Development of Automated Risk Stratification for Sporadic Odontogenic Keratocyst Whole Slide Images with an Attention-Based Image Sequence Analyzer.

(1) Background: The categorization of recurrent and non-recurrent odontogenic keratocyst is complex and challenging for both clinicians and pathologists. What sets this cyst apart is its aggressive nature and high likelihood of recurrence. Despite identifying various predictive clinical/radiological/histopathological parameters, clinicians still face difficulties in therapeutic management due to its inherent aggressive nature. This research aims to build a pipeline system that accurately detects recurring and non-recurring OKC. (2) Objective: To automate the risk stratification of OKCs as recurring or non-recurring based on whole slide images (WSIs) using an attention-based image sequence analyzer (ABISA). (3) Materials and methods: The presented architecture combines transformer-based self-attention mechanisms with sequential modeling using LSTM (long short-term memory) to predict the class label. This architecture leverages self-attention to capture spatial dependencies in image patches and LSTM to capture sequential dependencies across patches or frames, making it suitable for this image analysis. These two powerful combinations were integrated and applied on a custom dataset of 48 labeled WSIs (508 tiled images) generated from the highest zoom level WSI. (4) Results: The proposed ABISA algorithm attained 0.98, 1.0, and 0.98 testing accuracy, recall, and area under the curve, respectively, whereas VGG16, VGG19, and Inception V3, standard vision transformer attained testing accuracies of 0.80, 0.73, 0.82, 0.91, respectively. ABISA used 58% fewer trainable parameters than the standard vision transformer. (5) Conclusions: The proposed novel ABISA algorithm was integrated into a risk stratification pipeline to automate the detection of recurring OKC significantly faster, thus allowing the pathologist to define risk stratification faster.

Exosomes: Mediators of cellular communication in potentially malignant oral lesions and head and neck cancers.

Exosomes are a unique type of extracellular vesicles that contain a plethora of biological cargo such as miRNA, mRNA, long non-coding RNA, DNA, proteins and lipids. Exosomes serve as very effective means of intercellular communication. Due the presence of a lipid bilayer membrane, exosomes are resistant to degradation and are highly stable. This makes them easily identifiable in blood and other bodily fluids such as saliva. The exosomes that are secreted from a parent cell directly release their contents into the cytoplasm of a recipient cell and influence their cellular activity and function. Exosomes can also transfer their content between cancer cells and normal cells and regulate the tumor microenvironment. Exosomes play a vital role in tumor growth, tumor invasion and metastasis. Exosomes provide a multitude of molecular and genetic information and have become valuable indicators of disease activity at the cellular level. This review explores the molecular characteristics of exosomes and the role that exosomes play in the tumorigenesis pathway of potentially malignant oral lesions and head and neck cancers The application of exosomes in the treatment of oral cancers is also envisioned. Exosomes are very small and can easily pass through various biological barriers, making them very good delivery vectors for therapeutic drugs as well as to selectively induce DNA's mRNA and miRNAs into targeted cancer cells.

Building Automation Pipeline for Diagnostic Classification of Sporadic Odontogenic Keratocysts and Non-Keratocysts Using Whole-Slide Images.

The microscopic diagnostic differentiation of odontogenic cysts from other cysts is intricate and may cause perplexity for both clinicians and pathologists. Of particular interest is the odontogenic keratocyst (OKC), a developmental cyst with unique histopathological and clinical characteristics. Nevertheless, what distinguishes this cyst is its aggressive nature and high tendency for recurrence. Clinicians encounter challenges in dealing with this frequently encountered jaw lesion, as there is no consensus on surgical treatment. Therefore, the accurate and early diagnosis of such cysts will benefit clinicians in terms of treatment management and spare subjects from the mental agony of suffering from aggressive OKCs, which impact their quality of life. The objective of this research is to develop an automated OKC diagnostic system that can function as a decision support tool for pathologists, whether they are working locally or remotely. This system will provide them with additional data and insights to enhance their decision-making abilities. This research aims to provide an automation pipeline to classify whole-slide images of OKCs and non-keratocysts (non-KCs: dentigerous and radicular cysts). OKC diagnosis and prognosis using the histopathological analysis of tissues using whole-slide images (WSIs) with a deep-learning approach is an emerging research area. WSIs have the unique advantage of magnifying tissues with high resolution without losing information. The contribution of this research is a novel, deep-learning-based, and efficient algorithm that reduces the trainable parameters and, in turn, the memory footprint. This is achieved using principal component analysis (PCA) and the ReliefF feature selection algorithm (ReliefF) in a convolutional neural network (CNN) named P-C-ReliefF. The proposed model reduces the trainable parameters compared to standard CNN, achieving 97% classification accuracy.

Oral Squamous Cell Carcinoma Frequency in Young Patients from Referral Centers Around the World.

Oral squamous cell carcinoma (OSCC) commonly affects older patients; however, several studies have documented an increase in its incidence among younger patients. Therefore, it is important to investigate if this trend is also found in different geographic regions. The pathology files of diagnostic and therapeutic institutions from different parts of the globe were searched for OSCC cases diagnosed from 1998 to 2018. Data regarding the sex, age, and tumor location of all cases, as well as the histologic grade and history of exposure to risk habits of cases diagnosed as OSCC in young patients (≤ 40 years of age) were obtained. The Chi-square test was used to determine any increasing trend. A total of 10,727 OSCC cases were identified, of which 626 cases affected young patients (5.8%). Manipal institution (India) showed the highest number of young patients (13.2%). Males were the most affected in both age groups, with the tongue and floor of the mouth being the most affected subsites. OSCC in young individuals were usually graded as well or moderately differentiated. Only 0.9% of the cases occurred in young patients without a reported risk habit. There was no increasing trend in the institutions and the period investigated (p > 0.05), but a decreasing trend was observed in Hong Kong and the sample as a whole (p < 0.001). In conclusion there was no increase of OSCC in young patients in the institutions investigated and young white females not exposed to any known risk factor represented a rare group of patients affected by OSCC.

Simvastatin in polymer bioscaffold for bone regeneration. An in vitro and in vivo analysis.

OBJECTIVE: The study aimed to fabricate and test the biocompatibility of a polylactic-co-glycolic acid (PLGA) based guided tissue regeneration membrane impregnated with 'simvastatin' to promote sustained drug delivery near osseous defects and evaluate the regenerative potential of the membrane histologically. MATERIALS AND METHODS: We tested the mechanical properties and cytotoxicity of an indigenously fabricated PLGA membrane incorporated with simvastatin (1 mg/cm2). An animal study evaluated the regenerative potential of the membrane. Twenty-four adult Wistar rats, approximately 175 g in weight, were used in this study. The rats were divided randomly into four groups based on the postoperative healing periods into ten days, 1, 3, and 6 months. Within each time group, six rats were divided into three subgroups: Subgroup A - sham surgery controls; Subgroup B - PLGA without Simvastatin; Subgroup C - PLGA with simvastatin tests. The radiographic examination intervals were ten days, 1 and 3 months, while the histological assessment was around 1, 3, and 6 months. RESULTS: Simvastatin content was distributed uniformly in all the prepared membranes and was equivalent to 1 mg/cm2. 100 mg PLGA membrane with simvastatin demonstrated uniform drug release over time, excellent mechanical properties, and biocompatibility. The rat models in Subgroup C had better bone tissue formation radiographically and histologically. CONCLUSION: The study suggested that 'PLGA with Simvastatin' has the requisite properties to serve as a third-generation barrier membrane with the potential for local drug delivery.

Elucidating the role of excision repair cross-complement group 1 in oral epithelial dysplasia and early invasive squamous cell carcinoma: An immunohistochemical study.

OBJECTIVES: Oral epithelial dysplasia (OED) is characterized by cellular alterations which have the proclivity of progressing to squamous cell carcinoma. Excision repair cross-complement group 1 (ERCC1) is one of the key proteins involved in nucleotide excision repair (NER) pathway. The expression of ERCC1 has been studied in colorectal, esophageal, ovarian and oral squamous cell carcinoma; but, very few studies have been done to apprehend the expression of ERCC1 in OED and early invasive squamous cell carcinoma (EISCC). The goal of this study is to evaluate the role of ERCC1 in OED and EISCC. MATERIALS AND METHODS: Histopathologically diagnosed cases of moderate dysplasia (n = 10), severe dysplasia (n = 10) and EISCC (n = 10) were retrieved. 4 µ thick sections were cut from the formalin-fixed paraffin-embedded tissue blocks. The sections were immunohistochemically stained for ERCC1 following standard protocols. The expression of ERCC1 was evaluated semiquantitatively. Statistical analysis was carried out using Fischer's exact t-test. RESULTS: The expression of ERCC1 was found to be strong (+3) in EISCC, moderate (+2) in severe dysplasia and mild (+1) in moderate dysplasia. Thus, the results were statistically significant between the three groups (P < 0.001). CONCLUSION: Disruption in the mechanisms that regulate cell cycle checkpoints and DNA repair mechanism results in genomic instability; these alterations might contribute to carcinoma. ERCC1 is essential to repair the DNA damage induced by various carcinogens. The present study shows significant difference in the expression of ERCC1 between EISCC and OED, which suggests ERCC1 could be used as one of the predictive markers.

Spalt-like transcription factor 4 expression in oral epithelial dysplasia and oral squamous cell carcinoma: An immunohistochemical appraisal.

BACKGROUND: Spalt-like transcription factor 4 (SALL4) is a stem cell marker that plays a critical role in maintaining the pluripotency and self-renewal of embryonic and hematopoietic stem cells. Only a few studies have been done to apprehend the expression of SALL4 in the potentially malignant oral lesion (leukoplakia with dysplasia) and oral squamous cell carcinoma (OSCC). AIM: The aim of this study is to evaluate the expression of SALL4 in leukoplakia with dysplasia and OSCC and to correlate the expression of the marker (SALL4) with the various clinicopathological parameters and patient outcome. MATERIALS AND METHODS: Immunohistochemistry for SALL4 protein was performed on 140 cases: those histopathologically confirmed cases of leukoplakia with dysplasia (n = 30) and OSCC (n = 110). Ten cases of nonepithelial neoplasm (fibroepithelial hyperplasia and excised tissue surrounding impacted third molars) were taken as control. Statistical analyses were applied to evaluate correlations between SALL4 overexpression and clinicopathological features of leukoplakia and OSCC. Survival rates were analyzed using Kaplan-Meier method. RESULTS: SALL4 positivity was observed to be higher (P = 0.001) in the tumor cells of OSCC with Immuno Reactive Score (IRS) ranging from 0 to 9. Poorly differentiated squamous cell carcinoma (SCC) had paramount higher expression with a median IRS of 6. Similar IRS and above (IRS, 6-9) was observed in Stage I (five cases), which recurred and well-differentiated cases with metastasis (four cases) while in leukoplakia with dysplasia the SALL4 expression was weak with a range of 2-4. CONCLUSIONS: SALL4 being one of the cancer stem cell molecules plays an important role in the progression of oral cancer, which was evident in this study. This could also account for aggressive clinical behavior. Follow-up of these patients would relate this molecule could be responsible for cancer relapse. Patients diagnosed to have oral epithelial dysplasia had a low expression of SALL4, are under follow-up, although seven cases did transform to SCC. Thus, we conclude, SALL4 may be of prognostic relevance, but in oral epithelial dysplasia, it requires further investigations.

Paediatric unicystic ameloblastoma - A report of 2 cases.

Unicytic ameloblastoma is a variant of ameloblastoma encompassing about 6% of ameloblastomas. They represent cystic lesions that reveal clinical and radiographic features of a cyst, but the histopathological features demonstrate a typical ameloblastomatous epithelium lining the cyst. Plexiform unicystic ameloblastoma, a variant of unicystic ameloblastoma refers to the pattern of proliferation where one or more nodules of ameloblastomatous epithelium project from the cystic lining into the lumen demonstrating an edematous plexiform pattern. The lesion is seen more commonly in the third and fourth decades of life with less than 10% of cases being reported in the first decade. Here, we report two cases of unicystic ameloblastoma in paediatric patients. This report also aims to provide an insight on the pathogenesis and treatment aspects of this distinct entity.

Odontogenic cysts and odontogenic tumors in a large rural area from India. A 10-year reflection.

OBJECTIVES: To determine the prevalence of odontogenic cysts and tumors along with age range, sex distribution, site of presentation and also to identify the most common type of odontogenic cyst and tumor among the population of coastal Karnataka over a 10-year period. METHODS: Data was collected from patient records and histologically diagnosed cases of odontogenic cysts and tumors. The age, gender of patients, as well as the site of lesion was recorded. RESULTS: A total of 167 cases were retrieved. Among them, 125 cases were diagnosed as odontogenic cysts and 42 cases were odontogenic tumors. Radicular cyst was the most frequently diagnosed cyst and unicystic ameloblastoma was the most frequently diagnosed tumor. A strong predilection for males was observed for both the odontogenic cysts and odontogenic tumors. Odontogenic cysts were more commonly seen in individuals in the age range 21-41 years, while odontogenic tumors were frequently seen in individuals in the age range 1-20 years. CONCLUSION: This study provides an epidemiological profile of odontogenic cysts and odontogenic tumors among a rural population of coastal Karnataka. There is a notable variation in demographic profile of odontogenic cysts and odontogenic tumors in this population when compared with other populations.

Evaluation of SOX2 and podoplanin expression in oral epithelial dysplasia and its correlation with malignant transformation.

AIM: Oral carcinogenesis cascade is a complex process, characterized by variable numbers of genetic and epigenetic alterations of various genes with manifold roles that could serve as biological hallmarks. This study was undertaken to assess the protein expression of SOX2 and podoplanin in oral epithelial dysplasia and correlate the expression with clinicopathological parameters and risk of malignant transformation. METHODS: SOX2 and podoplanin expression were analyzed in 60 cases of oral epithelial dysplasia. The association between SOX2 and podoplanin expression with various clinicopathological parameters and transformation to oral cancer was analyzed. RESULTS: A higher Histoscore was seen in 55% of moderate and 30% of severe dysplasia. 25% of the cases showed a negative podoplanin expression and 30% of patients had higher podoplanin expression (score 2 and 3). Though there was significant association of both SOX2 and podoplanin expression with the degree of dysplasia, the association of their expression with transformation to oral squamous cell carcinoma did not reach statistical significance. CONCLUSION: Alteration in SOX2 and podoplanin is likely an important event in head and neck carcinogenesis; however, their expression may be valuable only in a few cases of oral epithelial dysplasia to assess the risk of malignant transformation.

A curious case of central odontogenic fibroma: A novel perspective.

We appraise a case of central odontogenic fibroma (COF) with unusual histologic features of entrapped neural elements and mast cells. The presence of mast cells attributed to the release of stem cell factor, the principal growth and activating factor of mast cells. A putative role for C-kit and mast cells in the pathogenesis of COF is described.

Giant-cell fibroma: Understanding the nature of the melanin-laden cells.

Giant-cell fibroma is a localized, benign fibrous mucosal mass, which clinically mimics any other fibroepithelial growth, and its distinction from other lesions is on the basis of its peculiar histopathology. A case of giant-cell fibroma with stroma strewn with brown pigment-laden cells is presented herewith. Immunohistochemical staining aided with histochemical reaction to understand the origin of these cells was carried out. Various mechanisms that explain the presence of melanin granules in reactive lesions of giant-cell fibroma is discussed in the present report.

The prognostic implication of the expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in primary locally advanced oral squamous cell carcinoma cases: a tissue microarray study.

Oral squamous cell carcinomas comprise a heterogeneous tumor cell population with varied molecular characteristics, which makes prognostication of these tumors a complex and challenging issue. Thus, molecular profiling of these tumors is advantageous for an accurate prognostication and treatment planning. This is a retrospective study on a cohort of primary locally advanced oral squamous cell carcinomas (n = 178) of an Indian rural population. The expression of EGFR, p53, cyclin D1, Bcl-2 and p16 in a cohort of primary locally advanced oral squamous cell carcinomas was evaluated. A potential biomarker that can predict the tumor response to treatment was identified. Formalin-fixed paraffin-embedded tumor blocks of (n = 178) of histopathologically diagnosed cases of locally advanced oral squamous cell carcinomas were selected. Tissue microarray blocks were constructed with 2 cores of 2 mm diameter from each tumor block. Four-micron-thick sections were cut from these tissue microarray blocks. These tissue microarray sections were immunohistochemically stained for EGFR, p53, Bcl-2, cyclin D1 and p16. In this cohort, EGFR was the most frequently expressed 150/178 (84%) biomarker of the cases. Kaplan-Meier analysis showed a significant association (p = 0.038) between expression of p53 and a poor prognosis. A Poisson regression analysis showed that tumors that expressed p53 had a two times greater chance of recurrence (unadjusted IRR-95% CI 2.08 (1.03, 4.5), adjusted IRR-2.29 (1.08, 4.8) compared with the tumors that did not express this biomarker. Molecular profiling of oral squamous cell carcinomas will enable us to categorize our patients into more realistic risk groups. With biologically guided tumor characterization, personalized treatment protocols can be designed for individual patients, which will improve the quality of life of these patients.

Translational approach utilizing COX-2, p53, and MDM2 expressions in malignant transformation of oral submucous fibrosis.

About 20% of the world's population uses some form of betel nut, which suggests that the incidence of oral submucous fibrosis (OSF) is higher than current estimates. OSF has the potential to undergo malignant transformation; thus, there is a need to identify relevant markers to assess its aggressiveness. We evaluated changes in COX-2, p53, and MDM2 expressions in progressive OSF. Expressions of COX-2, p53, and MDM2 increased with OSF progression. There was a strong association between COX-2 overexpression and recurrence of oral squamous cell carcinoma (P < 0.001) and a positive relation between increased MDM2 expression and failure of radiotherapy (P = 0.007). These findings suggest that COX-2 is an important marker of disease progression and that MDM2 expression is useful for treatment planning.

Critical biomarkers of epithelial-mesenchymal transition in the head and neck cancers.

Epithelial-mesenchymal transition (EMT), a key developmental program has been shown to occur in wound healing, organ fibrosis and in the initiation of metastasis for cancer progression. EMT is a process that describes the development of motile, mesenchymal-like cells from non-motile parent epithelial cells. Plasticity of the cells enable significant changes in cell phenotypes and this process is governed by the interplay among different functional classes of regulatory molecules. The process typically involves the control of specific gene expression programs with distinct functional impacts on the behavior of cells. An important feature of cellular plasticity, EMT has in the recent times attracted broad interest in the field of cancer research, tumor invasion and metastases. A complete understanding of the molecular events of EMT and a search for novel molecular regulators is required for prospective targets for therapeutic interventions. This review summarizes the critical biomarkers of EMT in the head and neck cancers.

Role of immunomarkers in the clinicopathological analysis of unicystic ameloblastoma.

PURPOSE: The clinical behavior of unicystic ameloblastoma varies according to its subtype. The assessment of its proliferative capacity, neovascularization, and invasiveness using relevant immunomarkers may aid in appropriate surgical therapeutic protocol. METHODS: 18 cases of clinically and histologically confirmed unicystic ameloblastoma, categorized as luminal, intraluminal, or mural subtypes, were analyzed retrospectively. Immunomarkers such as Ki-67, CD34, MMP-2, and MMP-9 were studied to evaluate their behavior. RESULTS: Labeling index of Ki-67 was 4.25% in the intraluminal subtype, compared with 2.14% in the luminal and 4.04% in the mural variant (P = 0.3). CD34 immunostaining was significantly higher in the mural variant (43 per high power field) than the other two subtypes (P = 0.04). MMP-2 and MMP-9 were strongly expressed in mural, moderately in intraluminal, and weakly to absent in luminal variant. CONCLUSIONS: High proliferative index, angiogenesis, and protease activity in the mural ameloblastoma, ascertained by the expression of these markers, confirm its aggressive phenotype. The intraluminal and luminal subtype exhibiting decreased expression are compatible with their indolent clinical behavior.

ß-Catenin expression in benign and malignant salivary gland tumors.

OBJECTIVE: To assess the expression of ß-catenin in benign and malignant salivary gland tumors and to investigate the possible role of ß-catenin in the behavior of salivary gland tumors. STUDY DESIGN: Paraffin embedded tissues from 45 salivary gland tumors were studied immunohistochemically for expression of ß-catenin. RESULT: Reduced/aberrant ß-catenin expression was seen in benign and malignant salivary gland tumors. Cytoplasmic localization and reduced membranous expression were comparatively observed more in malignant salivary gland tumors. Additionally, in pleomorphic adenomas (PAs), ß-catenin exhibited intense staining in cells arranged in the form of ducts/tubules, whereas cells in clusters and sheets showed weaker immunoreactivity. CONCLUSION: Reduced and cytoplasmic localization of ß-catenin could indicate lack of differentiation, invasive potential, and aggressive behavior in malignant salivary gland tumors. Furthermore, change in expression based on the arrangement of tumor cells may suggest that ß-catenin may have a role in morphological variations seen in PAs.