The Impact of Phosphohistone-H3-Assisted Mitotic Count and Ki67 Score in the Determination of Tumor Grade and Prediction of Distant Metastasis in Well-Differentiated Pancreatic Neuroendocrine Tumors

Anti-phosphohistone H3 (PHH3) as a proliferation marker to assess mitotic activity and to grade neuroendocrine neoplasms of hepatopancreaticobiliary (HPB) system

BACKGROUND

The world health organization (WHO) classification of neuroendocrine neoplasms (NENs, i.e. neuroendocrine tumors (NETs) and neuroendocrine carcinomas (NECs)) of the gastrointestinal system involves grading of these tumors by mitotic count (i.e. H and E mitotic index or Haematoxylin and Eosin mitotic index [HE-MI] and Mindbomb E3 ubiquitin protein ligase 1 labelling index (MIB1-LI) into Grade 1 (G1), Grade 2 (G2), or Grade 3 (G3). However, the assessment of HE-MI and MIB1-LI is hindered by several factors that contribute to discordance between these two grading methods. Clinical data demonstrate the dependency of prognosis on grade.

OBJECTIVES

The objective of this study was to compare the grading of NENs of the hepatopancreatobiliary (HPB) system using Anti-phosphohistone H3 mitotic index (i.e. PHH3-MI), HE-MI and MIB1-LI.

MATERIALS AND METHODS

In a cohort of 140 NENs selected from January 2011 to August 2019, the concordance and correlation between HE-MI, MIB1-LI and PHH3-MI grading methods were analysed using Cohen's weighted kappa ( κ ) statistics and Spearman's correlation (ρ), respectively. Receiver operating characteristic (ROC) curve and cut-off analyses were done to determine optimal PHH3-MI cut-off values to grade NENs.

RESULTS

The rates of discordance between HE-MI vs. MIB1-LI, PHH3-MI vs. MIB1-LI and PHH3-MI vs. HE-MI were 52% ( κ =0.416), 29% ( κ =0.64) and 41% ( κ =0.508), respectively. There was a significant correlation between the grading methods. PHH3-MI had good overall sensitivity and specificity at cut-offs 2 and 17 in distinguishing between G1 vs. G2, and G2 vs. G3 tumors, respectively.

CONCLUSION

PHH3 immunolabeling allowed for quick and easy identification of mitotic figures (MF). It had the highest concordance with MIB1-LI. At cut-off values of 2 and 17, there was good overall sensitivity and specificity. The interobserver agreement was excellent.

Pancreatic Neuroendocrine Microtumors (WHO 2022) Are Not Always Low-Grade Neoplasms: A Case with a Highly Increased Proliferation Rate

Traditionally considered non-functional low proliferative benign neuroendocrine proliferations measuring less than 5 mm, pancreatic (neuro)endocrine microadenomas are now classified as pancreatic neuroendocrine microtumors in the 2022 WHO classification of endocrine and neuroendocrine tumors. This case report discussed the features of an incidentally identified 4.7-mm glucagon-expressing pancreatic neuroendocrine microtumor with MEN1 mutation only, chromosomally stable and an epigenetic alpha-like phenotype. The tumor was associated with an unexplained increased proliferation rate in Ki-67 of 15%. There was no associated DAXX/ATRX deficiency. The presented case challenges the conventional thought of a low proliferative disease of the so-called "pancreatic neuroendocrine microadenomas" and provides additional support to the 2022 WHO classification that also requires grading of these neoplasms. Despite exhibiting molecular features of less aggressive behavior, the case also underscores the biological complexity of pancreatic neuroendocrine microtumors. By recognizing the heterogenous spectrum of neuroendocrine neoplasms, the current case also contributes to ongoing discussions on how to optimize the clinical management of such tumors.

Improving fine needle aspiration to predict the tumor biological aggressiveness in pancreatic neuroendocrine tumors using Ki-67 proliferation index, phosphorylated histone H3 (PHH3), and BCL-2

INTRODUCTION

Surgery is the only known cure for sporadic pancreatic neuroendocrine tumors (PNETs). Therefore, the prediction of the PNETs biological aggressiveness evaluated on endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has a significant impact on clinical management. The proliferation rate of Ki-67 in PNETs can help to predict the biological aggressiveness of the tumor. In addition, there is a relatively new proliferation marker called phosphorylated histone H3 (PHH3) that can identify and quantify dividing cells in tissue samples, which is a marker highly specific to mitotic figures. Other markers such as BCL-2 also contribute to tumorigenesis and may be involved in the differentiation of neuroendocrine cells.

MATERIALS AND METHODS

A retrospective observational study was performed on patients undergoing surveillance for PNETs from January 2010 to May 2021. Data collection included the patients' age, sex, tumor location, tumor size in the surgical specimen, and tumor grade in FNA. The 2019 World Health Organization (WHO) classification guideline was followed to diagnose PNETs, including grade and stage. Immunohistochemical stainings for Ki-67, PHH3 and BCL-2 in PNETs were performed.

RESULTS

After excluding cell blocks containing fewer than 100 tumor cells, 44 patients with EUS-FNA and surgical resection specimens were included in this study. There were 19 cases of G1 PNETs, 20 cases of G2 PNETs, and 5 cases of G3 PNETs. The grade assigned based on the Ki-67 index was higher and more sensitive than that based on the mitotic count using H&E slides in some cases of G2 and G3 PNETs. However, there was no significant difference between the mitotic count using PHH3-positive tumor cells and the Ki-67 index to grade PNETs. All grade 1 tumors (19 cases) on surgical resection specimens were correctly graded on FNA (100 % concordance rate). Within the 20 G2 PNETs, 15 cases of grade 2 on surgical resection specimens were graded correctly on FNA based on the Ki-67 index only. Five cases of grade 2 PNETs on surgical resection specimens were graded as grade 1 on FNA when using only the Ki-67 index. Three of five grade 3 tumors on surgical resection specimens were graded as grade 2 on FNA based on the Ki-67 index only. Using only FNA Ki-67 to predict PNET tumor grade, the concordance (accuracy) rate was 81.8 % in total. However, all these eight cases (5 cases of G2 PNETs and 3 cases of G3 PNETs) were graded correctly by using the Ki-67 index plus mitotic rate (using PHH3 IHC stains). Four of 18 (22.2 %) patients with PNETs were positive for BCL-2 stain. In these 4 cases positive for BCL-2 stains, 3 cases were G2 PNETs and one case was G3 PNETs.

CONCLUSION

Grade and the proliferative rate in EUS-FNA can be used to predict the tumor grade in surgical resection specimens. However, when using only FNA Ki-67 to predict PNET tumor grade, about 18 % of cases were downgraded by one level. To solve the problem, immunohistochemical staining for BCL-2 and especially PHH3 would be helpful. Our results demonstrated that the mitotic count using PHH3 IHC stains not only improved the accuracy and precision of PNET grading in the surgical resection specimens, but also could reliably be used in routine scoring of mitotic figures of FNA specimens.

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.

Grading of Medullary Thyroid Carcinoma: an Interobserver Reproducibility Study

Grade, based on proliferative activity and tumor necrosis, has recently been shown to be prognostic in medullary thyroid carcinoma (MTC) in multivariate analysis. The aim of this study was to evaluate the interobserver reproducibility of assessed grade in MTC. Three groups (each group included one resident/fellow and one attending pathologist) independently evaluated a cohort of 44 sporadic MTC. For each case, all available tumor slides were reviewed, and mitotic count and the presence of tumor necrosis were recorded. Ki-67 was performed, and the Ki-67 proliferative index was determined in the area of highest proliferative activity. Tumors were graded according to the recently published International Medullary Thyroid Carcinoma Grading System (IMTCGS). Kappa statistics were calculated for each individual criterion (mitotic count, Ki-67 proliferative index, and necrosis) and for assigned IMTCGS grade. For our cohort of 44 MTCs, the kappa statistic for mitotic count, Ki-67 proliferative index, and necrosis was 0.68, 0.86, and 0.89, respectively. The kappa statistic for assigned IMTCGS grade was 0.87. Our findings indicate that there was a strong level of agreement for assessment of grade in our cohort of MTC, indicating that grade as assessed by the IMTCGS is not only prognostic but also reproducible.

Quantitative Assessment of Epithelial Proliferation in Rat Mammary Gland Using Artificial Intelligence Independent of Choice of Proliferation Marker

Epithelial proliferation in the rat mammary gland is recommended in regulatory guidelines as an endpoint for assessment of the in vivo carcinogenic potential of insulin analogues. Epithelial proliferation is traditionally assessed by immunohistochemical staining of a proliferation marker, for example, 5-bromo-2'-deoxyuridine (BrdU) or Ki67, followed by labor-intensive manual counting of positive and negative cells. The aim of this study was to develop and validate an approach for image analysis based on artificial intelligence, which can be used for quantification of proliferation in rat mammary gland, independent of the choice of proliferation marker. Furthermore, the aim was to compare the markers BrdU, Ki67, and phosphorylated histone H3 (PHH3). A sequence of image analysis applications were developed, which allowed for quantification of proliferative activity in the mammary gland epithelium. These endpoints agreed well with manually counted labeling indices, with correlation coefficients in the range ≈0.92-0.93. In addition, all three proliferation markers were significantly correlated and could detect the variation in epithelial proliferation during the estrous cycle. In conclusion, image analysis can be used to quantify epithelial proliferation in the rat mammary gland and thereby replace time-consuming manual counting. Furthermore, BrdU, Ki67, and PHH3 can be used interchangeably to assess proliferation.

Reconsideration of Clinicopathologic Prognostic Factors in Pancreatic Neuroendocrine Tumors for Better Determination of Adverse Prognosis

The question of how successful we are in predicting pancreatic neuroendocrine tumors (panNET) with poor prognosis has not been fully answered yet. The aim of this study was to investigate the effects of clinicopathological features on prognosis and to determine their validity in prediction of prognosis and whether a better prognostic classification can be made. Fifty-six patients who underwent pancreatic resection for pancreatic neuroendocrine tumor were included. The associations between clinicopathological parameters and prognosis were evaluated statistically. Efficiencies of different thresholds for tumor size, mitotic count, and Ki67 proliferation index for prognosis prediction were compared. Vascular invasion was statistically associated with high tumor grade, advanced pT stage, and mortality rate. The presence of non-functional tumor, lymphatic invasion, and > 10 cm tumor size were significantly related to shorter overall survival. Advanced pT stage (pT3-4), > 5 cm tumor size, and high tumor grade (grades 2-3) were significantly associated with shorter disease-free survival. The mortality rate showed the strongest statistical significance with mitotic count when grouped as 1: < 2, 2: 2-10, and 3: > 10 mitosis/ 2 mm². The 10% threshold value for Ki67 index was more successful in predicting adverse prognosis. Among the morphologic variants, the ductulo-insular variant was the most promising to have positive prognostic value in our series, although no statistical significance was detected. In conclusion, threshold values of 5 cm and 10 cm for tumor size, 10% for Ki67 proliferation index, and 10/2 mm² for mitotic count and vascular and lymphatic invasion assessed separately are potential prognostic candidates for better stratification of panNETs.

Digital Image Analysis of the Proliferation Markers Ki67 and Phosphohistone H3 in Gastroenteropancreatic Neuroendocrine Neoplasms: Accuracy of Grading Compared With Routine Manual Hot Spot Evaluation of the Ki67 Index

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are rare epithelial neoplasms. Grading is based on mitotic activity or the percentage of Ki67-positive cells in a hot spot. Routine methods have poor intraobserver and interobserver consistency, and objective measurements are lacking. This study aimed to evaluate digital image analysis (DIA) as an objective assessment of proliferation markers in GEP-NENs. A consecutive cohort of patients with automated DIA measurement of Ki67 (DIA Ki67) and phosphohistone H3 (DIA PHH3) on immunohistochemical slides was analyzed using Visiopharm image analysis software (Hoersholm, Denmark). The results were compared with the Ki67 index from routine pathology reports (pathology Ki67). The study included 159 patients (57% males). The median pathology Ki67 was 2.0% and DIA Ki67 was 4.1%. The interclass correlation coefficient of the DIA Ki67 compared with the pathology Ki67 showed an excellent agreement of 0.96 [95% confidence interval (CI): 0.94-0.96]. The observed kappa value was 0.86 (95% CI: 0.81-0.91) when comparing grades based on the same methods. PHH3 was measured in 145 (91.2%) cases. The observed kappa value was 0.74. (95% CI: 0.65-0.83) when comparing grade based on the DIA PHH3 and the pathology Ki67. The DIA Ki67 shows excellent agreement with the pathology Ki67. The DIA PHH3 measurements were more varied and cannot replace other methods for grading GEP-NENs.

Phospho-histone-H3 immunostaining for pulmonary carcinoids: impact on clinical appraisal, interobserver correlation, and diagnostic processing efficiency

Lung carcinoid tumors are classified as either typical or atypical based on the presence of necrosis and the maximum mitotic count per 2 mm² area. Determining the mitotic count, which is manually conducted on slides stained with hematoxylin and eosin (HE), is time-consuming and subject to high interobserver variability. The objective of this study was to test the sensitivity and specificity of a surrogate mitosis marker, phospho-histone-H3 (PHH3) immunostaining, in the processing of pulmonary carcinoids as compared with the standard HE evaluation. Carcinoid tissue blocks that were available from lung resection specimens were analyzed using HE and PHH3 stains. Two thoracic pathologists and two residents determined the mitotic count on HE and PHH3 stains in accordance with the 2015 WHO guidelines and recorded the time required to complete this task. For both methods, the interobserver agreement among raters for the mitotic count/2 mm² was assessed by conducting intraclass correlation analyses. We found that for both pathologists and residents, the time required to determine the mitotic count using the PHH3 method was reduced compared with the traditional HE method. Furthermore, residents detected more mitoses/2 mm² using the PHH3 stain compared with the HE method. More importantly, the PHH3 method yielded better interobserver agreement than the HE method in terms of mitoses/mm² detection. Overall, our data confirmed that histologic assessments of carcinoid tumors using PHH3 staining provides practical benefits in terms of scoring times, mitosis detection, and reproducibility of mitotic counts. In addition, we found that the benefit was even greater for less experienced pathologists.

CUX1-Transcriptional Master Regulator of Tumor Progression in Pancreatic Neuroendocrine Tumors

Recently, we identified the homeodomain transcription factor Cut homeobox 1 (CUX1) as mediator of tumour de-differentiation and metastatic behaviour in human insulinoma patients. In insulinomas, CUX1 enhanced tumour progression by stimulating proliferation and angiogenesis in vitro and in vivo. In patients with non-functional pancreatic neuroendocrine tumours (PanNET), however, the impact of CUX1 remains to be elucidated. Here, we analysed CUX1 expression in two large independent cohorts (n = 43 and n = 141 tissues) of non-functional treatment-naïve and pre-treated PanNET patients, as well as in the RIP1Tag2 mouse model of pancreatic neuroendocrine tumours. To further assess the functional role of CUX1, expression profiling of DNA damage-, proliferation- and apoptosis-associated genes was performed in CUX1-overexpressing Bon-1 cells. Validation of differentially regulated genes was performed in Bon-1 and QGP1 cells with knock-down and overexpression strategies. CUX1 expression assessed by a predefined immunoreactivity score (IRS) was significantly associated with shorter progression-free survival (PFS) of pre-treated PanNET patients (23 vs. 8 months; p = 0.005). In treatment-naïve patients, CUX1 was negatively correlated with grading and recurrence-free survival (mRFS of 39 versus 8 months; p = 0.022). In both groups, high CUX1 levels indicated a metastatic phenotype. Functionally, CUX1 upregulated expression of caspases and death associated protein kinase 1 (DAPK1), known as mediators of tumour progression and resistance to cytotoxic drugs. This was also confirmed in both cell lines and human tissues. In the RIP1Tag2 mouse model, CUX1 expression was associated with advanced tumour stage and resistance to apoptosis. In summary, we identified the transcription factor CUX1 as mediator of tumour progression in non-functional PanNET in vitro and in vivo, indicating that the CUX1-dependent signalling network is a promising target for future therapeutic intervention.

Pancreatic neuroendocrine neoplasms: current state and ongoing controversies on terminology, classification and prognostication

Significant improvements have taken place in our understanding of classification neuroendocrine neoplasms of the pancreas in the past decade. These are now regarded in three entirely separate categories: (I) neuroendocrine tumors (PanNETs) are by definition well differentiated, the pancreatic counterpart of carcinoids; (II) neuroendocrine carcinomas, which are poorly differentiated (PDNEC), the pancreatic examples of small cell carcinomas or large cell neuroendocrine carcinomas; (III) other neoplasms that have neuroendocrine differentiation or a distinct neuroendocrine component. PanNETs are by far the most common. They are now regarded as malignancies (albeit often curable when low grade and low stage) with the exception of minute incidental proliferations (tumorlets, or dysplastic-like changes) seen in the setting of some syndromes like MEN. PanNETs are staged based on their size, and for small T1 tumors, watchful waiting is now being considered, although these tumors are also known to show about 10% metastatic rate and/or progression, creating concerns about this approach. PanNETs are graded into 3, based on the proliferative activity, mostly based on the Ki-67 index, and also partly mitotic activity, although the latter seldom if ever is the determinant of the final grade. Neuroendocrine neoplasms with well differentiated morphology but Ki-67 >20% are now regarded as PanNET Grade 3 (G3); they have been shown to have a prognosis significantly worse than lesser grade PanNETs but still incomparably better than frank PDNECs, the latter typically has Ki-67 >50% (often much higher) and require platinum-based chemotherapy. There are also cases that are ambiguous between PanNET-G3 and PDNEC, and very rarely transformation of the former to the latter appears to occur. For low grade (G1/G2) PanNETs, more refined criteria to further prognosticate this group are needed. Morphologic variants being recognized may bring new perspectives to this group.

Diagnostic and Prognostic Biomarkers of Adrenal Cortical Carcinoma

The diagnosis of low-grade adrenal cortical carcinoma (ACC) confined to the adrenal gland can be challenging. Although there are diagnostic and prognostic molecular tests for ACC, they remain largely unutilized. We examined the diagnostic and prognostic value of altered reticulin framework and the immunoprofile of biomarkers including IGF-2, proteins involved in cell proliferation and mitotic spindle regulation (Ki67, p53, BUB1B, HURP, NEK2), DNA damage repair (PBK, γ-H2AX), telomere regulation (DAX, ATRX), wnt-signaling pathway (beta-catenin) and PI3K signaling pathway (PTEN, phospho-mTOR) in a tissue microarray of 50 adenomas and 43 carcinomas that were characterized for angioinvasion as defined by strict criteria, Weiss score, and mitotic rate-based tumor grade. IGF-2 and proteins involved in cell proliferation and mitotic spindle regulation (Ki67, p53, BUB1B, HURP, NEK2), DNA damage proteins (PBK, γ-H2AX), regulators of telomeres (DAXX, ATRX), and beta-catenin revealed characteristic expression profiles enabling the distinction of carcinomas from adenomas. Not all biomarkers were informative in all carcinomas. IGF-2 was the most useful biomarker of malignancy irrespective of tumor grade and cytomorphologic features, as juxtanuclear Golgi-pattern IGF-2 reactivity optimized for high specificity was identified in up to 80% of carcinomas and in no adenomas. Loss rather than qualitative alterations of the reticulin framework yielded statistical difference between carcinoma and adenoma. Angioinvasion defined as tumor cells invading through a vessel wall and intravascular tumor cells admixed with thrombus proved to be the best prognostic parameter, predicting adverse outcome in the entire cohort as well as within low-grade ACCs. Low mitotic tumor grade, Weiss score, global loss of DAXX expression, and high phospho-mTOR expression correlated with disease-free survival, but Weiss score and biomarkers failed to predict adverse outcome in low-grade disease. Our results underscore the importance of careful morphologic assessment coupled with ancillary diagnostic and prognostic biomarkers of ACC.

Advances in the cytologic diagnosis of gastroenteropancreatic neuroendocrine neoplasms

Two-thirds of neuroendocrine neoplasms arising in the human body originate from the gastrointestinal system or pancreas. Gastroenteropancreatic neuroendocrine neoplasms are heterogeneous, comprising both well differentiated neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinomas (NECs). The clinical presentation, molecular characteristics, and behavior are distinct for NETs and NECs. Fine-needle aspiration is an important modality for the primary diagnosis and staging of these neoplasms and can provide information of prognostic and therapeutic significance. Our evolving understanding of neuroendocrine neoplasm biology has led to several iterations of classification. In this review, new concepts and issues most relevant to cytology diagnosis of gastroenteropancreatic neuroendocrine neoplasms are discussed, such as newer detection methods that aid in diagnosis and staging, recent changes in World Health Organization classification, practical issues related to grading these neoplasms on cytology, guidelines for diagnostic reporting, and panels of immunohistochemical stains for the diagnosis of metastasis. The current understanding of genetic and epigenetic events related to tumor development and potential applications for cytology also are presented as they relate to prognostication and recent therapeutic advances.

Immunohistochemical Biomarkers of Gastrointestinal, Pancreatic, Pulmonary, and Thymic Neuroendocrine Neoplasms

Neuroendocrine neoplasms (NENs) are a heterogeneous group of epithelial neoplastic proliferations that irrespective of their primary site share features of neural and endocrine differentiation including the presence of secretory granules, synaptic-like vesicles, and the ability to produce amine and/or peptide hormones. NENs encompass a wide spectrum of neoplasms ranging from well-differentiated indolent tumors to highly aggressive poorly differentiated neuroendocrine carcinomas. Most cases arise in the digestive system and in thoracic organs, i.e., the lung and thymus. A correct diagnostic approach is crucial for the management of patients with both digestive and thoracic NENs, because their high clinical and biological heterogeneity is related to their prognosis and response to therapy. In this context, immunohistochemistry represents an indispensable diagnostic tool that pathologists need to use for the correct diagnosis and classification of such neoplasms. In addition, immunohistochemistry is also useful in identifying prognostic and theranostic markers. In the present article, the authors will review the role of immunohistochemistry in the routine workup of digestive and thoracic NENs.

Prognostic factors in head and neck mucosal malignant melanoma

OBJECTIVE

Primary mucosal malignant melanoma of the head and neck (HN-PMMM) is an aggressive and uncommon neoplasm. Herein, we present a series of 33 patients and the results of treatment, and aimed to determine prognostic factors in HN-PMMM.

METHODS

Patients who were diagnosed as having HN-PMMM in our reference hospital, between 2005 and 2014 were evaluated. Thirty-three of these patients who had follow-up data were included. Surgical margin status was extracted from the original pathology reports. Archived materials were retrieved for the histopathologic findings: ulceration, necrosis, lymphovascular invasion, perineural invasion, pigmentation, and presence of an in situ component. Mitotic activity was evaluated using phosphohistone H3 (PHH3) immunohistochemical staining.

RESULTS

We found an association of PHH3 mitotic activity with overall survival in a univariate analysis and to our knowledge, this is the first report among the available case series of HN-PMMM to evaluate mitotic activity using immunohistochemical staining. We also investigated the relationship between multicentricity and locoregional recurrence, which the authors believe is also a first.

CONCLUSION

PHH3 mitotic activity can be used a prognostic factor for head and neck mucosal malignant melanoma.

Tumor Digital Masking Allows Precise Patient Triaging: A Study Based on Ki-67 Scoring in Gastrointestinal Stromal Tumors

BACKGROUND

Technological advances constantly provide cutting-edge tools that enhance the progress of diagnostic capabilities. Gastrointestinal stromal tumors belong to a family of mesenchymal tumors where patient triaging is still based on traditional criteria such as mitotic count, tumor size, and tumor location. Limitations of the human eye and randomness in choice of area for mitotic figure counting compel us to seek more objective solutions such as digital image analysis. Presently, the labelling of proliferative activity is becoming a routine task amidst many cancers. The purpose of the present study was to compare the traditional method of prediction based on mitotic ratio with digital image analysis of cell cycle-dependent proteins.

METHODS

Fifty-seven eligible cases were enrolled. Furthermore, a digital analysis of previously performed whole tissue section immunohistochemical assays was executed. Digital labelling covered both hotspots and not-hotspots equally.

RESULTS

We noted a significant diversity of proliferative activities, and consequently, the results pointed to 6.5% of Ki-67, counted in hotspots, as the optimal cut-off for low-high-grade GIST. ROC analysis (AUC = 0.913; 95% CI: 0.828-0.997, p < 0.00001) and odds ratio (OR = 40.0, 95% CI: 6.7-237.3, p < 0.0001) pointed to Ki-67 16% as the cut-off for very high-grade (groups 5-6) cases. With help of a tumor digital map, we revealed possible errors resulting from a wrong choice of field for analysis. We confirmed that Ki-67 scores are in line with the level of intracellular metabolism that could be used as the additional biomarker.

CONCLUSIONS

Tumor digital masking is very promising solution for repeatable and objective labelling. Software adjustments of nuclear shape, outlines, size, etc. are helpful to omit other Ki-67-positive cells especially small lymphocytes. Our results pointed to Ki-67 as a good biomarker in GIST, but concurrently, we noted significant differences in used digital approaches which could lead to unequivocal results.

[Classification of pancreatic neuroendocrine tumours: Changes made in the 2017 WHO classification of tumours of endocrine organs and perspectives for the future]

The WHO classification of the tumors of endocrine organs, published in July 2017, has introduced significant changes in the classification of pancreatic neuroendocrine tumors, the previous version of which has appeared in 2010, within the WHO classification of the tumors of the digestive system. The main change is the introduction of a new category of well-differentiated neoplasms, neuroendocrine tumors G3, in addition to the previous categories of neuroendocrine tumors G1 and G2. The differential diagnosis between neuroendocrine tumors G3 (well-differentiated) and neuroendocrine carcinomas (poorly-differentiated) might be difficult; the authors of the WHO classification therefore suggest the use of a number of immunohistochemical markers to facilitate the distinction between the two entities. The other changes are: (a) the modification of the threshold between neuroendocrine tumors G1 and G2, now set at 3%; (b) the terminology used for mixed tumors: the previous term mixed adeno-neuroendocrine carcinoma (MANEC) is substituted by the term mixed neuroendocrine-non neuroendocrine neoplasm (MiNEN). Finally, the recommendations for Ki-67 index evaluation are actualized. Even if these changes only concern, stricto sensu, the neuroendocrine tumors of pancreatic location, they will probably be applied, de facto, for all digestive neuroendocrine tumors. The revision of the histological classification of pancreatic neuroendocrine tumors coincides with the revision of their UICC TNM staging; significant changes have been made in the criteria for T3 and T4 stages. Our professional practices have to take into account all these modifications.

The mitosis-specific marker phosphohistone-H3 (PHH3) is an independent prognosticator in uterine smooth muscle tumours: an outcome-based study

AIMS

Accurate mitosis counting, which is important in the diagnosis of uterine smooth muscle tumours (USMTs), is often difficult and subjective. The mitosis-specific immunohistochemical marker phosphohistone-H3 (PHH3) has been shown to be diagnostically useful, but its expression, in relation to outcome, has not been thoroughly investigated. The aim of this study is to evaluate PHH3 as a diagnostic and prognostic marker in USMTs.

METHODS AND RESULTS

PHH3 expression was evaluated in 55 leiomyosarcomas (LMSs), 26 smooth muscle tumours of uncertain malignant potential (STUMPs), 18 leiomyomas with bizarre nuclei (LBN), and 12 leiomyomas (LMs). Scores were expressed as counts per 10 high-power fields (HPFs). Median follow-up durations of patients with LMS, STUMP, LBN and LM were, respectively, 39, 78, 65.5 and 49.5 months. Twenty-eight patients with LMSs (50.9%) died, and two (7.7%) patients with STUMPs experienced recurrence. The median PHH3 scores for LMSs were significantly higher than those for other categories of tumour. A score of ≥29/10 HPFs was also independently associated with a poor outcome. To test whether the PHH3 score could distinguish between benign USMTs with atypical histology and those that were clinically malignant, two biological groups were further delineated. Patients in group 1 (18 LBNs and 24 STUMPs) all had an uneventful outcome, whereas patients in group 2 (two recurrent STUMPs and 32 LMSs) all had a recurrence or tumour-related death. Median PHH3 scores for the two groups were, respectively, 2/10 HPFs and 27/10 HPFs. A PHH3 score of ≥7/10 HPFs was highly associated with malignancy.

CONCLUSION

PHH3 is useful in evaluation of the biological behaviour of USMTs, and may serve as a prognostic indicator for LMSs.