Keratosis of unknown significance and leukoplakia: a preliminary study

Oral Mucosa and Saliva Alterations Related to Vape

OBJECTIVES

Electronic nicotine delivery systems (e-cigarette, pod, and vape) are currently among the tobacco consumption of adolescents and young adults. The aim is to show oral mucosa and saliva alterations related to vape.

MATERIAL AND METHODS

A vape-user patient, presenting a white plaque in the posterior region of the hard palate, underwent clinical examination, sialometry, pH evaluation, and excisional biopsy of the white lesion. Molecular changes in saliva and vape liquid were analyzed by vibrational spectroscopy.

RESULTS

The histopathological analyses showed hyperparakeratosis without dysplasia. Formaldehyde, ketones, and aromatic hydrocarbon species were identified in e-cig liquid by the FTIR.

CONCLUSIONS

The use of vape may be related to the development of hyperkeratotic lesions in the oral mucosa as well as significantly modify the patient's salivary patterns as the vape liquid presents carcinogenic and cytotoxic components in its composition.

The value of regular follow-up of oral leukoplakia for early detection of malignant transformation

OBJECTIVES

Evaluate whether regular follow-up of oral leukoplakia (OL) resulted in early detection of malignant transformation (MT).

METHOD

Two hundred and twenty-two consecutive patients with OL (147 females, 75 males); median follow-up period of 64 months (range: 12-300). Three groups were distinguished: group A (n = 92) follow-up at the hospital; group B (n = 84) follow-up by their dentist; group C (n = 46) lost to follow-up.

RESULTS

OLs in group B compared to group A, were smaller in size (<2 cm; p < 0.001), showed more hyperkeratosis (p < 0.001) and less moderate/severe dysplasia (p < 0.001). MT occurred in 45 (20%) patients: 32 (35%) in group A, five (6%) in group B and eight (17%) in group C. There was no significant difference in clinical tumour size between group A (median: 15 mm, range: 1-40) and group B (median: 10 mm, range: 3-25; p = 0.496). Tumour size was smaller for patients in groups A and B (median: 10 mm, range 1-40) compared to group C (median: 33 mm, range: 3-100; p = 0.003). There was a positive correlation between tumour size and interval between the last visit in all patients (p = 0.022).

CONCLUSION

Regular follow-up of OL resulted in early detection of MT. If properly selected, follow-up of OL performed by the dentist seems feasible.

Single-cell transcriptomics dissects premalignant progression in proliferative verrucous leukoplakia

OBJECTIVE

Proliferative verrucous leukoplakia (PVL) is characterized by a spectrum of clinicopathological features and a high risk of malignant transformation. In this study, we aimed to delineate the dynamic changes in molecular signature during PVL progression and identify the potential cell subtypes that play a key role in the premalignant evolution of PVL.

METHODS

We performed single-cell RNA sequencing on three biopsy samples from a large PVL lesion. These samples exhibited a histopathological continuum of PVL progression.

RESULTS

By analyzing the transcriptome profiles of 27,611 cells from these samples, we identified ten major cell lineages and revealed that cellular remodeling occurred during the progression of PVL lesions, including epithelial, stromal, and immune cells. Epithelial cells are shifted to tumorigenic states and secretory patterns at the premalignant stage. Immune cells showed growing immunosuppressive phenotypes during PVL progression. Remarkably, two novel cell subtypes INSR+ endothelial cells and ASPN+ fibroblasts, were discovered and may play vital roles in microenvironment remodeling, such as angiogenesis and stromal fibrosis, which are closely involved in malignant transformation.

CONCLUSION

Our work is the first to depict the cellular landscape of PVL and speculate that disease progression may be driven by functional remodeling of multiple cell subtypes.

Predictive modelling for the diagnosis of oral and laryngeal premalignant and malignant lesions using p53 and Ki-67 expression

Oral and laryngeal epithelial lesions are currently diagnosed using histological criteria based on the World Health Organization (WHO) classification, which can cause interobserver variability. An integrated diagnostic approach based on immunohistochemistry (IHC) would aid in the interpretation of ambiguous histological findings of epithelial lesions. In the present study, IHC was used to evaluate the expression of p53 and Ki-67 in 114 cases of oral and laryngeal epithelial lesions in 104 patients. Logistic regression analysis and decision tree algorithm were employed to develop a scoring system and predictive model for differentiating the epithelial lesions. Cohen's kappa coefficient was used to evaluate interobserver variability, and next-generation sequencing (NGS) and IHC were used to compare TP53 mutation and p53 expression patterns. Two expression patterns for p53, namely, diffuse expression type (pattern HI) and null type (pattern LS), and the pattern HI for Ki-67 were significantly associated with high-grade dysplasia (HGD) or squamous cell carcinoma (SqCC). With an accuracy and area under the receiver operating characteristic curve (AUC) of 84.6% and 0.85, respectively, the scoring system based on p53 and Ki-67 expression patterns classified epithelial lesions into two types: non-dysplasia (ND) or low-grade dysplasia (LGD) and SqCC or HGD. The decision tree model constructed using the p53 and Ki-67 expression patterns classified epithelial lesions into ND, LGD, and group 2, including HGD or SqCC, with an accuracy and AUC of 75% and 0.87, respectively. The integrated diagnosis had a better correlation with near perfect agreement (weighted kappa 0.92, unweighted kappa 0.88). The patterns HI and LS for p53 were confirmed to be correlated with missense mutations and nonsense/frameshift mutations, respectively. A predictive model for diagnosis was developed based on the correlation between TP53 mutation and p53 expression patterns. These results indicate that the scoring system based on p53 and Ki-67 expression patterns can differentiate epithelial lesions, especially in cases when the morphological features are ambiguous.

Predictors of malignant transformation in oral leukoplakia and proliferative verrucous leukoplakia: An observational prospective study including the DNA ploidy status

BACKGROUND

This prospective observational study investigated the determinants of malignant transformation (MT) in localized oral leukoplakia (OL) and proliferative verrucous leukoplakia (PVL).

METHODS

Demographic, clinical, histological, and DNA ploidy status data were collected at enrolment. Survival analysis was performed (MT being the event of interest).

RESULTS

One-hundred and thirty-three patients with OL and 20 patients with PVL entered the study over 6 years (mean follow-up 7.8 years). The presence of OED, DNA ploidy, clinical presentation, and lesion site were associated with MT in patients with OL in a univariate analysis. In a multivariate model, OED was the strongest predictor of MT in patients with OL. Adding DNA ploidy increased the model's predictive power. None of the assessed predictors was associated with MT in patients with PVL.

CONCLUSIONS

DNA ploidy might identify a subset OL with low risk or minimal risk of MT, but it does not seem to be a reliable predictor in patients with PVL.

Streptococcus mitis and Prevotella melaninogenica Influence Gene Expression Changes in Oral Mucosal Lesions in Periodontitis Patients

Oral microbiome disruptions in periodontitis are related to the chronic inflammatory reactions that could in turn lead to the development of multiple oral diseases. The objective of the study was to assess the frequencies of Streptococcus mitis, Prevotella melaninogenica, and Prevotella intermedia in oral benign lesions, oral potentially malignant disorders (OPMDs), and oral squamous cell carcinomas (OSCCs) and investigate the impact of these bacteria on the expression patterns of the selected (potential) target genes (PI3CA/AKT2/mTOR, DUSP16/MAPK14, and COX2). After sample collection (25 benign lesions, 30 OPMDs, and 35 OSCCs) and DNA/RNA extraction, quantitative real-time polymerase chain reaction (qPCR) was performed to detect bacterial presence and assess relative gene expression levels in different lesion groups. Prevotella melaninogenica was the most prevalent of the three analyzed bacteria, with the frequency being 60% in benign lesions, 87% in OPMDs (p = 0.024), and 77% in OSCC. The OPMD tissues in which Prevotella melaninogenica was present exhibited a higher expression level of AKT2 (p = 0.042). Significantly lower expression of DUSP16 was observed in OSCC tissues containing Streptococcus mitis (p = 0.011). The obtained results indicate a substantial contribution of P. melaninogenica and Str. mitis in the pathogenesis of oral mucosal lesions, possibly via AKT2 upregulation and DUSP16 downregulation.

Genome sequencing reveals molecular subgroups in oral epithelial dysplasia

This study aimed to analyze the molecular characteristics of oral epithelial dysplasia (OED), highlighting the pathways and variants of genes that are frequently mutated in oral squamous cell carcinoma (OSCC) and other cancers. Ten archival OED cases were retrieved for retrospective clinicopathological analysis and exome sequencing. Comparative genomic analysis was performed between high-grade dysplasia (HGD) and low-grade dysplasia (LGD), focusing on 57 well-known cancer genes, of which 10 were previously described as the most mutated in OSCC. HGD cases had significantly more variants; however, a similar mutational landscape to OSCC was observed in both groups. CASP8+FAT1/HRAS, TP53, and miscellaneous molecular signatures were also present. FAT1 is the gene that is most affected by pathogenic variants. Hierarchical divisive clustering showed division between the two groups: "HGD-like cluster" with 4HGD and 2LGD and "LGD-like cluster" with 4 LGD. MLL4 pathogenic variants were exclusively in the "LGD-like cluster". TP53 was affected in one case of HGD; however, its pathway was usually altered. We describe new insights into the genetic basis of epithelial malignant transformation by genomic analysis, highlighting those associated with FAT1 and TP53. Some LGDs presented a similar mutational landscape to HGD after cluster analysis. Perhaps molecular alterations have not yet been reflected in histomorphology. The relative risk of malignant transformation in this molecular subgroup should be addressed in future studies.

Changes in the lesion surface suggesting transformation of oral potentially malignant disorders to malignancy - a report of eight cases

BACKGROUND

In the case of oral potentially malignant disorders (OPMD), the possibility of malignant transformation of the lesion necessitates a decision on the need for an additional biopsy at each visit. Among many clinical characteristics, change on the lesion surface is one of the important factors that determine the need for additional biopsy at each visit. The purpose of the study was to provide information on the characteristics of lesions related to malignant transformation during the follow-up period of OPMD.

METHODS

Eight patients (four men and four women) with OPMD that transformed into malignancy during long-term follow-up were included and their mean age was 65.8 ± 12.4 years. Clinical information and histopathological diagnosis were investigated at the initial visit and during the long-term follow-up period. The focus was on information on changes on the lesion surface at the time the lesion was confirmed to be malignant. The period from initial diagnosis to dysplasia and from dysplasia to malignancy was also investigated.

RESULTS

The OPMD diagnoses were oral lichen planus or oral lichenoid lesions (n = 2), oral leukoplakia (n = 5), and hyperplastic candidiasis (n = 1). During the follow-up period of the lesions, when dysplasia was obtained by additional biopsy, changes in the lesions consisted of an increase in the size of the white or red area. The lesion surface of the OPMD showed verrucous, papillary, exophytic, corrugated, and ulcerative changes at the time of malignancy diagnosis. The period for the initial lesion to become dysplasia, from dysplasia to malignancy, and from the initial lesion to malignancy was very variable.

CONCLUSIONS

Attention should be paid to verrucous, papillary, exophytic, corrugated, and ulcerative changes on the lesion surface of OPMD. Considering that the period for OPMD to become malignant is highly variable, a longer follow-up of the lesion is necessary.

Reactive and Nonreactive White Lesions of the Oral Mucosa

White lesions in the oral cavity may be diverse in etiology and may present with significant clinical and sometimes histologic overlap between categories, making accurate diagnosis difficult at times. Although white lesions of immune and infectious etiology are covered in another article, this article discusses the differential diagnosis between developmental, reactive, idiopathic, premalignant, and malignant white lesions focusing on clinical features of each category.

Characterization of initial/early histologic features of proliferative leukoplakia and correlation with malignant transformation: a multicenter study

The aim of this multicenter retrospective study is to characterize the histopathologic features of initial/early biopsies of proliferative leukoplakia (PL; also known as proliferative verrucous leukoplakia), and to analyze the correlation between histopathologic features and malignant transformation (MT). Patients with a clinical diagnosis of PL who have at least one biopsy and one follow-up visit were included in this study. Initial/early biopsy specimens were reviewed. The biopsies were evaluated for the presence of squamous cell carcinoma (SCCa), oral epithelial dysplasia (OED), and atypical verrucous hyperplasia (AVH). Cases that lacked unequivocal features of dysplasia were termed "hyperkeratosis/parakeratosis not reactive (HkNR)". Pearson chi-square test and Wilcoxon test were used for statistical analysis. There were 86 early/initial biopsies from 59 patients; 74.6% were females. Most of the cases had a smooth/homogenous (34.8%) or fissured appearance (32.6%), and only 13.0% had a verrucous appearance. The most common biopsy site was the gingiva/alveolar mucosa (40.8%) and buccal mucosa (25.0%). The most common histologic diagnosis was OED (53.5%) followed by HkNR (31.4%). Of note, two-thirds of HkNR cases showed only hyperkeratosis and epithelial atrophy. A lymphocytic band was seen in 34.8% of OED cases and 29.6% of HkNR cases, mostly associated with epithelial atrophy. Twenty-eight patients (47.5%) developed carcinoma and 28.9% of early/initial biopsy sites underwent MT. The mortality rate was 11.9%. Our findings show that one-third of cases of PL do not show OED with most exhibiting hyperkeratosis and epithelial atrophy, but MT nevertheless occurred at such sites in 3.7% of cases.

Predicting Progression of Oral Lesions to Malignancy Using Machine Learning

OBJECTIVE

To use large-scale electronic health record (EHR) data to develop machine learning models predicting malignant transformation of oral lesions.

METHODS

A multi-institutional health system database was used to identify a retrospective cohort of patients with biopsied oral lesions. The primary outcome was malignant transformation. Chart review and automated system database queries were used to identify a range of demographic, clinical, and pathologic variables. Machine learning was used to develop predictive models for progression to malignancy.

RESULTS

There were 2192 patients with a biopsied oral lesion, of whom 1232 had biopsy proven oral dysplasia. There was malignant transformation in 34% of patients in the oral lesions dataset, and in 54% of patients in the dysplasia subset. Multiple machine learning-based models were trained on the data in two experiments, (a) including all patients with biopsied oral lesions and (b) including only patients with biopsy-proven dysplasia. In the first experiment, the best machine learning models predicted malignant transformation among the biopsied oral lesions with an area under the curve (AUC) of 86%. In the second experiment, the random forest model predicted malignant transformation among lesions with dysplasia with an AUC of 0.75. The most influential features were dysplasia grade and the presence of multiple lesions, with smaller influences from other features including anemia, histopathologic description of atypia, and other prior cancer history.

CONCLUSION

With diverse features from EHR data, machine learning approaches are feasible and allow for generation of models that predict which oral lesions are likely to progress to malignancy.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Oral Epithelial Dysplasia: A Review of Diagnostic Criteria for Anatomic Pathologists

Oral epithelial dysplasia (OED) represents a spectrum of histologic changes in the oral cavity mucosa that has the potential to transform into oral squamous cell carcinoma. Predicting the risk of malignant transformation is predominantly based on clinicopathologic correlation, histologic examination and grading. OED often poses a diagnostic challenge, primarily due to its histologic mimics and a large number of terminologies used in the literature. The grading system for OED is also fraught with significant interobserver variability. This review summarizes the essential clinical and histopathologic features of OED and its mimics. Practical preanalytical, analytical, and postanalytical considerations for anatomic pathologists are discussed to improve the diagnostic accuracy and increase the reproducibility in the grading of OED.

The oral mycobiome: Oral epithelial dysplasia and oral squamous cell carcinoma

Fungi, a diverse group of eukaryotic organisms, play distinct roles in health and disease. Recent advances in the field of mycobiology have enabled the characterization of the "human mycobiome." The human mycobiome has extensively been studied in various disease models. However, to date, the role of the oral mycobiome in oral carcinogenesis has yet to be elucidated. Candida albicans, the most common oral colonizer, has been speculated to display tumorigenic effects; however, the literature lacks consistent documentation from mechanistic studies on whether oral mycobiota act as drivers, facilitators, or passive colonizers of oral premalignancy and cancer. This review article provides an overview of existing hypothesis-driven mechanistic models that outline the complex interplay between the oral mycobiome and oral epithelial dysplasia as well as their potential clinical implications.

Podoplanin Expression Independently and Jointly with Oral Epithelial Dysplasia Grade Acts as a Potential Biomarker of Malignant Transformation in Oral Leukoplakia

Our aim was to evaluate the expression of biomarkers, CD44v6, CD147, EGFR, p53, p63, p73, p16, and podoplanin in oral leukoplakias (OL) and to assess their potential for prediction of malignant transformation (MT). We analyzed the expression of CD44v6, CD147, EGFR, p53, p63, p73, p16, and podoplanin by immunohistochemistry in 52 OL, comprised of 41 low-grade (LG) dysplasia and 11 high-grade (HG) cases. Twelve healthy normal tissues (NT) were also included. Univariate and multivariate analysis were performed to evaluate any association with MT. Variable expression among the studied markers was observed, with a significant increase of high expression from NT to LG and HG cases in CD44v6 (p = 0.002), P53 (p = 0.002), P73 (p = 0.043), and podoplanin (p < 0.001). In multivariate analysis, cases with high podoplanin score showed a significant increased risk of MT (HR of 10.148 (95% CI of 1.503−68.532; p = 0.017). Furthermore, podoplanin combined with binary dysplasia grade obtained a HR of 10.238 (95% CI of 2.06−50.889; p = 0.004). To conclude, CD44v6, p53, p73, and podoplanin showed an increasing expression along the natural history of oral carcinogenesis. Podoplanin expression independently or combined with dysplasia grade could be useful predictive markers of MT in OL.

Immunohistochemical staining patterns of p53 predict the mutational status of TP53 in oral epithelial dysplasia

Next-generation sequencing of oral squamous cell carcinoma (OSCC) has revealed TP53 as the most frequently mutated gene in OSCC mutually exclusive with human papillomavirus infection. Oral epithelial dysplasia (OED) is defined as a precancerous lesion of OSCC by the current World Health Organization (WHO) classification; therefore, it is assumed that TP53 mutations occur in early precancerous conditions such as OED. Here, we conducted an integrated analysis of TP53, including whole coding sequencing of TP53, FISH analysis of the 17p13.1 locus, and immunohistochemical analysis for p53 (p53-IHC), in 40 OED cases. We detected 20 mutations in 16 (40%) OED cases, and four cases, each harbored two mutations. FISH analysis revealed six of 24 cases (25%) had a deletion on 17p13.1, and four cases had concurrent TP53 mutations and 17p13.1 deletion (2-hit). Also, the increased frequency of TP53 mutations in higher degrees of OED implies acquisition of the mutation is a major event toward OSCC. p53-IHC revealed that overall cases could be categorized into four patterns that correlate well with the mutational status of TP53. Especially, two patterns, broad p53 expression type (pattern HI) and p53 null type (pattern LS), strongly correlated with a missense mutation and nonsense mutation, respectively. Furthermore, seven of the 40 cases progressed to SCC, and six of these seven cases presented pattern HI or LS. Therefore, patterns HI and LS have a high risk for malignant transformation if excisional treatment is not performed irrespective of the dysplasia grade. Although the current WHO classification mainly focuses on morphological criteria for the diagnosis of OED, interobserver discrepancy appears in some instances of the OED diagnosis. Our immunohistochemical analysis supports a more accurate pathological diagnosis for OED in cases of low dysplastic changes or of differential diagnosis with non-dysplastic lesions.

Comprehensive Immunoprofiling of High-Risk Oral Proliferative and Localized Leukoplakia

Oral leukoplakia is common and may, in some cases, progress to carcinoma. Proliferative leukoplakia is a progressive, often multifocal subtype with a high rate of malignant transformation compared with the more common localized leukoplakia. We hypothesized that the immune microenvironment and gene expression patterns would be distinct for proliferative leukoplakia compared with localized leukoplakia. We summarize key clinicopathologic features among proliferative leukoplakia and localized leukoplakia and compare cancer-free survival (CFS) between subgroups. We analyze immunologic gene expression profiling in proliferative leukoplakia and localized leukoplakia tissue samples (NanoString PanCancer Immune Oncology Profiling). We integrate immune cell activation and spatial distribution patterns in tissue samples using multiplexed immunofluorescence and digital image capture to further define proliferative leukoplakia and localized leukoplakia. Among N = 58 patients (proliferative leukoplakia, n = 29; localized leukoplakia, n = 29), only the clinical diagnosis of proliferative leukoplakia was associated with significantly decreased CFS (HR, 11.25; P < 0.01; 5-year CFS 46.8% and 83.6% among patients with proliferative leukoplakia and localized leukoplakia, respectively). CD8⁺ T cells and T regulatory (Treg) were more abundant among proliferative leukoplakia samples (P < 0.01) regardless of degree of epithelial dysplasia, and often colocalized to the dysplasia-stromal interface. Gene set analysis identified granzyme M as the most differentially expressed gene favoring the proliferative leukoplakia subgroup (log₂ fold change, 1.93; P _adj < 0.001). Programmed death ligand 1 (PD-L1) was comparatively overexpressed among proliferative leukoplakia samples, with higher (>5) PD-L1 scores predicting worse CFS (P _adj < 0.01). Proliferative leukoplakia predicts a high rate of malignant transformation within 5 years of diagnosis. A prominent CD8⁺ T-cell and Treg signature along with relative PD-L1 overexpression compared with localized leukoplakia provides strong rationale for PD-1/PD-L1 axis blockade using preventative immunotherapy.

Significance

This is the first in-depth profiling effort to immunologically characterize high-risk proliferative leukoplakia as compared with the more common localized leukoplakia. We observed a notable cytotoxic T-cell and Treg signature with relative overexpression of PD-L1 in high-risk proliferative leukoplakia providing a strong preclinical rationale for investigating PD-1/PD-L1 axis blockade in this disease as preventative immunotherapy.

Actinomycosis of the ventral tongue with successful laser ablation therapy: A case report

BACKGROUND

We present a first case report of an Actinomycosis lesion of the ventral tongue. Actinomycosis of the tongue is an uncommon finding.

CASE DESCRIPTION

The 64-year-old female patient presented with a leukoplakic ventral tongue lesion. The diagnosis Actinomycosis was confirmed by histopathologic evaluation. The lesion was successfully treated with antibiotics and laser ablation therapy.

PRACTICAL IMPLICATIONS

Diagnostic and therapeutic concerns are discussed. Clinicians are alerted to considering Actinomycosis within the differential diagnosis of leukoplakic tongue lesions.

Identification of specific clinical risk factors associated with the malignant transformation of oral epithelial dysplasia

BACKGROUND

Factors that increase the risk of malignant transformation of oral epithelial dysplasia (OED) are not completely elucidated.

METHODS

A retrospective chart review was performed assessing risk factors for transformation of OED, and cancer staging for transformed cases at Sunnybrook Health Sciences Centre.

RESULTS

Two-hundred four patients were diagnosed with OED, and 16.7% (34) underwent malignant transformation. Risk factors associated with transformation included: heavy tobacco smoking, excessive EtOH consumption, non-homogenous leukoplakia, size >200 mm² , moderate dysplasia or greater than moderate, progression of dysplasia grades, and immunosuppression. Transformed cases followed for a dysplastic lesion were associated with a stage-I cancer diagnosis, and cancer cases with no prior biopsy were associated with a stage-IV diagnosis.

CONCLUSIONS

In addition to commonly cited risk factors, immunosuppression was associated with malignant transformation, including the use of topical steroids. Analyzing risk factors can help clinicians define risk of progression in patients with OED.

Oral epithelial dysplasia: Recognition, grading and clinical significance

Histopathological grading of epithelial dysplasia remains the principal laboratory method for assessing the risk of malignant transformation in oral potentially malignant disorders (OPMDs). Current views on the molecular pathogenesis and histological interpretation of the features of epithelial dysplasia are described, and the use of grading systems for epithelial dysplasia is discussed. Changes to the current 2017 WHO criteria for diagnosis are proposed with emphasis on the architectural features of epithelial dysplasia. The predictive values of three-grade and binary systems are summarised, and categories of epithelial dysplasia are reviewed, including lichenoid and verrucous lesions, keratosis of unknown significance, HPV-associated dysplasia, differentiated and basaloid epithelial dysplasia. The implications of finding epithelial dysplasia in an oral biopsy for clinical management are discussed from the pathologists' viewpoint.

Malignant Transformation Rate of Non-reactive Oral Hyperkeratoses Suggests an Early Dysplastic Phenotype

The presence of epithelial dysplasia (ED) in oral leukoplakia is the single most important predictor of malignant transformation (MT). The majority of leukoplakias, however, do not show evidence of ED and yet MT of these lesions is well-recognized. These lesions have been referred to as "hyperkeratosis/hyperplasia, no dysplasia," "keratosis of unknown significance" and "hyperkeratosis, not reactive (HkNR)." This study evaluates the MT rate of such leukoplakias. A literature review was performed to identify cohort studies on leukoplakias where (1) there was a recorded histopathologic diagnosis, (2) cases of "hyperkeratosis/hyperplasia, no dysplasia" comprised part of the cohort, and (3) follow-up information was available. There were 9,358 leukoplakias, of which 28.5% exhibited ED while 37.7% consisted of HkNR. Follow-up ranged from 15 to 73 months. The incidence of MT in leukoplakia exhibiting HkNR was 4.9%, compared to 15.3% for ED. Among oral squamous cell carcinomas (SCC) with previously biopsied, site-specific precursor lesions, 55.7% arose from ED/carcinoma in situ and 28.0% arose from HkNR. Leukoplakia exhibiting HkNR has a substantial MT rate, similar to that of mild ED, and must be recognized and managed appropriately to reduce oral SCC incidence.

Gingival Leukoplakia: Hyperkeratosis with Epithelial Atrophy Is A Frequent Histopathologic Finding

White lesions on the gingiva and palatal mucosa may represent reactive keratoses, including specific diseases such as benign alveolar ridge keratosis, or nonreactive keratoses, such as true leukoplakia, the latter being associated with a high recurrence rate at this site. The aim of this study is to determine the histopathologic features of gingival keratoses. Hyperkeratotic lesions from the gingiva, palatal mucosa, and alveolar ridge mucosa were available for evaluation after excluding specific keratotic lesions such as candidiasis. There were 321 biopsies from 296 patients and approximately half of the cases (159/321, 49.5%) were reactive keratoses. The rest of the 162 biopsies from 149 patients (76 females; 51.0%) represented true leukoaplakias. The most common location was the gingiva (73.2%) followed by the palatal mucosa (17.0%). Hyperkeratosis/parakeratosis not reactive (HkNR) represented 43.8% of cases; 45.7% were dysplasia or carcinoma, and the rest were not readily classifiable as reactive or non-reactive keratoses. Histopathologic features commonly noted in the HkNR lesions include sharp demarcation (72.7%), corrugated surface (53.5%), and epithelial atrophy (48.1%). A lymphocytic band was noted in 8.5% of the cases, mostly associated with epithelial atrophy (5/6 cases). Seven patients with 17 biopsies from noncontiguous sites likely had proliferative leukoplakia; the most common location was the gingiva (88.2%) and the most common diagnosis was HkNR (52.9%). HkNR is a common histopathologic diagnosis for leukoplakias on the gingiva, and these lesions frequently exhibit thick hyperkeratosis, epithelial atrophy and a lymphocytic band at the interface.

Oral leukoplakia, leukoerythroplakia, erythroplakia and actinic cheilitis: Analysis of 953 patients focusing on oral epithelial dysplasia

BACKGROUND

To analyse the clinical and histological characteristics from a series of oral leukoplakias, leukoerythroplakias, erythroplakias and actinic cheilitis diagnosed in a 14-year period.

METHODS

The files were reviewed and all cases diagnosed as leukoplakia, leukoerythroplakia, erythroplakia and actinic cheilitis were selected. Clinical information was obtained from the biopsy submission forms, and histological review was performed in all cases.

RESULTS

Final sample included 953 lesions, mostly affecting females (534, 56%), and 87.5% of the patients were 41 to 80 years old. The most commonly affected regions were the lower lip (20.1%), tongue (18.1%) and buccal mucosa (16.9%). Leukoplakias, actinic cheilitis, leukoerythroplakias and erythroplakias represented, respectively, 74.6%, 15.2%, 9.3% and 0.8% of the sample. Most cases presented no dysplasia (42.1%) or mild dysplasia (33.5%). Lesions in the tongue, floor of mouth and lower lip, as well as lesions that presented hyperparakeratosis, showed higher frequencies of moderate dysplasia and severe dysplasia/carcinoma in situ. The most common histological criteria were the increase in number and size of nucleoli, loss of polarity of the basal cells and variations in cellular size and shape. Classification by the binary system showed that 7% were high-risk lesions.

CONCLUSION

All histological criteria for classification of oral epithelial dysplasia recommended by the World Health Organization showed increased frequency as grading increased. Additional criteria seem to be useful in grading oral epithelial dysplasia, such as the presence of normal and abnormal superficial mitotic figures and endophytic epithelial proliferation.

Oral Potentially Malignant Disorders (OPMD): What is the clinical utility of dysplasia grade?

INTRODUCTION

Oral epithelial dysplasia is considered a potential histologic precursor of subsequent squamous cell cancer. As standard clinical practice, pathologists grade dysplasia to assess risk for progression to malignancy. Except for the most advanced grade, severe dysplasia, dysplasia grading has failed to correlate well with the risk to develop invasive cancer. The questions of what process dysplasia grading best represents and what clinical utility dysplasia grading may have are explored.

AREAS COVERED

This narrative review is based on PubMed search with emphasis on papers since 2010. Epithelial dysplasia as a precursor lesion of cancer and dysplasia grading as a risk assessment tool for progression to cancer are discussed. The close clinical association of dysplasia with known carcinogens, alcohol, and tobacco products is presented.

EXPERT OPINION

Oral epithelial dysplasia is often, associated with prolonged exposure to tobacco and alcohol products. With reduction of carcinogen exposure, dysplasia is known to regress in some cases. It is proposed that histologic dysplasia grade together with macroscopic images of dysplastic clinical lesions be used as an educational tool to incentivize patients to reduce their known carcinogen exposure. This strategy has the potential to reduce lesion progression thereby reducing the disease burden of oral cancer.

Proliferative Verrucous Leukoplakia: An Expert Consensus Guideline for Standardized Assessment and Reporting

The many diverse terms used to describe the wide spectrum of changes seen in proliferative verrucous leukoplakia (PVL) have resulted in disparate clinical management. The objective of this study was to produce an expert consensus guideline for standardized assessment and reporting by pathologists diagnosing PVL related lesions. 299 biopsies from 84 PVL patients from six institutions were selected from patients who had multifocal oral leukoplakic lesions identified over several years (a minimum follow-up period of 36 months). The lesions demonstrated the spectrum of histologic features described in PVL, and in some cases, patients developed oral cavity squamous cell carcinoma (SCC). An expert working group of oral and maxillofacial and head and neck pathologists reviewed microscopic features in a rigorous fashion, in combination with review of clinical photographs when available. The working group then selected 43 single slide biopsy cases for whole slide digital imaging (WSI) review by members of the consensus conference. The digital images were then reviewed in two surveys separated by a washout period of at least 90 days. Five non-PVL histologic mimics were included as controls. Cases were re-evaluated during a consensus conference with 19 members reporting on the cases. The best inter-observer diagnostic agreement relative to PVL lesions were classified as "corrugated ortho(para)hyperkeratotic lesion, not reactive" and "SCC" (chi-square p = 0.015). There was less than moderate agreement (kappa < 0.60) for lesions in the "Bulky hyperkeratotic epithelial proliferation, not reactive" category. There was ≥ moderate agreement (> 0.41 kappa) for 35 of 48 cases. This expert consensus guideline has been developed with support and endorsement from the leadership of the American Academy of Oral and Maxillofacial Pathology and the North American Society of Head and Neck Pathologists to recommend the use of standardized histopathologic criteria and descriptive terminology to indicate three categories of lesions within PVL: (1) "corrugated ortho(para)hyperkeratotic lesion, not reactive;" (2) "bulky hyperkeratotic epithelial proliferation, not reactive;" and (3) "suspicious for," or "squamous cell carcinoma." Classification of PVL lesions based on a combination of clinical findings and these histologic descriptive categories is encouraged in order to standardize reporting, aid in future research and potentially guide clinical management.

Oral potentially malignant disorders: A consensus report from an international seminar on nomenclature and classification, convened by the WHO Collaborating Centre for Oral Cancer

Oral potentially malignant disorders (OPMDs) are associated with an increased risk of occurrence of cancers of the lip or oral cavity. This paper presents an updated report on the nomenclature and the classification of OPMDs, based predominantly on their clinical features, following discussions by an expert group at a workshop held by the World Health Organization (WHO) Collaborating Centre for Oral Cancer in the UK. The first workshop held in London in 2005 considered a wide spectrum of disorders under the term "potentially malignant disorders of the oral mucosa" (PMD) (now referred to as oral potentially malignant disorders: OPMD) including leukoplakia, erythroplakia, proliferative verrucous leukoplakia, oral lichen planus, oral submucous fibrosis, palatal lesions in reverse smokers, lupus erythematosus, epidermolysis bullosa, and dyskeratosis congenita. Any new evidence published in the intervening period was considered to make essential changes to the 2007 classification. In the current update, most entities were retained with minor changes to their definition. There is sufficient evidence for an increased risk of oral cancer among patients diagnosed with "oral lichenoid lesions" and among those diagnosed with oral manifestations of 'chronic graft-versus-host disease'. These have now been added to the list of OPMDs. There is, to date, insufficient evidence concerning the malignant potential of chronic hyperplastic candidosis and of oral exophytic verrucous hyperplasia to consider these conditions as OPMDs. Furthermore, due to lack of clear evidence of an OPMD in epidermolysis bullosa this was moved to the category with limited evidence. We recommend the establishment of a global research consortium to further study the natural history of OPMDs based on the classification and nomenclature proposed here. This will require multi-center longitudinal studies with uniform diagnostic criteria to improve the identification and cancer risk stratification of patients with OPMDs, link them to evidence-based interventions, with a goal to facilitate the prevention and management of lip and oral cavity cancer.

Annual malignant transformation rate of oral leukoplakia remains consistent: A long-term follow-up study

OBJECTIVES

Numerous clinical and histopathological characteristics have been associated with malignant transformation (MT) of oral leukoplakia (OL), including classic and differentiated epithelial dysplasia, but MT predictions remain suboptimal. The objective of this study was to determine the annual MT rate of OL and to identify clinicopathological risk factors associated with MT.

PATIENTS AND METHODS

170 patients with OL were included in this retrospective cohort study, 117 females and 53 males. Follow-up ranged from 12 to 219 months (median 54). The analyzed variables included age, gender, smoking habits, clinical presentation, subsite, size and treatment. In a subgroup of 140 patients, histopathological diagnoses were reviewed with regard to the presence of dysplasia, discerning both classic dysplasia and differentiated dysplasia.

RESULTS

MT occurred in 23% of the patients, resulting in an annual MT rate of 4.9% (95% CI: 3.5 - 6.6) which remained consistent. High-risk subsite (tongue and floor of mouth) was the only clinical predictor for MT (Hazard Ratio = 2.7, 95% CI: 1.3 - 5.5, p = 0.007). In 140 patients, classic dysplasia (Hazard Ratio = 7.2, 95% CI: 1.6 - 33.1, p = 0.012) and differentiated dysplasia (Hazard Ratio = 6.6, 95% CI: 1.2 - 25.4, p = 0.026) were predictors for MT. Binary grading between dysplasia and no dysplasia was significant for predicting MT (Hazard Ratio = 6.4, 95% CI: 1.5 - 27.5, p = 0.013).

CONCLUSION

Since annual MT rate of OL remains stable during follow-up, regular long-term or even life-long follow-up is advocated. Specific oral subsites and epithelial dysplasia are predictors for MT of OL.

Architectural Alterations in Oral Epithelial Dysplasia are Similar in Unifocal and Proliferative Leukoplakia

The current WHO histopathologic criteria for oral epithelial dysplasia (ED) are based on architectural and cytologic alterations, and do not address other histopathologic features of ED. Here we propose new diagnostic criteria including architectural, organizational, and cytologic features for oral ED. Cases of unifocal leukoplakia (UL) and proliferative leukoplakia (PL) with clinical photographs and follow-up information were identified. Only cases that showed minimal cytologic atypia or mild ED were used to demonstrate critical architectural changes as defined in this study. Eight biopsies from eight UL patients and 34 biopsies from four PL patients were included. The biopsies showed (a) corrugated, verrucous or papillary architecture, (b) hyperkeratosis with epithelial atrophy, (c) bulky squamous epithelial proliferation, and (d) demarcated hyperkeratosis and "skip" segments. The architectural alterations defined here are as important as the currently used criteria for the diagnosis of ED. Clinicopathologic correlation when diagnosing oral ED is also of the utmost importance in accurate diagnosis.

Molecular, genomic and mutational landscape of oral leukoplakia

Oral leukoplakia (OLK) and its more aggressive clinical variant proliferative verrucous leukoplakia (PVL) remain enigmatic disorders clinically and histopathologically. Despite decades of research into both, there has been only incremental advancement in our understanding of their aetiology and pathogenesis and only minimal improvement in effective management strategies. Currently, no specific prognostic genetic or molecular marker has been reported for leukoplakia. There is, however, an emerging body of evidence characterising the genomic and transcriptomic profile of OLK. Regardless of the significance of cellular and architectural features of OLK and PVL, it is clear from studies reported in this review that new emerging evidence points to the presence of premalignant molecular subtypes of leukoplakia which require further investigation. This up-to-date review explores the contemporary genomic, transcriptomic and mutational landscape of leukoplakia broadly, discusses concepts that may not be widely recognised or accepted and purposefully highlights studies with juxtaposed findings in an effort to challenge dogma. It also highlights the urgent need for a concerted international effort of original collaborative research which will only occur by pooling collective efforts, resources and intellect to define the molecular fingerprint of this enigmatic disorder, in the hope it will better inform diagnosis, stratification and treatment.

Oral epithelial reactive atypia/dysplasia: An underestimated true atypia/dysplasia?

Several clinical and histological features, usually associated with chronic inflammation could complexify the diagnosis of oral epithelial dysplasia (OED). These changes in response to inflammatory stimuli, or re-epithelialization events, are described as reactive epithelial atypia or dysplasia (REA/D). Within a REA/D scenario (for example in the edges of chronic traumatic ulcers), the diagnosis of OED could be challenging for oral pathologists due to an unfeasibility to accurate the true nature of that changes. Due to a reactive profile, REA/D suggests an evolutionary pattern of reversibility once the source that generates those changes is suppressed. However, there are no studies that address the nature or evolution of REA/D. In this context, how might reactive atypia diagnosis modify the therapeutic approach of an oral condition? Could the follow-up protocol of an oral lesion be modified with a diagnosis of REA/D? We hypothesized that there are epithelial changes, usually diagnosed as REA/D in a context of inflammation and chronic irritation, whose dysplastic potential is underestimated, or at least unknown. A biased pathophysiological conception could lead to erroneous or insufficient decisions, especially in the follow-up of these cases. The link between chronic inflammation and carcinogenesis is unquestionable. Oral mucosa is frequently exposed to inflammatory sources. Many conditions such as oral lichen planus, lichenoid lesions, and non-healing chronic traumatic ulcers were previously related to oral carcinogenesis. The diagnosis of REA/D within these entities is often underestimated. However, experimental models and epidemiological studies demonstrated that precursor lesions of some malignancies were initially diagnosed as reactive changes. Furthermore, a subset of oral reactive lesions associated with chronic mechanical irritation showed early carcinogenesis biomarkers. Nevertheless, further studies are needed to understand this issue. The controversial terminology Reactive Atypia vs True Atypia was also a debatable topic in other fields of medical evidence. Since some patients may not fit the strict criteria diagnosis given for each disease, we proposed the term: Oral Epithelial Atypia of Unknown Significance to characterize cellular and dysplastic changes possibly related to chronic inflammation but without a true certainty of its evolution. This term could encourage the clinician to perform a careful follow up of cases of REA/D and also readdress the focus of research regarding oral carcinogenesis. Finally, if all microscopic findings linked to inflammation are diagnosed as REA/D, may lead to underestimation of the potential of inflammation in the multifactorial context of oral carcinogenesis.

Marginal linear gingival leukoplakia progressing to "ring around the collar"-An ominous sign of proliferative verrucous leukoplakia

BACKGROUND

Potentially malignant lesions of the gingiva may frequently present as well-demarcated white lesions confined to the marginal gingiva. These lesions often become thick and verrucoid and spread along the marginal gingiva to encircle the tooth. Some cases of marginal gingival leukoplakia, over time, progress to extensively involve the gingiva fulfilling the criteria for proliferative verrucous leukoplakia (PVL). The objective of this study is to raise awareness of this pattern of leukoplakia by reporting a series of cases of marginal gingival leukoplakia.

METHODS

An Institutional Review Board approved retrospective search of University of Florida and University of Nebraska Medical Center oral biopsy services was performed for all gingival biopsies. Inclusion criteria included cases exhibiting marginal gingival leukoplakia, and with accompanying clinical images.

RESULTS

A total of 30 cases of marginal gingival leukoplakia were included. All cases presented as well-demarcated leukoplakias, either on the buccal or lingual gingival margin, or circumferentially forming a "ring around the collar" of single or multiple teeth. Eight patients had recurrent lesions and 12 had multifocal involvement. Six of the 12 patients with multifocal involvement presented with a "ring around the collar." The histopathologic diagnoses were representative of benign lesions in seven cases, premalignant in 13, and malignant or suggestive of malignancy in 10 cases. Seven patients had carcinoma at the time of first biopsy, whereas 6 cases showed progression at time of follow-up.

CONCLUSION

This study aims to raise awareness that marginal gingival leukoplakia may represent potentially malignant lesions, and if circumferential and/or thick, may be the first manifestation of PVL.

Association between hyperglycemia and the malignant transformation of oral leukoplakia in China

OBJECTIVES

This study aimed to examine the association between hyperglycemia and the malignant transformation of oral leukoplakia (OLK).

PATIENTS AND METHODS

This retrospective case-control study involved 133 patients with the malignant transformation of OLK into oral squamous cell carcinoma (case group) and 266 patients with untransformed OLK (control group). The clinical history and follow-up data included age, gender, lesion size and location, and fasting plasma glucose. Logistic regression analysis, Kaplan-Meier survival analysis, and univariate and multivariate Cox regression analyses were used to assess the effects of risk factors on the malignant transformation of OLK.

RESULTS

Hyperglycemia (adjusted hazard ratio [AHR] = 4.7, p = .001), non-homogenous OLK (AHR = 3.0, p < .001), location of the lesion on the ventral surface of the tongue or floor of the mouth (AHR = 3.6, p < .001), and epithelial dysplasia (AHR = 2.8, p = .005) had significant effects on the malignant transformation of OLK.

CONCLUSION

Hyperglycemia, non-homogenous OLK, location of the lesion on the ventral surface of the tongue or floor of the mouth, and epithelial dysplasia might be associated with malignant transformation of OLK.

Benign Alveolar Ridge Keratosis: Clinical and Histopathologic Analysis of 167 Cases

Benign alveolar ridge keratosis (BARK), the intraoral counterpart of cutaneous lichen simplex chronicus, is a reactive hyperkeratosis caused by trauma or friction that presents as a poorly demarcated white papule or plaque on the keratinized mucosa of the retromolar pad or alveolar ridge mucosa (often edentulous). This is a clinical and histopathologic analysis of BARK including evaluation of p53 expression in selected cases. One hundred and sixty-seven cases of BARK were identified from 2016 to 2017 and 112 (67.1%) occurred in males with a median age of 56 years (range 15-86). The retromolar pad was affected in 107 (64.1%) cases and the edentulous alveolar mucosa in 60 (35.9%) cases, with 17.4% of the cases presenting bilaterally. BARK showed hyperkeratosis often with wedge-shaped hypergranulosis and occasional focal parakeratosis. The epithelium exhibited acanthosis and surface corrugation with tapered rete ridges often interconnected at the tips. The study for p53 performed in 12 cases showed less than 25% nuclear positivity. BARK is a distinct benign clinicopathologic entity caused by friction, which should be clearly distinguished from true leukoplakia, a potentially malignant disorder.

Incorporation of differentiated dysplasia improves prediction of oral leukoplakia at increased risk of malignant progression

Oral leukoplakia is the most common oral potentially malignant disorder with a malignant transformation rate into oral squamous cell carcinoma of 1-3% annually. The presence and grade of World Health Organization defined dysplasia is an important histological marker to assess the risk for malignant transformation, but is not sufficiently accurate to personalize treatment and surveillance. Differentiated dysplasia, known from differentiated vulvar intraepithelial neoplasia, is hitherto not used in oral dysplasia grading. We hypothesized that assessing differentiated dysplasia besides World Health Organization defined (classic) dysplasia will improve risk assessment of malignant transformation of oral leukoplakia. We investigated a retrospective cohort consisting of 84 oral leukoplakia patients. Biopsies were assessed for dysplasia presence and grade, and the expression of keratins 13 (CK13) and 17, known to be dysregulated in dysplastic vulvar mucosa. In dysplastic oral lesions, differentiated dysplasia is as common as classic dysplasia. In 25 out of 84 (30%) patients, squamous cell carcinoma of the upper aerodigestive tract developed during follow-up. Considering only classic dysplasia, 11 out of 56 (20%) patients with nondysplastic lesions progressed. With the incorporation of differentiated dysplasia, only 2 out of 30 (7%) patients with nondysplastic lesions progressed. The risk of progression increased from 3.26 (Hazard ratio, p = 0.002) when only classic dysplasia is considered to 7.43 (Hazard ratio, p = 0.001) when classic and differentiated dysplasia are combined. Loss of CK13, combined with presence of dysplasia, is associated with greater risk of malignant progression (p = 0.006). This study demonstrates that differentiated dysplasia should be recognized as a separate type of dysplasia in the oral mucosa and that its distinction from classic dysplasia is of pathological and clinical significance since it is a strong (co)prognostic histopathological marker for oral malignant transformation. In oral lesions without dysplasia and retained CK13 staining the risk for progression is very low.

Oral leukoplakia; a proposal for simplification and consistency of the clinical classification and terminology

There is a distinct lack of uniformity in the definitions and clinical terminologies related to oral leukoplakia and leukoplakialike lesions and disorders. Proposals have been put forward to subclassify leukoplakia into a homogeneous and a non-homogeneous type based on color only, being either predominantly white or mixed white-and-red, respectively, irrespective of the texture of the lesion. In this proposal there is no need anymore to regard the poorly defined proliferative verrucous leukoplakia as a separate entity. Since keratosis is primarily a histopathological term, its clinical use is discouraged. Alternative terminology for these so-called keratotic lesions and disorders has been put forward. Finally, a suggestion has been made to rename the term hairy leukoplakia, being a well defined, not potentially malignant disorder particularly related to HIV-infection, into 'EBV-positive white lesion of the tongue' (EBVposWLT).

Key words:Potentially malignant oral disorders, oral leukoplakia, oral keratosis, hairy leukoplakia.

Oral keratosis of unknown significance shares genomic overlap with oral dysplasia

OBJECTIVES

To identify molecular characteristics of keratosis of unknown significance and to nominate pathways of molecular progression to oral cancer. Our work could provide a rationale for monitoring and treating these lesions definitively.

METHODS

Patients with oral leukoplakia were eligible for our prospective observational study. We correlated alterations in cancer-associated genes with clinical and histopathologic variables (keratosis of unknown significance vs. moderate-to-severe dysplasia) and compared these alterations to a previously molecularly characterized oral cancer population.

RESULTS

Of 20 enrolled patients, 13 (65%) had evidence of keratosis of unknown significance, while seven (35%) had dysplasia. Nine patients (45%) developed oral cancer (4/13 with keratosis of unknown significance, 5/7 with dysplasia). At a median follow-up of 67 (range 22-144) months, median overall survival was significantly shorter for patients with dysplasia (hazard ratio 0.11, p = .02). KMT2C and TP53 alterations were most frequent (75% and 35%, respectively). There were molecular similarities between keratosis of unknown significance and dysplasia patients, with no significant differences in mutational frequency among genes with ≥15% rate of alteration.

CONCLUSIONS

Among patients with leukoplakia, both patients with keratosis of unknown significance and patients with dysplasia developed oral cancer. Molecular alterations between these two groups were similar at this sample size.

Oral Epithelial Dysplasia and Premalignancy

Leukoplakia and erythroplakia are two entities under the moniker of "oral potentially malignant disorders" that are highly associated with the presence of oral epithelial dysplasia (OED) at first biopsy, while lesions of submucous fibrosis develop OED after being present for years. Importantly, traumatic/frictional keratoses are often mistaken clinically for leukoplakia and it is important for the pathologist to recognize and report them as such. The features of OED have been well-described and other architectural features will be discussed here, in particular verrucous and papillary architecture, bulky epithelial proliferation and epithelial atrophy. Proliferative leukoplakia, verrucous or otherwise, often show only hyperkeratosis in early lesions, with development of OED occurring over time, and squamous cell carcinoma developing in the majority of cases over time. The concept of hyperkeratosis without features of OED and that is not reactive, is likely a precursor to the dysplastic phenotype. Many cases of leukoplakia exhibiting OED are associated with a band of lymphocytes at the interface and these should not be mistaken for oral lichen planus.

Frictional Keratosis, Contact Keratosis and Smokeless Tobacco Keratosis: Features of Reactive White Lesions of the Oral Mucosa

White lesions of the oral cavity are quite common and can have a variety of etiologies, both benign and malignant. Although the vast majority of publications focus on leukoplakia and other potentially malignant lesions, most oral lesions that appear white are benign. This review will focus exclusively on reactive white oral lesions. Included in the discussion are frictional keratoses, irritant contact stomatitis, and smokeless tobacco keratoses. Leukoedema and hereditary genodermatoses that may enter in the clinical differential diagnoses of frictional keratoses including white sponge nevus and hereditary benign intraepithelial dyskeratosis will be reviewed. Many products can result in contact stomatitis. Dentrifice-related stomatitis, contact reactions to amalgam and cinnamon can cause keratotic lesions. Each of these lesions have microscopic findings that can assist in patient management.

The Effectiveness of Laser-Assisted Surgical Excision of Leukoplakias and Hyperkeratosis of Oral Mucosa: A Case Series in A Group of Patients

Introduction: In the different branches of dentistry, the use of laser to solve different clinical situations is increasing due to numerous advantages that have been studied in literature since the 70s. Leucoplakia and hyperkeratosis can benefit from laser-assisted treatment. In most cases biopsy sampling, histological examination and, if no malignant cells are present, the follow-up is needed. However, even if the lesion is free of dysplasia patients often ask to eliminate these white spots that are always a cause of concern. Aim: From these numerous requests comes the idea of setting up a laser-assisted protocol as less invasive as possible to be offered to patients. The aim of the study is to find a laser-assisted protocol for the surgical excision of leucoplakia and hyperkeratosis that can both improve the clinical aspect of the lesion and be sustainable for patients. The null hypothesis has been identified in the following statement: the treatment is effective and efficient at the same time; where effectiveness was tested with the following criteria: size of the lesion, tactile perception, discomfort, pain; and efficiency with the following criteria: pain and discomfort perceived during the treatment. Materials and methods: To collect all data, a specially designed medical record was used. The diode laser was used with a pulsed mode and the maximum power corresponds to 1.8 W. No anaesthesia was used. Before laser-assisted treatment, the fibre was activated and was used with a contact overflowing. Results: Our results show a decrease in the size of the lesion statistically significant. No pain was referred during treatment, except for a slight burning sensation. Conclusion: In conclusion we can state that the treatment is both efficient and effective.

Oral leukoplakia remains a challenging condition

Crispian Scully had many interests in the realm of oral diseases. But oral leukoplakia was one that piqued his curiosity when he was still an academic neophyte and remained a topic which he studied throughout his enormously productive career. It is easy to understand why. While the clinical manifestations of oral leukoplakia are common, we still do not fully understand why one version of the condition is benign, while another, similar in appearance, progresses to a malignancy. The diagnosis of oral leukoplakia is based on expert clinical and histopathological examamination. Management and treatment of leukoplakia remain challenging especially for large lesions and the proliferative subtype. This review aims to provide a general overview on leukoplakia, explore current challenges in its diagnosis and management and discuss the opportunities to better understand the condition.

Proliferative leukoplakia: Proposed new clinical diagnostic criteria

OBJECTIVE

We aimed to characterize proliferative verrucous leukoplakia (PVL) from a clinical and histopathological standpoint and suggest an updated classification.

SUBJECTS AND METHODS

Records of patients seen at three oral medicine centers with a clinical diagnosis of PVL were reviewed for clinical and histopathological features and malignant transformation (MT).

RESULTS

There were 42 patients (median age: 69 years [range: 36-88]; 35 females). 12.2% were current smokers. Family history of cancer was present in 43.7% of patients. Partial demarcation of lesion margins was present in 31.3% of lesions, followed by verrucous (27.5%), smooth (22.7%) erythematous (22.3%), and fissured (18.3%) appearance. Large and contiguous and multisite and non-contiguous lesions comprised 57.1% (24/42) and 35.7% (15/42) of PVL cases, respectively. 19.1% had prominent erythema (erythroleukoplakia). The most common histopathological diagnosis at first visit was hyperkeratosis without dysplasia (22/42; 56.4%). MT occurred in 71.4% patients after a median of 37 months [range: 1-210] from initial visit; erythroleukoplakia exhibited MT in 100% of cases.

CONCLUSION

The generic term "proliferative leukoplakia (PL)" may be more appropriate than PVL because 18.3% were fissured and 22.7% erythematous. We also propose the term proliferative erythroleukoplakia to more accurately describe the subset of PL with prominent erythema, which had the highest MT rate.

Intraoral Potentially Malignant Disorders in a Brazilian Oral Pathology Service: Epidemiological, Clinical, and Histopathological Findings

The aim of this study was to investigate the characteristics of individuals with intraoral potentially malignant disorders (IOPMD) in an oral pathology service in Brazil. Cases were screened based on clinical diagnosis of leukoplakia (LKP), erythroleukoplakia (ELKP), and erythroplakia (EP). Clinical data and information regarding associated factors were gathered from biopsy reports. Histological diagnoses were collected from histopathological records. Among 208 IOPMD cases, 84.13% involved LKP; 11.1%, ELKP; and 4.8%, EP. The most affected sites were the gingiva and buccal mucosa. Histologically, epithelial dysplasia was present in 66.8% of the lesions, acanthosis and hyperkeratosis without epithelial dysplasia were present in 27.9%, and squamous cell carcinoma was present in 2.9%. Most patients were males, fair-skinned, with mean age of 53.4 years. Chronic smokers represented 73% of subjects, of which 30% also consumed alcohol. Smokers and drinkers were mostly males (p < 0.001). EP and ELKP represented histologically more severe degrees of epithelial dysplasia than LKP (p < 0.001). In conclusion, individuals with IOPMD were more frequently fair-skinned men in the sixth decade of life, with smoking habit. Special attention is required to clinical diagnoses of ELKP and EP since the prevalence of severe epithelial dysplasia, in situ carcinoma, and squamous cell carcinoma is higher than in LKP.

PI3K-AKT-mTOR pathway proteins are differently expressed in oral carcinogenesis

BACKGROUND

PI3K-AKT-mTOR signaling pathway is associated with several cellular functions and is frequently changed in several malignancies. The aim of this study was to characterize the immunohistochemical expression pattern of components in PI3K-AKT-mTOR signaling pathway in oral epithelial dysplasia (OED), comparing to oral squamous cell carcinoma (OSCC) and non-dysplastic oral tissues (NDOT).

METHODS

A total of 186 cases of NDOT, OED and OSCC were retrieved. Nuclear staining and cytoplasmic staining of the keratinocytes were considered positive, and the percentage of positive cells was calculated.

RESULTS

Increased immunoreactivity from NDOT to OED and OSCC was seen for all proteins. In NDOT cases, positivity was found only for pS6 (52.9%) and p4EBP1 (13.5%). In OED, immunoreactivity was observed for pAKT (62.2%), pmTOR (28.6%), pS6 (70.8%), and p4EBP1 (42.9%). In OSCC cases, immunoreactivity was found for pAKT (83.3%), pmTOR (50%), pS6 (77.4%), and p4EBP1 (50%). The pAKT and pmTOR expression was higher in OED (<0.001, Fisher's exact test) and OSCC (<0.001, Fisher's exact test).

CONCLUSION

Our study demonstrated higher pAKT and pmTOR expression during carcinogenesis of oral mucosa, differing considerably among OED and OSCC specimens when compared to NDOT. These proteins can be considered potential diagnostic markers for early detection of cancer.