Subgrading of G2 Pancreatic Neuroendocrine Tumors as 2A (Ki67 3% to < 10%) Versus 2B (10% to ≤ 20%) Identifies Behaviorally Distinct Subsets in Keeping with the Evolving Management Protocols.

BACKGROUND: Grade 1/2 PanNETs are mostly managed similarly, typically without any adjunct treatment with the belief that their overall metastasis rate is low. In oncology literature, Ki67-index of 10% is increasingly being used as the cutoff in stratifying patients to different protocols, although there are no systematic pathology-based studies supporting this approach. METHODS: Ki67-index was correlated with clinicopathologic parameters in 190 resected PanNETs. A validation cohort (n = 145) was separately analyzed. RESULTS: In initial cohort, maximally selected rank statistics method revealed 12% to be the discriminatory cutoff (close to 10% rule of thumb). G2b cases had liver/distant metastasis rate of almost threefold higher than that of G2a and showed significantly higher frequency of all histopathologic signs of aggressiveness (tumor size, perineural/vascular invasion, infiltrative growth pattern, lymph node metastasis). In validation cohort, these figures were as striking. When all cases were analyzed together, compared with G1, the G2b category had nine times higher liver/distant metastasis rate (6.1 vs. 58.5%; p < 0.001) and three times higher lymph node metastasis rate (20.5 vs. 65.1%; p < 0.001). CONCLUSIONS: G2b PanNETs act very similar to G3, supporting management protocols that regard them as potential therapy candidates. Concerning local management, metastatic behavior in G2b cases indicate they may not be as amenable for conservative approaches, such as watchful waiting or enucleation. This substaging should be considered into diagnostic guidelines, and clinical trials need to be devised to determine the more appropriate management protocols for G2b (10% to ≤ 20%) group, which shows liver/distant metastasis in more than half of the cases, which at minimum warrants closer follow-up.

Prediction of Oncotype DX Recurrence Score Based on Systematic Evaluation of Ki-67 Scores in Hormone Receptor-Positive Early Breast Cancer.

PURPOSE: Oncotype DX (ODX) predicts the risk of recurrence and benefits of adding chemotherapy for patients with estrogen receptor positive (ER+)/human epidermal growth factor receptor 2 negative (HER2-) early-stage breast cancer. We aimed to develop a simplified scoring system using readily available clinicopathological parameters to predict a high-risk ODX recurrence score (RS) while minimizing reproducibility issues regarding Ki-67 index evaluation methods. METHODS: We enrolled 300 patients with ER+/HER2- early breast cancer, for whom ODX RS data were available in the test set. Using the QuPath image analysis platform, we systematically evaluated the average, hotspot, and hottest spot Ki-67 scores in the test set. Logistic regression analyses were conducted to establish a predictive scoring system for high-risk ODX RS. An independent validation set comprising 117 patients over different periods was established. RESULTS: Factors such as age ≤ 50 years, invasive ductal carcinoma tumor type, histologic grade 2 or 3, tumor necrosis, progesterone receptor negativity, and a high Roche-analyzed Ki-67 score (> 20) were associated with high-risk ODX RS. These variables were incorporated into our scoring system. The area under the curve of the scoring system was 0.8057. When applied to both the test and validation sets with a cutoff value of 3, the sensitivity of our scoring system was 92%. CONCLUSION: We successfully developed a scoring system based on the systematic evaluation of Ki-67 scoring methods. We believe that our user-friendly predictive scoring system for high risk ODX RS could help clinicians in identifying patients who may or may require additional ODX testing.

Optimizing the use of Ki-67 proliferative index as a prognostic biomarker in meningiomas using digital analysis.

OBJECTIVE: Ki-67 immunohistochemistry is widely used as a prognostic marker in meningiomas, but visual estimations tend to be imprecise. Whether the average Ki-67 over an entire slide, a particular block, or areas of high staining (hotspots) is prognostic for recurrence-free survival (RFS) and overall survival (OS) is unknown. This study aimed to generate evidence-based recommendations for the optimal use of Ki-67 immunohistochemistry in the workup of meningiomas. METHODS: All tissue blocks from a retrospective cohort of 221 patients with primary meningioma (141 WHO grade 1, 64 WHO grade 2, 16 WHO grade 3) were immunostained for Ki-67 and scanned using automated digital analysis software. QuPath was used to quantify the average Ki-67 proliferation index per slide as well as the Ki-67 hotspot in a 2.2-mm2 area within each slide. The best block was defined subjectively by a neuropathologist as the most representative tissue block from each case. The pathology report Ki-67 was determined by visual estimation. Age, sex, WHO grade, extent of resection, tumor location, and quantitative Ki-67 labeling were tested to determine risk factors for RFS and OS. RESULTS: Multivariable analyses demonstrated that WHO grade 2 (HR 2.42, p = 0.018), subtotal resection (HR 8.16, p < 0.0001), near-total resection (HR 2.24, p = 0.041), QuPath Ki-67 averaged across all blocks (HR per % increase = 1.72, p = 0.030), and pathology report Ki-67 (HR per % increase = 1.05, p = 0.0026) were associated with shorter RFS. The average Ki-67 in the best block, maximum across all slides, and maximum hotspot in the best block were not associated with RFS. Only male sex was independently associated with shorter OS (HR 8.52, p = 0.0003). The pathology report Ki-67 was, on average, 6.5 times higher than the QuPath average. CONCLUSIONS: These data on Ki-67 in meningiomas indicate the following: 1) visual estimation substantially overestimates Ki-67, 2) digital quantification of average Ki-67 across all tissue blocks provides more prognostic information than small hotspot regions or an entire single block, and 3) Ki-67 is not informative for OS. The results suggest that best practices for incorporating Ki-67 into meningioma prognostication include digital quantification of average Ki-67 over multiple blocks.

Prognostic heterogeneity of Ki67 in non-small cell lung cancer: A comprehensive reappraisal on immunohistochemistry and transcriptional data.

In the present study, the debatable prognostic value of Ki67 in patients with non-small cell lung cancer (NSCLC) was attributed to the heterogeneity between lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC). Based on meta-analyses of 29 studies, a retrospective immunohistochemical cohort of 1479 patients from our center, eight transcriptional datasets and a single-cell datasets with 40 patients, we found that high Ki67 expression suggests a poor outcome in LUAD, but conversely, low Ki67 expression indicates worse prognosis in LUSC. Furthermore, low proliferation in LUSC is associated with higher metastatic capacity, which is related to the stronger epithelial-mesenchymal transition potential, immunosuppressive microenvironment and angiogenesis. Finally, nomogram model incorporating clinical risk factors and Ki67 expression outperformed the basic clinical model for the accurate prognostic prediction of LUSC. With the largest prognostic assessment of Ki67 from protein to mRNA level, our study highlights that Ki67 also has an important prognostic value in NSCLC, but separate evaluation of LUAD and LUSC is necessary to provide more valuable information for clinical decision-making in NSCLC.

Peer-to-peer validation of Ki-67 scoring in a pathology quality circle as a tool to assess interobserver variability: are we better than we thought?

Ki-67, a nuclear protein expressed in all stages of cellular proliferation, is a valuable tool to assess tumor proliferation and has been linked to more aggressive tumor behavior. However, interlaboratory staining heterogeneity and inter-observer variability challenge its reproducibility. Round Robin tests are a suitable tool to standardize and harmonize immunohistochemical and molecular analyses in histopathology. The study investigates the interrater and interlaboratory reproducibility of Ki-67-scoring using both manual and automated approaches. Unstained TMA slides comprising diverse tumor types (breast cancer, neuroendocrine tumors, lymphomas, and head and neck squamous cell carcinoma) were distributed to six pathology laboratories, each employing their routine staining protocols. Manual and automated scoring methods were applied, and interrater and interlaboratory agreement assessed using intraclass correlation coefficients (ICC). The results highlight good-to-excellent reliability overall, with automated scoring demonstrating higher consistency (ICC 0.955) than manual scoring (ICC 0.871). Results were more variable when looking at the individual entities. Reliability remained good for lymphomas (ICC 0.878) and breast cancer (ICC 0.784) and was poor in well-differentiated neuroendocrine tumors (ICC 0.354). This study clearly advocates standardized practices and training to ensure consistency in Ki-67-assessment, and it demonstrates that this can be achieved in a peer-to-peer approach in local quality-circles.

Morphological Signatures of Neurogenesis and Neuronal Migration in Hypothalamic Vasopressinergic Magnocellular Nuclei of the Adult Rat.

The arginine vasopressin (AVP)-magnocellular neurosecretory system (AVPMNS) in the hypothalamus plays a critical role in homeostatic regulation as well as in allostatic motivational behaviors. However, it remains unclear whether adult neurogenesis exists in the AVPMNS. By using immunoreaction against AVP, neurophysin II, glial fibrillar acidic protein (GFAP), cell division marker (Ki67), migrating neuroblast markers (doublecortin, DCX), microglial marker (Ionized calcium binding adaptor molecule 1, Iba1), and 5'-bromo-2'-deoxyuridine (BrdU), we report morphological evidence that low-rate neurogenesis and migration occur in adult AVPMNS in the rat hypothalamus. Tangential AVP/GFAP migration routes and AVP/DCX neuronal chains as well as ascending AVP axonal scaffolds were observed. Chronic water deprivation significantly increased the BrdU+ nuclei within both the supraaoptic (SON) and paraventricular (PVN) nuclei. These findings raise new questions about AVPMNS's potential hormonal role for brain physiological adaptation across the lifespan, with possible involvement in coping with homeostatic adversities.

Evaluation of immunophenotype and inflammation in canine mammary neoplasms with solid arrangement.

Morphological and immunohistochemical studies of solid arrangement canine mammary carcinomas have shown that the different histological types may be characterized by proliferation of epithelial and/or myoepithelial cells. However, little is known about immunophenotypes and the importance of inflammation as prognostic factors in these neoplasms. The objective of the present study was to characterize the immunophenotype and degree of inflammation in the solid type of canine mammary neoplasm and to investigate their association with metastasis, Ki-67 index, tumour size, necrosis and survival. Sixty-five carcinomas with solid pattern, basaloid carcinomas, solid papillary carcinomas, malignant adenomyoepitheliomas (MAMEs) or malignant myoepitheliomas (MMEs) were investigated. Luminal A, luminal B HER2 negative and HER2 positive, HER2 overexpressed and triple negative immunophenotypes were immunolabelled as were Ki-67 protein and cyclooxygenase-2 (Cox-2). Histological peritumoural and intratumoural inflammatory infiltrates were graded (distribution × intensity) and the presence of necrosis identified. We found a statistical difference between histological types and immunophenotypes, with MME and MAME having a higher occurrence of luminal A, whereas most neoplasms had the luminal B HER-negative immunophenotype. There was no correlation between immunophenotype and degree of peri- and intratumoural inflammation, nodal metastasis, necrosis or tumour size. An increased degree of peri- and intratumoural inflammation was significantly associated with lymph node metastasis, and more severe intratumoural inflammation was associated with the presence of tumour necrosis. Tumour size, Ki-67 index and Cox-2 score were not associated with inflammation in either peri- or intratumoural regions. No difference was observed in survival in relation to immunophenotype or degree of inflammation, but the Cox regression model revealed that nodal metastasis influenced the risk of death.

MRI-based radiomics signatures for preoperative prediction of Ki-67 index in primary central nervous system lymphoma.

PURPOSE: The aim of this study was to develop and validate radiomics signatures based on MRI for preoperative prediction of Ki-67 proliferative index (PI) expression in primary central nervous system lymphoma (PCNSL). METHODS: A total of 341 patients with PCNSL were retrospectively analyzed, including 286 patients in one center as the training set and 55 patients in another two centers as the external validation set. Radiomics features were extracted and selected from preoperative contrast-enhanced T1-weighted images, fluid attenuation inversion recovery to build radiomics signatures according to the Ki-67 PI. The predictive performances of the radiomics model were evaluated using four classifiers including random forest, K-Nearest Neighbors, Neural Network and Decision Tree. A combined model was built by incorporating radiomics signature, clinical variables and MRI radiological characteristics using multivariate logistic regression analysis, and a nomogram was established to predict the expression of Ki-67 individually. The predictive performances of the models were evaluated using area under receiver operating characteristic curve (AUC) and decision curve analysis (DCA). RESULTS: Radiomics signatures were independent predictors of the expression level of Ki-67 (OR: 2.523, P < 0.001). RF radiomics models had the highest accuracy (0.934 in the training set and 0.811 in the external validation set) and F1 Score (0.920 in the training set and 0.836 in the external validation set). The clinic-radiologic-radiomics nomogram showed better predictive performance with AUCs of 0.877(95 % CI: 0.837-0.918) in the training set and 0.866(95 % CI: 0.774-0.957) in the external validation set. The calibration curve and DCA demonstrated goodness-of-fit and improved benefits in clinical practice of the nomogram. CONCLUSIONS: Nomograms integrating MRI-based radiomics and clinical-radiological characteristics could effectively predict Ki-67 PI in primary PCNSL.

[Quantification of Ki-67 in PitNET (pituitary neuroendocrine tumors)/adenomas]. / Quantifizierung von Ki-67 in PitNET ("pituitary neuroendocrine tumors")/Adenomen.

This study is the first to compare the determination of the Ki-67 index in pituitary neuroendocrine tumors (PitNET)/pituitary adenomas by pathologists with a computerized method (Cognition MasterSuite from VMScope, Berlin, Germany). PitNET/pituitary adenomas often show a low proliferation index. Observer variability is high, especially when estimating in this low percentage range. A more reliable determination would be possible using the four-eyes principle, but this cannot be realized continuously; thus, digital image analysis is a promising solution. In the study, there was clear agreement between the Ki-67 estimate by two experienced pathologists and the determination with the aid of digital image analysis. The digital image analysis system is excellent for determining the proliferation rate of PitNET/pituitary adenomas and can therefore be used to determine the "third" and "fourth eye".

Outcome of non-functioning ACTH pituitary tumors: silent does not mean indolent.

INTRODUCTION: Silent corticotroph tumors (siACTH) represent a rare entity of pituitary tumors (PT), usually more aggressive than other PT. Few predictor factors of recurrence in the post-operative period have been proposed until now. This study aimed (1) to evaluate the clinical outcome of siACTH after surgery according to a five-tiered clinicopathological classification (2) to compare siACTH characteristics to ACTH-secreting macroadenomas (macroCD), and silent gonadotropinomas (siLH/FSH). PATIENTS AND METHODS: Between 2008 and 2022, 29 siACTH out of 865 PT cases operated in one tertiary center were included. Clinical, paraclinical, histological, and surgical data were collected and compared to 25 macroCD and 143 siLH/FSH cases, respectively. The tumor grading was established according to both invasion (no = 1; yes = 2) and proliferation (no = a; yes = b). Progression-free survival was estimated using Kaplan-Meier method and log-rank test. RESULTS: We identified 15 (51.7%) grade 1a, 11 (37.9%) grade 2a and 3 (10.3%) grade 2b siACTH with a trend for a 7-fold-time higher risk of progression/recurrence in grade 2b as compared to 1a (p = 0.06). The repartition of tumor grades was similar between the three subgroups, however a 5.7-fold-higher risk of progression was observed in grade 1a siACTH than in grade 1a siLH/FSH (p = 0.02). Compared to siLH/FSH, higher ACTH levels may help to preoperatively identify siACTH. CONCLUSION: The five-tiered clinicopathological classification contribute to predict the risk of recurrence of operated siACTH tumors. Noteworthy, non-invasive and non-proliferative siACTH exhibit a less favorable outcomes than their siLH/FSH counterparts, which should prompt for a personalized follow up.

Immunohistochemistry staining of Eag1 and p16/Ki-67 can help improve the management of patients with cervical intraepithelial Neoplasia after cold knife conversion.

BACKGROUND: Immunohistochemistry (IHC) is widely used in the management of patients with cervical intraepithelial neoplasia (CIN) but still has many limitations in clinical practice. We analyzed the correlation of new biomarkers with the severity of CIN and follow-up outcomes in patients after conization to improve the management of patients with CIN. METHODS: IHC staining of Eag1 and p16/Ki-67 was performed on cervical tissue sections from 234 patients with suspected CIN2/3. After a series of follow-ups, including human papillomavirus (HPV) test and thinprep cytologic test (TCT) for 1-2 years, the outcomes were collected. IHC scores of biomarkers and follow-up results were used to analyze the correlation and assess the diagnostic efficiency of biomarkers. RESULTS: The IHC staining intensity of Eag1 and p16/Ki-67 was significantly different from that of the CIN1-3 groups (p < 0.05). Eag1 expression scores were significantly different in the distribution between the two follow-up groups (p < 0.001). ROC curves based on the correlations between the follow-up outcomes and the Eag1 scores and IS of p16/ki-67 showed that Eag1 had a greater AUC (0.767 vs. 0.666). Logistic regression analysis of the combination of biomarkers revealed a greater AUC value than any single biomarker. CONCLUSIONS: Eag1 expression was significantly correlated with CIN grade and follow-up outcomes after conization. IHC staining of combinations of biomarkers of Eag1, p16 and Ki-67 may help us to improve the ability to identify risk groups with abnormal follow-up outcomes after treatment for CIN.

MRI radiomics-based interpretable model and nomogram for preoperative prediction of Ki-67 expression status in primary central nervous system lymphoma.

Objectives: To investigate the value of interpretable machine learning model and nomogram based on clinical factors, MRI imaging features, and radiomic features to predict Ki-67 expression in primary central nervous system lymphomas (PCNSL). Materials and methods: MRI images and clinical information of 92 PCNSL patients were retrospectively collected, which were divided into 53 cases in the training set and 39 cases in the external validation set according to different medical centers. A 3D brain tumor segmentation model was trained based on nnU-NetV2, and two prediction models, interpretable Random Forest (RF) incorporating the SHapley Additive exPlanations (SHAP) method and nomogram based on multivariate logistic regression, were proposed for the task of Ki-67 expression status prediction. Results: The mean dice Similarity Coefficient (DSC) score of the 3D segmentation model on the validation set was 0.85. On the Ki-67 expression prediction task, the AUC of the interpretable RF model on the validation set was 0.84 (95% CI:0.81, 0.86; p < 0.001), which was a 3% improvement compared to the AUC of the nomogram. The Delong test showed that the z statistic for the difference between the two models was 1.901, corresponding to a p value of 0.057. In addition, SHAP analysis showed that the Rad-Score made a significant contribution to the model decision. Conclusion: In this study, we developed a 3D brain tumor segmentation model and used an interpretable machine learning model and nomogram for preoperative prediction of Ki-67 expression status in PCNSL patients, which improved the prediction of this medical task. Clinical relevance statement: Ki-67 represents the degree of active cell proliferation and is an important prognostic parameter associated with clinical outcomes. Non-invasive and accurate prediction of Ki-67 expression level preoperatively plays an important role in targeting treatment selection and patient stratification management for PCNSL thereby improving prognosis.

Immunohistochemical Expression of Ki-67 and p53 and Their Prognostic Role in Ameloblastoma: A Longitudinal Study.

Objectives: Ameloblastoma, comprising approximately 11% of all odontogenic tumors, is a locally aggressive tumor with a high recurrence rate. This study aimed to assess the immunohistochemical expression of Ki-67 and p53 and their association with clinical and pathological factors among patients with ameloblastoma. Methods: Retrospective follow-up data of patients histologically confirmed with ameloblastoma at Makerere College of Health Sciences in Kampala, Uganda from January 2012 to December 2018 were retrieved. Factors associated with Ki-67 and p53 immunohistochemical expression were determined using one-way one-way analysis of variance. Chi-square and Fisher's exact statistical tests were used to assess factors associated with recurrence. A two-tailed p < 0.05 was considered statistically significant. Results: A total of 40 patients confirmed histologically with ameloblastoma were included in the analysis. The majority (62.5%) of cases were of the conventional type of ameloblastoma. The expressions of Ki-67 and p53 were 52.5% and 85.0%, respectively. Recurrence was found in 47.5% of patients and it was associated with conventional histological type (p=0.042), segmental resection (p < 0.001), tumor size (p < 0.001), and high p53 expression (p=0.041). Conclusions: Almost half the cases in this study had recurrence. The immunohistochemical expression of p53 was significantly higher than that of Ki-67.

Assessment of Ki-67 and mitoses in pituitary neuroendocrine tumours-Consistency counts.

Pituitary neuroendocrine tumour Ki-67 proliferation index varies according to the number of tumour cells assessed. Consistent Ki-67 scoring approaches and re-evaluation of the recommended Ki-67 3% cut-off are required to clarify controversies in pituitary neuroendocrine tumour Ki-67 proliferation index assessment.

Clinical Pathological and Immunohistochemical Correlations in Gastric Cancer.

Due to its high aggressiveness and polyclonal tumor state, stomach cancer is considered a severe health problem. In this study, we analyzed Her2 and Ki67 in correlation with patient data for the possibility of prognostic factors. The study included 48 cases of gastric tumors that had been surgically treated in a period of five years. The percentage was statistically significant for intestinal-type adenocarcinomas located in the medio-gastric region (p = 0.05); in the diffuse subtype, there were no Her2 positive samples, and in the mixed subtype only one out of three samples was Her2 positive. Our results confirm the existing data, and we can conclude that this link can be considered a prognostic factor in the progression and treatment effectiveness.

The Diagnostic Accuracy of Electrical Impedance Spectroscopy-Assisted Colposcopy, HPV mRNA Test, and P16/Ki67 Immunostaining as CIN2+ Predictors in Greek Population.

OBJECTIVE: To evaluate the diagnostic accuracy of Electrical Impedance Spectroscopy (EIS)-assisted colposcopy in detecting CIN2+ Greek women towards standalone colposcopy, HPV mRNA testing, and p16/Ki67 immunostaining. METHODS: We conducted a cross-sectional observational study at the Cervical Pathology Clinic of the 2nd Obstetrics-Gynecology University Department of Hippokration Hospital Thessaloniki involving 316 patients from January 2022 to August 2023. All participants provided liquid-based cervical samples for cytology, HPV mRNA testing, and p16/Ki67 immunostaining. MAIN OUTCOME MEASURES: Subsequently, participants underwent both standalone colposcopy and EIS/ZedScan-assisted colposcopy, followed by cervical punch biopsies. RESULTS: The incorporation of EIS significantly enhanced the sensitivity of colposcopy, increasing it from 54.17% to 100%, equivalent to that of HPV mRNA testing and p16/Ki67 immunostaining, while achieving a high specificity (95.45%). The specificities observed with EIS/ZedScan-assisted and standalone colposcopy were notably superior to those of HPV-related biomarkers (HPV mRNA test and p16/Ki67 immunostaining). When compared to standalone colposcopy, HPV mRNA testing, and p16/Ki67 immunostaining, EIS/ZedScan-assisted colposcopy demonstrated the most favorable combination of Positive and Negative Predictive Values, at 90.57% and 100%, respectively. The inclusion of EIS/ZedScan in colposcopy led to the detection of 44 additional cases of true CIN2+ (100% of the total CIN2+ confirmed histologically) that were missed by standalone colposcopy. This discovery suggests a 45.83% increase in the detection of CIN2+ cases. CONCLUSIONS: The integration of EIS with colposcopy has demonstrated effectiveness in detecting cervical lesions, resulting in a significant detection increase of CIN2+ cases while offering optimal levels of sensitivity, specificity, and predictive values for CIN2+ detection.

PP2A-B55 phosphatase counteracts Ki-67-dependent chromosome individualization during mitosis.

Cell cycle progression is regulated by the orderly balance between kinase and phosphatase activities. PP2A phosphatase holoenzymes containing the B55 family of regulatory B subunits function as major CDK1-counteracting phosphatases during mitotic exit in mammals. However, the identification of the specific mitotic roles of these PP2A-B55 complexes has been hindered by the existence of multiple B55 isoforms. Here, through the generation of loss-of-function genetic mouse models for the two ubiquitous B55 isoforms (B55α and B55δ), we report that PP2A-B55α and PP2A-B55δ complexes display overlapping roles in controlling the dynamics of proper chromosome individualization and clustering during mitosis. In the absence of PP2A-B55 activity, mitotic cells display increased chromosome individualization in the presence of enhanced phosphorylation and perichromosomal loading of Ki-67. These data provide experimental evidence for a regulatory mechanism by which the balance between kinase and PP2A-B55 phosphatase activity controls the Ki-67-mediated spatial organization of the mass of chromosomes during mitosis.

Qualitative and quantitative MRI analysis of alveolar soft part sarcoma: correlation with histological grade and Ki-67 expression.

OBJECTIVE: To investigate the correlation between MRI findings and histological features for preoperative prediction of histological grading and Ki-67 expression level in alveolar soft part sarcoma (ASPS). METHODS: A retrospective analysis was conducted on 63 ASPS patients (Jan 2017-May 2023). All patients underwent 3.0-T MRI examinations, including conventional sequences, dynamic contrast-enhanced scans with time-intensity curve analysis, and diffusion-weighted imaging with apparent diffusion coefficient (ADC) measurements. Patients were divided into low-grade (histological Grade I) and high-grade (histological Grade II/III) groups based on pathology. Immunohistochemistry was used to assess Ki-67 expression levels in ASPS. Statistical analysis included chi-square tests, Wilcoxon rank-sum test, binary logistic regression analysis, Spearman correlation analysis, and receiver operating characteristic curve analysis of various observational data. RESULTS: There were 29 low-grade and 34 high-grade patients (26 males and 37 females) and a wide age range (5-68 years). Distant metastasis, tumor enhancement characteristics, and ADC values were independent predictors of high-grade ASPS. High-grade ASPS had lower ADC values (p = 0.002), with an area under the curve (AUC), sensitivity, and specificity of 0.723, 79.4%, and 58.6%, respectively, for high-grade prediction. There was a negative correlation between ADC values and Ki-67 expression (r = -0.526; p < 0.001). When the cut-off value of ADC was 0.997 × 10-3 mm²/s, the AUC, sensitivity, and specificity for predicting high Ki-67 expression were 0.805, 65.6%, and 83.9%, respectively. CONCLUSION: Qualitative and quantitative MRI parameters are valuable for predicting histological grading and Ki-67 expression levels in ASPS. CRITICAL RELEVANCE STATEMENT: This study will help provide a more nuanced understanding of ASPS and guide personalized treatment strategies. KEY POINTS: There is limited research on assessing ASPS prognosis through MRI. Metastasis, enhancement, and ADC correlated with histological grade; ADC related to Ki-67 expression. MRI provides clinicians with valuable information on ASPS grading and proliferation activity.

CENPF May Act as a Novel Marker and Highlight the Influence of Pericyte in Infantile Hemangioma.

Infantile hemangioma (IH), a benign microvascular tumor, is marked by early and extensive proliferation of immature hemangioma endothelial cells (Hem-ECs) that naturally regress through differentiation into fibroblasts or adipocytes. However, a challenge persists, as the unique biological behavior of IH remains elusive, despite its general sensitivity to propranolol treatment. Recent evidence suggests that abnormal volume proliferation in IH is primarily attributed to the accumulation of hemangioma pericytes (Hem-Pericytes), in addition to Hem-ECs. Centromere protein F (CENPF) is involved in regulating mitotic processes and has been associated with malignant tumor cell proliferation. It is a key player in maintaining genomic stability during cell division. Our findings revealed specific expression of CENPF in Hem-Pericytes, with a proliferation index (PI) approximately half that of Ki67 (3.28 vs 6.97%) during the proliferative phase of IH. This index decreased rapidly in the involuting phase (P < .05), suggesting that the contribution of pericytes to IH development was comparable to that of Hem-ECs. Tumor expansion and shrinkage may be due to the proliferation, reduction, and differentiation of Hem-Pericytes. In conclusion, we speculate CENPF as a novel marker for clinical pathological diagnosis and a potential therapeutic target, fostering advancements in drug development.

Assessment of the current and emerging criteria for the histopathological classification of lung neuroendocrine tumours in the lungNENomics project.

BACKGROUND: Six thoracic pathologists reviewed 259 lung neuroendocrine tumours (LNETs) from the lungNENomics project, with 171 of them having associated survival data. This cohort presents a unique opportunity to assess the strengths and limitations of current World Health Organization (WHO) classification criteria and to evaluate the utility of emerging markers. PATIENTS AND METHODS: Patients were diagnosed based on the 2021 WHO criteria, with atypical carcinoids (ACs) defined by the presence of focal necrosis and/or 2-10 mitoses per 2 mm2. We investigated two markers of tumour proliferation: the Ki-67 index and phospho-histone H3 (PHH3) protein expression, quantified by pathologists and automatically via deep learning. Additionally, an unsupervised deep learning algorithm was trained to uncover previously unnoticed morphological features with diagnostic value. RESULTS: The accuracy in distinguishing typical from ACs is hampered by interobserver variability in mitotic counting and the limitations of morphological criteria in identifying aggressive cases. Our study reveals that different Ki-67 cut-offs can categorise LNETs similarly to current WHO criteria. Counting mitoses in PHH3+ areas does not improve diagnosis, while providing a similar prognostic value to the current criteria. With the advantage of being time efficient, automated assessment of these markers leads to similar conclusions. Lastly, state-of-the-art deep learning modelling does not uncover undisclosed morphological features with diagnostic value. CONCLUSIONS: This study suggests that the mitotic criteria can be complemented by manual or automated assessment of Ki-67 or PHH3 protein expression, but these markers do not significantly improve the prognostic value of the current classification, as the AC group remains highly unspecific for aggressive cases. Therefore, we may have exhausted the potential of morphological features in classifying and prognosticating LNETs. Our study suggests that it might be time to shift the research focus towards investigating molecular markers that could contribute to a more clinically relevant morpho-molecular classification.