI. This study provides evidence-based methodology for defining the area and methodology of visual mitoses counting using WSI. Visual mitoses scoring on WSI can be performed reliably by adjusting the number of monitor screens.

Counting Mitoses With Digital Pathology in Breast Phyllodes Tumors

Context.— Mitotic count is an important histologic criterion for grading and prognostication in phyllodes tumors (PTs). Counting mitoses is a routine practice for pathologists evaluating neoplasms, but different microscopes, variable field selection, and areas have led to possible misclassification. Objective.— To determine whether 10 high-power fields (HPFs) or whole slide mitotic counts correlated better with PT clinicopathologic parameters using digital pathology (DP). We also aimed to find out whether this study might serve as a basis for an artificial intelligence (AI) protocol to count mitosis. Design.— Representative slides were chosen from 93 cases of PTs diagnosed between 2014 and 2015. The slides were scanned and viewed with DP. Mitotic counting was conducted on the whole slide image, before choosing 10 HPFs and demarcating the tumor area in DP. Values of mitoses per millimeter squared were used to compare results between 10 HPFs and the whole slide. Correlations with clinicopathologic parameters were conducted. Results.— Both whole slide counting of mitoses and 10 HPFs had similar statistically significant correlation coefficients with grade, stromal atypia, and stromal hypercellularity. Neither whole slide mitotic counts nor mitoses per 10 HPFs showed statistically significant correlations with patient age and tumor size. Conclusions.— Accurate mitosis counting in breast PTs is important for grading. Exploring machine learning on digital whole slides may influence approaches to training, testing, and validation of a future AI algorithm.

Assessment of Interobserver Variability in Mitotic Figure Counting in Different Histological Grades of Oral Squamous Cell Carcinoma

ABSTRACT Mitotic counting is often used for classification, grading and prognosis of tumors. The count usually stands as a decision point for treatment as well. The easiest way of counting the number of mitoses is done by screening routine H&E stained slides. However, for proper mitotic counting, certain strict protocols should be taken into consideration. This study on 30 cases of different grades of oral squamous cell carcinoma was undertaken to determine the interobserver variations in two different groups: Group1 (A1, A2), who were given certain criteria to be followed during the counting of the mitotic figures and group 2 investigators (B1, B2) who were unaware of such criteria. The paired t-test gives a correlation of 0.988 and a significant difference of 0.000 between the two investigators in group 1. The correlation was 0.650 with a significant difference of 0.058 between two investigators in-group 2, indicating that group 1 observers exhibit good interobserver agreement. The results emphasize that following of strict protocols are of great help in determining the accuracy of mitotic counting. How to cite this article Yadav KS, Gonuguntla S, Ealla KKR, Velidandla SR, Reddy CRC, Prasanna MD, Bommu SR. Assessment of Interobserver Variability in Mitotic Figure Counting in Different Histological Grades of Oral Squamous Cell Carcinoma. J Contemp Dent Pract 2012;13(3):339-344.