Significance of Staining Intensity in Ki-67 Proliferation Index in Meningiomas, and a Critical Review of the Literature on Proliferation Index Assessment.

OBJECTIVE: Meningioma is the most common primary adult intracranial neoplasm, and proliferation indices (PI) rise with increasing grade from WHO CNS grade 1 to 3. Ki-67 immunohistochemistry (IHC) poses a variety of technical and interpretative challenges. Here, we specifically investigated the staining intensity and its effect on interpretation and final diagnosis. METHODS: 124 high and low-grade meningiomas of various grades were blindly evaluated using different counting strategies (CS) based on the staining intensity of the nuclei as darkest (CS1), darkest+intermediate (CS2), and any staining (CS3) in hot-spots (HS) and in the context of overall proliferative activity (OPA). RESULT: CSs in HS, OPA, and their average results were significantly different between low-grade and high-grade groups. PI obtained using CS3 yielded results that matched best with values expected for the corresponding WHO grade. CS had a profound impact on whether a LG meningioma would be diagnosed as one with a "high proliferation index." CONCLUSION: A large body of work exists on the counting methods, clinically significant cut-off values, and inter- and intra-observer variability for Ki-67 PI interpretation. We show that Ki-67 IHC staining intensity, which to our knowledge has not been previously systematically investigated, can have a significant effect on PI interpretation in settings that influence diagnostic and clinical management decisions.

Digital image analysis of Ki67 hotspot detection and index counting in gastroenteropancreatic neuroendocrine neoplasms.

The Ki-67 proliferative index plays a pivotal role in the subclassification of neuroendocrine neoplasm (NEN) according to the WHO Classification of Digestive System Tumors (5th edition), which designates neuroendocrine tumor (NET) grades 1, 2, and 3 for Ki-67 proliferative index of <3 %, 3-20 %, and >20 %, respectively. Proliferative index calculation must be performed in the hotspot, traditionally selected by visual scanning at low-power magnification. Recently, gradient map visualization has emerged as a tool for various purposes, including hotspot selection. This study includes 97 cases of gastrointestinal neuroendocrine neoplasms, with hotspots selected by bare eye and gradient map visualization (GM). Each hotspot was analyzed using three methods: eye estimation (EE), digital image analysis (DIA), and manual counting. Of the NENs studied, 91 % were NETs (26 % for G1, 55 % for G2, and 10 % for G3). Only 9 cases were neuroendocrine carcinoma (NEC). Between two hotspot selection methods, GM resulted in a higher grade in 14.77 % of cases, primarily upgrading from NET G1 to G2. Among the counting methods, DIA demonstrated substantial agreement with manual counting, both for pathologist and resident. Grading by other methods tended to result in a higher grade than MC (26.99 % with EE and 8.52 % with DIA). Given its clinical and statistical significance, this study advocates for the application of GM in hotspot selection to identify higher-grade tumors. Furthermore, DIA provides accurate grading, offering time efficiency over MC.

Enhancing mitosis quantification and detection in meningiomas with computational digital pathology.

Mitosis is a critical criterion for meningioma grading. However, pathologists' assessment of mitoses is subject to significant inter-observer variation due to challenges in locating mitosis hotspots and accurately detecting mitotic figures. To address this issue, we leverage digital pathology and propose a computational strategy to enhance pathologists' mitosis assessment. The strategy has two components: (1) A depth-first search algorithm that quantifies the mathematically maximum mitotic count in 10 consecutive high-power fields, which can enhance the preciseness, especially in cases with borderline mitotic count. (2) Implementing a collaborative sphere to group a set of pathologists to detect mitoses under each high-power field, which can mitigate subjective random errors in mitosis detection originating from individual detection errors. By depth-first search algorithm (1) , we analyzed 19 meningioma slides and discovered that the proposed algorithm upgraded two borderline cases verified at consensus conferences. This improvement is attributed to the algorithm's ability to quantify the mitotic count more comprehensively compared to other conventional methods of counting mitoses. In implementing a collaborative sphere (2) , we evaluated the correctness of mitosis detection from grouped pathologists and/or pathology residents, where each member of the group annotated a set of 48 high-power field images for mitotic figures independently. We report that groups with sizes of three can achieve an average precision of 0.897 and sensitivity of 0.699 in mitosis detection, which is higher than an average pathologist in this study (precision: 0.750, sensitivity: 0.667). The proposed computational strategy can be integrated with artificial intelligence workflow, which envisions the future of achieving a rapid and robust mitosis assessment by interactive assisting algorithms that can ultimately benefit patient management.

Prognostic importance of mitosis quantification and PHH3 expression in oral epithelial dysplasia.

Oral epithelial dysplasia (OED) is diagnosed and graded using a range of histological features, making grading subjective and challenging. Mitotic counting and phosphohistone-H3 (PHH3) staining have been used for the prognostication of various malignancies; however, their importance in OED remains unexplored. This study conducts a quantitative analysis of mitotic activity in OED using both haematoxylin and eosin (H&E)-stained slides and immunohistochemical (IHC) staining for PHH3. Specifically, the diagnostic and prognostic importance of mitotic number, mitotic type and intra-epithelial location is evaluated. Whole slide images (WSI) of OED (n = 60) and non-dysplastic tissue (n = 8) were prepared for analysis. Five-year follow-up data was collected. The total number of mitosis (TNOM), mitosis type and intra-epithelial location was manually evaluated on H&E images and a digital mitotic count performed on PHH3-stained WSI. Statistical associations between these features and OED grade, malignant transformation and OED recurrence were determined. Mitosis count increased with grade severity (H&E: p < 0.005; IHC: p < 0.05), and grade-based differences were seen for mitosis type and location (p < 0.05). The ratio of normal-to-abnormal mitoses was higher in OED (1.61) than control (1.25) and reduced with grade severity. TNOM, type and location were better predictors when combined with histological grading, with the most prognostic models demonstrating an AUROC of 0.81 for transformation and 0.78 for recurrence, exceeding conventional grading. Mitosis quantification and PHH3 staining can be an adjunct to conventional H&E assessment and grading for the prediction of OED prognosis. Validation on larger multicentre cohorts is needed to establish these findings.

Improving mitotic cell counting accuracy and efficiency using phosphohistone-H3 (PHH3) antibody counterstained with haematoxylin and eosin as part of breast cancer grading.

BACKGROUND: Mitotic count in breast cancer is an important prognostic marker. Unfortunately, substantial inter- and intraobserver variation exists when pathologists manually count mitotic figures. To alleviate this problem, we developed a new technique incorporating both haematoxylin and eosin (H&E) and phosphorylated histone H3 (PHH3), a marker highly specific to mitotic figures, and compared it to visual scoring of mitotic figures using H&E only. METHODS: Two full-face sections from 97 cases were cut, one stained with H&E only, and the other was stained with PHH3 and counterstained with H&E (PHH3-H&E). Counting mitoses using PHH3-H&E was compared to traditional mitoses scoring using H&E in terms of reproducibility, scoring time, and the ability to detect mitosis hotspots. We assessed the agreement between manual and image analysis-assisted scoring of mitotic figures using H&E and PHH3-H&E-stained cells. The diagnostic performance of PHH3 in detecting mitotic figures in terms of sensitivity and specificity was measured. Finally, PHH3 replaced the mitosis score in a multivariate analysis to assess its significance. RESULTS: Pathologists detected significantly higher mitotic figures using the PHH3-H&E (median ± SD, 20 ± 33) compared with H&E alone (median ± SD, 16 ± 25), P < 0.001. The concordance between pathologists in identifying mitotic figures was highest when using the dual PHH3-H&E technique; in addition, it highlighted mitotic figures at low power, allowing better agreement on choosing the hotspot area (k = 0.842) in comparison with standard H&E (k = 0.625). A better agreement between image analysis-assisted software and the human eye was observed for PHH3-stained mitotic figures. When the mitosis score was replaced with PHH3 in a Cox regression model with other grade components, PHH3 was an independent predictor of survival (hazard ratio [HR] 5.66, 95% confidence interval [CI] 1.92-16.69; P = 0.002), and even showed a more significant association with breast cancer-specific survival (BCSS) than mitosis (HR 3.63, 95% CI 1.49-8.86; P = 0.005) and Ki67 (P = 0.27). CONCLUSION: Using PHH3-H&E-stained slides can reliably be used in routine scoring of mitotic figures and integrating both techniques will compensate for each other's limitations and improve diagnostic accuracy, quality, and precision.

Mitotic Index Determination on Live Cells From Label-Free Acquired Quantitative Phase Images Using a Supervised Autoencoder.

This interdisciplinary work focuses on the interest of a new auto-encoder for supervised classification of live cell populations growing in a thermostated imaging station and acquired by a Quantitative Phase Imaging (QPI) camera. This type of camera produces interferograms that have to be processed to extract features derived from quantitative linear retardance and birefringence measurements. QPI is performed on living populations without any manipulation or treatment of the cells. We use the efficient new autoencoder classification method instead of the classical Douglas-Rachford method. Using this new supervised autoencoder, we show that the accuracy of the classification of the cells present in the mitotic phase of the cell cycle is very high using QPI features. This is a very important finding since we demonstrate that it is now possible to very precisely follow cell growth in a non-invasive manner, without any bias. No dye or any kind of markers are necessary for this live monitoring. Any studies requiring analysis of cell growth or cellular response to any treatment could benefit from this new approach by simply monitoring the proportion of cells entering mitosis in the studied cell population.

Biomarkers of geno- and cytotoxicity in the native broad-snouted caiman (Caiman latirostris): Chromosomal aberrations and mitotic index.

We evaluated the sensitivity of the chromosomal aberration (CA) and mitotic index (MI) assays on peripheral blood lymphocytes (PBLs) of Caiman latirostris, following ex vivo exposure to the alkylating agent, MMS. Two concentrations of MMS were tested in cultured peripheral blood. Relative to controls, MMS exposure reduced the number of metaphases observed, but both the numbers of cells with MN and the percentages of aberrant metaphases increased. The types of CA identified were chromosome and chromatid breaks, chromosomal rearrangements, monosomies, and nullisomies, with significantly higher values in the MMS-exposed groups. The incorporation of the MI and CA tests in C. latirostris can provide information on damage caused by xenobiotic exposures.

Counting mitoses: SI(ze) matters!

Mitoses are often assessed by pathologists to assist the diagnosis of cancer, and to grade malignancy, informing prognosis. Historically, this has been done by expressing the number of mitoses per n high power fields (HPFs), ignoring the fact that microscope fields may differ substantially, even at the same high power (×400) magnification. Despite a requirement to define HPF size in scientific papers, many authors fail to address this issue adequately. The problem is compounded by the switch to digital pathology systems, where ×400 equivalent fields are rectangular and also vary in the area displayed. The potential for error is considerable, and at times this may affect patient care. This is easily solved by the use of standardized international (SI) units. We, therefore, recommend that features such as mitoses are always counted per mm2, with an indication of the area to be counted and the method used (usually "hotspot" or "average") to obtain the results.

Mitotic count: A need for standardization / Recuento mitótico: una necesidad de estandarización

PURPOSE: The mitotic count (MC), number of mitosis per unit area, is a very important parameter frequently used for classification and grading of some tumors. Traditionally, the MC has been expressed in terms of number of mitoses per high power field. The size of the field of view can vary greatly among different microscopes. In order to avoid under or overestimation of mitotic count, a conversion needs to be made. METHODS: A simple formula based on a simple rule of three has been devised to standardize the mitotic count to the reference area by multiplying the number of mitotic figures by a correction factor which has been calculated for the most frequently used microscopes and various common tumors. RESULTS AND CONCLUSIONS: We propose this simple method, which involves only a single multiplication, to standardize the mitotic count to the reference area

OBJETIVO: El recuento mitótico o número de mitosis por unidad de área, es un parámetro muy importante utilizado frecuentemente para clasificar y estadificar ciertos tumores. Tradicionalmente se ha expresado el recuento mitótico en términos de número de mitosis por campos de alta frecuencia. El tamaño del campo de visión puede variar ampliamente entre los diferentes microscopios. A fin de evitar la infraestimación o sobreestimación del recuento mitótico, debe realizarse una conversión. MÉTODOS: Por medio de una simple regla de tres, se ha obtenido una fórmula simple para estandarizar el recuento mitótico. Multiplicando el número de mitosis por un factor de corrección, se obtiene el recuento mitótico estandarizado al área de referencia. Se han calculado los factores de corrección para los microscopios más habituales y para los diferentes tumores comunes. RESULTADOS Y CONCLUSIONES: Proponemos este método simple (únicamente uno por multiplicación) para estandarizar el recuento mitótico con respecto al área de referencia

Standardized Method for Defining a 1-mm2 Region of Interest for Calculation of Mitotic Rate on Melanoma Whole Slide Images.

CONTEXT.­: Mitotic rate counting is essential in pathologic evaluations in melanoma. The American Joint Committee on Cancer recommends reporting the number of mitotic figures (MFs) in a 1-mm2 area encompassing the "hot spot." There is currently no standard procedure for delineating a 1-mm2 region of interest for MF counting on a digital whole slide image (WSI) of melanoma. OBJECTIVE.­: To establish a standardized method to enclose a 1-mm2 region of interest for MF counting in melanoma based on WSIs and assess the method's effectiveness. DESIGN.­: Whole slide images were visualized using the ImageScope viewer (Aperio). Different monitors and viewing magnifications were explored and the annotation tools provided by ImageScope were evaluated. For validation, we compared mitotic rates obtained from WSIs with our method and those from glass slides with traditional microscopy with 30 melanoma cases. RESULTS.­: Of the monitors we examined, a 32-inch monitor with 3840 × 2160 resolution was optimal for counting MFs within a 1-mm2 region of interest in melanoma. When WSIs were viewed in the ImageScope viewer, ×10 to ×20 magnification during screening could efficiently locate a hot spot and ×20 to ×40 magnification during counting could accurately identify MFs. Fixed-shape annotations with 500 × 500-µm squares or circles can precisely and efficiently enclose a 1-mm2 region of interest. Our method on WSIs was able to produce a higher mitotic rate than with glass slides. CONCLUSIONS.­: Whole slide images may be used to efficiently count MFs. We recommend fixed-shape annotation with 500 × 500-µm squares or circles for routine practice in counting MFs for melanoma.

Adenoid cystic carcinoma with dedifferentiation/expansion of the luminal cell component and preserved biphasic morphology - Early high-grade transformation.

We present two patients (29 and 67 years) with histomorphologic and immunohistochemical evidence of early high-grade transformation of adenoid cystic carcinoma in the nasal cavity and floor of mouth, respectively. The component of early high-grade transformation was characterized by 1) selective expansion of the luminal (CK7+, c-kit+, p63-) cell component with severe cytologic atypia and significantly increased Ki-67 proliferation index, and 2) retained albeit attenuated abluminal (CK7-, c-kit-, p63+) cells, surrounding nests of high-grade luminal cells.

Reappraisal of the prognostic significance of mitotic rate supports its reincorporation into the melanoma staging system.

BACKGROUND: Mitotic rate is a strong, independent prognostic factor in patients with melanoma. However, incorporating it into the melanoma staging system has proved challenging. METHODS: The prognostic impact of mitotic rate was assessed in a melanoma cohort comprising 5050 patients from 2 geographically distinct populations. Computer-generated cut points for mitotic rate were constructed to determine its impact on melanoma-associated survival using Kaplan-Meier and multivariate regression analyses. The impact of mitotic rate also was assessed in randomly split training and validation sets. RESULTS: Mitotic rate had a nonlinear impact on survival, as evidenced by unequally spaced cut points. An index incorporating these cut points that was constructed from one population produced significantly more accurate predictions of survival in the other population than using the entire scale of mitotic rate. An index constructed from the combined cohort was found to be independently predictive of survival, with an impact comparable to that of ulceration. Optimal high-versus-low cut points for mitotic rate were generated separately for each T category (<2 mitoses/mm2 vs ≥2 mitoses/mm2 for T1 melanoma, <4 mitoses/mm2 vs ≥4 mitoses/mm2 for T2 melanoma, <6 mitoses/mm2 vs ≥6/mitoses/mm2 for T3 melanoma, and <7 mitoses/mm2 vs ≥7 mitoses/mm2 for T4 melanoma). Using Kaplan-Meier analysis, elevated mitotic rate was found to have an impact on survival comparable to that of ulceration within each T category. Application of the index for mitotic rate that was constructed from the training data set demonstrated an independent impact in the validation data set, with a significance similar to that of ulceration. CONCLUSIONS: The results of the current study demonstrated the comparable prognostic impact of mitotic rate and ulceration, providing support for its reincorporation into the T category.

Ki67 index and mitotic count: Correlation and variables affecting the accuracy of the quantification in endocrine/neuroendocrine tumors.

Quantification of Ki67 and mitosis is time consuming and subject to inter-observer variabilities. Limited studies explored the impact of those variables on the results and the correlation between mitotic count and Ki67 index in endocrine/neuroendocrine tumors, particularly so since the advent of PHH3 antibody and digital pathology. Using Ki67 and mitosis as examples, this study is intended to reveal variables affecting accurate quantification of biomarkers, and to explore the relationship of Ki67 index and mitotic count/index in endocrine/neuroendocrine tumors. Using both manual and pathologist supervised digital image analysis (PSDIA) methods, we examined the impact of post-analytical variables on the quantification of mitosis and Ki67 index and studied the correlation between them in 41 cases of endocrine/neuroendocrine tumors of variable histological grades/proliferating rates. We found that the selection of hotspots, field size and especially threshold affected the outcome of quantification of mitosis and Ki67 index; that mitotic count/index strongly (p < 0.05) correlated with Ki67 index only in the tumors with peak Ki67 index less than 30% and the correlation was more monotonic (positive, non-linear) than linear. In the hotspots of these tumors, the ratio of mitotic count to proliferating cells defined by Ki67 detection averaged 0.04. We also found that the PHH3 antibody could markedly increase the efficiency and accuracy of mitotic quantification. A consensus among pathologists is needed for the selection of hotspots, field size and threshold for quantification of mitosis and Ki67 index.

Comparison of different anti-Ki67 antibody clones and hot-spot sizes for assessing proliferative index and grading in pancreatic neuroendocrine tumours using manual and image analysis.

AIMS: Ki67 proliferative index (PI) is essential for grading gastroenteric and pancreatic neuroendocrine tumours (GEP NETs). Analytical and preanalytical variables can affect Ki67 PI. In contrast to counting methodology, until now little attention has focused on the question of clone equivalence and the effect of hot-spot size on Ki67 PI in GEP NETs. Using manual counting and image analysis, this study compared the Ki67 PI achieved using MM1, K2 and 30-9 to MIB1, a clone which has been validated for, and is referenced in, guidelines relating to assessment of Ki67 PI in GEP NETs. METHODS AND RESULTS: Forty-two pancreatic NETs were each immunohistochemically stained for the anti-Ki67 clones MIB1, MM1, K2 and 30-9. Ki67 PI was calculated manually and by image analysis, the latter using three different hot-spot sizes. In manual comparisons using single hot-spot high-power fields, non-MIB1 clones overestimated Ki67 PI compared to MIB1, resulting in grading discordances. Image analysis shows good agreement with manual Ki67 PI but a tendency to overestimate absolute Ki67 PI. Increasing the size of tumour hot-spot from 500 to 2000 cells resulted in a decrease in Ki67 PI. CONCLUSION: Different anti-Ki67 clones do not produce equivalent PIs in GEP NETs, and clone selection may therefore affect patient care. Increasing the hot-spot size decreases the Ki67 PI. Greater standardisation in terms of antibody clone selection and hot-spot size is required for grading GEP NETs. Image analysis is an effective tool for assisting Ki67 assessment and allows easier standardisation of the size of the tumour hot-spot.

Mitotic Index and Progression-Free Survival in Atypical Meningiomas.

Extent of resection and tumor grade are considered the most important predictors of progression-free survival (PFS) in meningiomas. However, adjuvant therapy for atypical meningiomas remains controversial, with variable PFS rates of up to 40%. The current mitotic index (MI) range for atypical meningiomas is broad, comprising all tumors with >4 and <20 mitotic count per 10 high-power fields, leading to substantial within-grade variation of recurrence risk, especially in borderline histologic cases, creating discordance between the clinical course and the application of the classification criteria. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a search of electronic databases from inception to July 2019 identified 121 articles for screening. After proper exclusion criteria, 7 articles were included for data extraction and analysis using meta-analysis of proportions. The MI was the variable of interest in the multivariate regressions and analyzed as a predictor of recurrence using hazard ratios (HRs) (95% confidence intervals). Separate random effect models were used for studies reporting the MI as a continuous or categorical variable. The pooled study results in this meta-analysis demonstrate a homogeneous statistically significant correlation between the MI and the rate of local recurrence after surgical resection regardless of the reporting method (continuous: HR = 1.20; categorical: HR = 2.65). However, significant limitations were noted, including the lack of a standardized method for MI calculation and heterogeneity of MI reports. We encourage the community to report their experience with the MI with greater precision and uniformity to further assess the influence of the MI on PFS within atypical meningiomas.

Interobserver Variability in Mitotic Count for Meningioma Grading: How Can We Reduce It?

AIM: To evaluate the interobserver variability in determining the number of mitoses in 10 high-power field (HPF) and thus the tumor grade, and to investigate how to reduce grade discordance between the observers and the most useful method to identify the patients who would receive an additional treatment. MATERIAL AND METHODS: Two hundred and seventy cases with meningioma were re-evaluated by three experienced pathologists and five senior residents. They determined the number of mitotic figures in 10 HPF in each slide. Re-evaluation of the cases, which were found of different grades from the reference observers was requested by full scan method. Statistical analysis was performed by using SPSS V23.0. RESULTS: A moderate agreement was found between the observers and the reference observer. After the evaluation of mitotic activity with the full scan method, the mean numbers of mitoses found by the observers in 10 HPF were increased. In the first evaluation, 4?6 cases were defined as Grade II by the observers. Whereas, 23?27 cases were defined as Grade II after the full scan method. CONCLUSION: If there are less than 16 mitotic figures throughout the slide, it is more difficult to find the 10 HPF including 4 or more mitosis. Interobserver variability in mitotic figure counting can be reduced by full scan method, and examining the hematoxylin and eosin stained slides by the full scan method helps us to determine the true histologic grade of meningiomas in most cases, who would receive an additional treatment.

Utility of PHH3 in Evaluation of Mitotic Index in Breast Carcinoma and Impact on Tumor Grade.

BACKGROUND: Mitotic activity index is considered as the most important grading component to predict prognosis in invasive breast carcinoma. But it is believed that it is also the cause of discordance in grade estimation based on Bloom-Richardson system. Thus, reproducible methods such as immunohistochemistry (IHC) based analysis methods appears to be of great value in facilitating mitotic count. MATERIALS AND METHODS: In the present study, we examined the utility of Phosphohistone H3 by IHC in various grades of breast carcinoma and compared it with traditional mitotic count by hematoxylin and eosin (H and E) staining and probable changes in tumor grading. RESULTS: Total 90 cases of invasive breast carcinoma were evaluated. Mean mitotic count were 8.6 and 6.4/10HPF in IHC and HandE groups, respectively. Although , mean average count was higher by IHC method , good correlation was observed(R=0.914). Using PHH3 IHC, two out of 33 cases of grade I tumors were upgraded in to grade II and three cases of grade II were upgraded in to grade III. None of the tumors were down graded. CONCLUSION: Similar to some other previous studies, we found PHH3 a robust sensitive and practical marker for mitotic count in breast carcinoma. Especially it is helpful to identify the most proliferating area. However, further studies are required to confirm the superiority of this biomarker for including in grading system.
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The investigation of the in vivo cytogenetic effects of psychotropic drugs in human lymphocyte cultures.

The connection of nearly all current antipsychotic drugs to their in vivo cytogenetic activity has not been yet fully investigated. Fluvoxamine, Valproic acid (VA) and Haloperidol (HLP) are three universally common consumed psychotic drugs whereas used to treat several psychiatric disorders. This study aims to investigate the cytogenetic effects of these three psychotropic drugs by evaluating the frequency of Sister Chromatid Exchanges (SCEs) and the Proliferation Rate Index (PRI) in cultured lymphocytes. Fifteen patients with psychiatric disorders (i.e. depression, bipolar and schizophrenia) consisting of smokers and non-smokers were included. Estimation of SCEs was used as a sensitive biomarker of the potential cytotoxicity, while PRI was used as a valuable marker of cytostatic activity. A significant increase of SCEs in the cultured lymphocyte of the smoker controls (P= 0.013) was found in compared to the non-smoker controls. This study found that there is no difference in the average of SCEs values in lymphocytes isolated from the smoker and non-smoker patients treated with Fluvoxamine, Valproic acid and Haloperidol (P> 0.05). A significant difference of PRI (P= 0.036) in the lymphocytes of smoker controls compared to those of the non-smoker controls were detected. This study also found a significant difference with respect to PRI between the three patient groups (P= 0.017). These results illustrated that treatment (monotherapy) of psychiatric patients with Fluvoxamine, Valproic acid, and Haloperidol exerts a significant cytostatic but not cytotoxic effect on their lymphocytes whereas these effects are intensified by smoking.

Global and mitosis-specific interobserver variation in mitotic count scoring and implications for malignant melanoma staging.

AIMS: Staging is the gold standard for predicting malignant melanoma outcome but changes in its criteria over time indicate ongoing evolution. One notable recent change from the 8th edition of the American Joint Committee on Cancer (AJCC) staging manual was removal of mitotic count. We explore the extent to which this feature is limited by interobserver error in order to find ways to improve its fitness for use should it be revisited in future staging versions. METHODS AND RESULTS: In a cohort of 476 patients with melanoma ≤1.0 mm, a mitotic count of 0 versus 1 was significant for metastasis-free survival, but not melanoma-specific or overall survival. In 10 melanomas that were 0.9-1.0 mm thick, the mitotic count intraclass correlation coefficient for histopathologists was 0.58 (moderate agreement). Uniquely, we also assessed agreement for specific putative mitotic figures, identifying precise reasons why specific mitotic figures qualified for scoring or elimination. A kappa score was 0.54 (moderate agreement). We also gathered data on other staging features. Breslow thickness had an intraclass correlation coefficient of 0.41 (moderate agreement) and there was a systematic difference between histopathologists among cases (P = 0.04). Every case had a range that crossed the AJCC8 0.8-mm pT1a/pT1b staging boundary. Ulceration was only identified in two of the 10 cases. For ulceration, kappa agreement score was 0.31 (fair). CONCLUSION: This study supports the removal of mitotic count from staging, but shows that its scoring is substantially affected by interobserver variation, suggesting that more prescriptive guidelines might have a beneficial impact on its prognostic value.

Correlation Between Digital and Manual Determinations of Ki-67/MIB-1 Proliferative Indices in Human Meningiomas.

Objective. Proliferative activity in tumor tissues is assessed as the percentage of Ki-67/MIB-1-positive cells, or the proliferative index (PI). The PI is routinely assessed manually. However, the subjectivity of manual assessments might result in poor reproducibility. We hypothesized that digital assessments might reduce the error. Method. In our study, we assessed Ki-67/MIB-1 PIs, both manually and digitally, with tissue microarrays constructed from 141 human meningioma samples. Spearman-rank correlation and κ statistics were applied for correlation and agreement analyses, respectively. Mann-Whitney U tests were used to compare MIB-1 PIs between groups. Prognostic ability was assessed with Kaplan-Meier and Cox regression analyses. Results. We found a significant, high correlation (Spearman ρ = 0.832, P < .01) and moderate agreement (κ coefficient = 0.617, observed agreement = 80.9%) between the 2 methods. Both methods found significantly different Ki-67/MIB-1 PIs for different World Health Organization grades (P < .05). Neither method showed significant prognostic value. Conclusion. Digital determinations of Ki-67/MIB-1 PIs in human meningiomas are feasible for the daily routine.