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

Smokeless tobacco keratosis in oral mucosa with epithelial dysplasia: A case report

RATIONALE

Smokeless tobacco use is a risk factor for the development of various oral lesions, among which is smokeless tobacco keratosis (STK). This condition is caused by constant frictional irritation of smokeless tobacco products against the oral mucosa and appears as a White-to-gray plaque with wrinkling.

PATIENT CONCERNS

A 50-year-old man who had been using smokeless tobacco for 24 years visited our clinic complaining of changes in the lower right sulcus of the oral cavity for 10 days. Clinical examination revealed a unilateral, nonhomogeneous White lesion in the area of the complaint. Histopathological examination showed hyperkeratosis, areas of keratin plugging, and mild dysplastic epithelial changes.

DIAGNOSIS

The clinico-histopathological correlation suggested a diagnosis of STK with focal mild epithelial dysplasia.

INTERVENTION AND OUTCOME

A comprehensive management plan included maintaining oral hygiene, education on the detrimental effects of smokeless tobacco, advice to cease smoking, and regular follow-up to monitor the potential for malignant transformation. The patient was referred to a tobacco cessation society for tailored advice and counseling. On follow-up visits, there was an improvement in the lesion after habitual cessation.

LESSONS

The diagnosis of tobacco-related oral lesions is often delayed, which may result in malignant transformation. This illustrates the need to train healthcare professionals to identify tobacco-related conditions at an early stage and to educate patients regarding the harmful effects of tobacco use.

Evaluation of Oral Mucosal Lesions in Iranian Smokers and Non-smokers

BACKGROUND

Tobacco smoking statistics are alarming and the oral mucosa is the first human part of the body that is exposed to the toxic substances of smoking.

AIMS

Considering the high prevalence rate of tobacco-associated problems in the oral cavity and few studies on the Iranian population regarding the effects of smoking on the oral cavity, this study aimed to evaluate the relationship between smoking and oral lesions in the Iranian population.

MATERIALS AND METHODS

Observational study. In this observational study, the oral cavities of 200 participants (smokers = 100 and non-smokers = 100) were examined by a trained dental student under the supervision of an oral and maxillofacial medicine expert, and the presence of coated tongue, leukoedema, leukoplakia, smoker's palate, smoker's melanosis, erythroplakia, frictional hyperkeratosis, acute pseudomembranous candidiasis, and erythematous candidiasis were recorded. Xerostomia was evaluated based on participants' self-reporting through a questionnaire. All data were analyzed using T-test, Chi-square test, odd ratio, 95% confidence interval, Fisher's exact test, and Spearman's rank correlation coefficient.

RESULTS

The results of this study showed smoking is significantly associated with an increased risk of coated tongue (OR: 1.80, 95% CI: 1.32-3.54, P = 0.005), smoker's melanosis (OR: 6.176, 95% CI: 3.28-11.62, P = 0.00002), and frictional hyperkeratosis (OR: 1.33, 95% CI: 0.68-2.60, P = 0.005). However, no significant association was observed between smoking and leukoedema (OR: 1, 95% CI: 0.51-1.94, P = 1). None of the participants presented smoker's palate, erythroplakia, and candidiasis.

CONCLUSIONS

This study's results showed that smokers exhibited a greater chance of developing oral lesions compared to non-smokers.

Demystifying oral epithelial dysplasia: a histological guide

Oral epithelial dysplasia is a histologically diagnosed potentially premalignant disorder of the oral mucosa, which carries a risk of malignant transformation to squamous cell carcinoma. The diagnosis and grading of oral epithelial dysplasia is challenging, with cases often referred to specialist oral and maxillofacial pathology centres for second opinion. Even still there is poor inter-examiner and intra-examiner agreement in a diagnosis. There are a total of 28 features of oral epithelial dysplasia listed in the 5th edition of World Health Organization classification of tumours of the head and neck. Each of these features is poorly defined and subjective in its interpretation. Moreover, how these features contribute to dysplasia grading and risk stratification is even less well defined. This article discusses each of the features of oral epithelial dysplasia with examples and provides an overview of the common mimics, including the normal histological features of the oral mucosa which may mimic atypia. This article also highlights the paucity of evidence defining these features while offering suggested definitions. Ideally, these definitions will be refined, and the most important features identified to simplify the diagnosis of oral epithelial dysplasia. Digital whole slide images of the figures in this paper can be found at: https://www.pathogenesis.co.uk/r/demystifying-dysplasia-histology-dataset.

A review of oral pathology in orthodontics. Part 1: Soft-tissue pathology

Orthodontists are well placed to detect soft-tissue disease of the oral cavity and associated structures because of the frequent repeat examinations of their patients. This review describes the clinical manifestations, pathologic features, and treatment of the soft-tissue pathology most likely to be encountered by the orthodontist and uncommon soft-tissue disease with significant implications for the patient. The recognition of soft-tissue disease will allow reassurance, referral, and early intervention when required.

Prevalence of Keratosis in the Oral Cavity: A Clinical Retrospective Study

INTRODUCTION

A lesion in the oral cavity can appear clinically white due to an increase in keratin (hyperkeratosis), an increase in the thickness of the spongiotic cells (acanthosis), accumulation of fluid within the epithelium, and formation of the pseudomembrane. There are several innocuous white lesions, while only a few require aggressive management. The lesions of frictional keratosis, tobacco pouch keratosis, and morsicatio buccarum (MB) are innocuous white lesions that can be treated with simple treatments. This paper aimed to study the prevalence of the three white lesions among the patients visiting Saveetha Dental College. The objectives were to study the gender prevalence of the lesions and the average age distribution of these lesions.

METHODOLOGY

The study was a retrospective clinical study that collected data from DIAS (Digital Information and Archiving Software) over four years among the patients visiting Saveetha Dental College. The inclusion and exclusion criteria were based on the clinical diagnostic features, and the existence of any other oral potentially malignant disorder made the exclusion criteria. The collected data were entered into Statistical Package for the Social Sciences (SPSS) version 26.0 (IBM Corp., Armonk, NY). The data were analyzed for descriptive and inferential statistics.

RESULTS

The total number of patients with the lesions mentioned above was 5,613, with an average age of 37.28 years. The most common lesion was frictional keratosis with 4,026 patients, followed by tobacco pouch keratosis with 1,537 patients. The least common was MB, with 54 patients. Based on gender, all of the above lesions were most commonly seen in men. The age analysis revealed that frictional keratosis and MB were seen in middle age, while tobacco pouch keratosis was seen in middle to old age.

DISCUSSION

From the above study, it is noticed that frictional keratosis was the most common lesion, which had arisen most commonly in the third molar region and was seen in the younger age group due to the eruption of the third molars. Among the lesions, the only tobacco-induced lesion was tobacco pouch keratosis, which was seen predominantly in middle to old age, implying that prolonged habit usage was essential for the lesion to develop.

CONCLUSION

This study has helped us understand the prevalence of innocuous keratotic lesions in the South Indian population. The findings of this study will give a guideline for confirming the clinical diagnosis of similar lesions. This could potentially reduce the need for undertaking a biopsy and rather try treating with less invasive modalities, and when no response is seen, then it would be worthwhile to do a biopsy.

Morphea Involving the Lips and Gingiva: A Rare Case Report

Morphea is a subtype of scleroderma that does not involve Raynaud's phenomenon or internal organ involvement. It is a connective tissue disease that features the excessive deposition of collagen in the dermis and subcutaneous tissue, leading to a thickening of the dermis and subcutaneous tissue, eventually forming a scar-like lesion. We represent a 19-year-old male Saudi patient displaying a white patch on the marginal gingiva of tooth #21 and multiple yellowish papules on the outer surface of the lip. Both teeth #21 and #22 have experienced recession and bone loss. The patient's clinical history and histopathology revealed characteristic features of localized scleroderma. A treatment was proposed involving immunosuppressants, methotrexate, and pimecrolimus cream along with topical corticosteroids and excimer laser therapy (308 nm). The patient followed the treatment plan for a full month and the white patch quickly improved for the patient. Afterward, the patient has been taking only methotrexate with a significant but gradual improvement. In this paper, we discuss the differential diagnosis to be considered and present an unusual occurrence of localized scleroderma in the oral cavity.

Comparative Analysis of Dentition and Periodontal Status in Patients With Unilateral Smokeless Tobacco Pouch Keratosis

INTRODUCTION

The consumption of smokeless tobacco (SLT) and related products has become an epidemic worldwide, especially among young people, as they come into direct contact with the tissues of the oral cavity. Therefore, the present cross-sectional study was conducted to compare the status of dentition and periodontal health of teeth associated with the unilateral SLT pouch keratosis with the unaffected contralateral side.

MATERIALS AND METHODS

In this study, 96 SLT users from north Maharashtra, India, with unilateral SLT pouch keratosis were studied. Demographic data, past and present SLT use history, features of SLT pouch keratosis, modified community periodontal index, dentition status index, and loss of tooth attachment were recorded. Data were collected and subjected to statistical analysis using the unpaired t-test and chi-square test.

RESULTS

The results of the present study showed a significant difference (p≤0.05) in gingival bleeding, pocket depth, and attachment loss in teeth associated with smokeless tobacco keratosis (STK) compared to teeth at the contralateral sides of the arch. The duration of tobacco use had a significant effect on the severity of loss of attachment at SLT pouch keratosis sides. There was a significant difference (p≤0.05) in the mean scores of the sound crown, carious crown, and coronal caries status between the SLT pouch keratosis side and the contralateral side.

CONCLUSION

The results of the study revealed that significant gingival bleeding, gingival recession, and attachment loss in the teeth are associated with SLT pouch keratosis compared with the teeth on the contralateral side without the lesion.

Oral findings in patients with cartilage-hair hypoplasia - cross-sectional observational study

BACKGROUND AND OBJECTIVES

Cartilage-hair hypoplasia (CHH) is a rare chondrodysplasia with associated primary immunodeficiency. The aim of this cross-sectional study was to examine oral health indicators in individuals with CHH.

METHODS

In total, 23 individuals with CHH, aged between 4.5 and 70 years, and 46 controls aged between 5 and 76 years were clinically examined for periodontal disease, presence of oral mucosal lesions, tooth decay, masticatory system function, and malocclusions. A chairside lateral flow immunoassay test of active-matrix metalloproteinase was obtained from all the adult participants with a permanent dentition. Laboratory signs of immunodeficiency were recorded for individuals with CHH.

RESULTS

Individuals with CHH and controls had similar prevalence of gingival bleeding on probing (median 6% vs. 4%). Oral fluid active-matrix metalloproteinase concentration was greater than 20 ng/ml in 45% of study subjects in both groups. However, deep periodontal pockets, 4 mm or deeper, were more common in individuals with CHH as compared to the controls (U = 282.5, p = 0.002). Similarly mucosal lesions were significantly more common in individuals with CHH (30% vs. 9%, OR = 0.223, 95%CI 0.057-0.867). The median sum of the number of decayed, missing due to caries, and filled teeth was nine for the individuals with CHH and four for controls. In the CHH cohort, 70% displayed an ideal sagittal occlusal relationship. Malocclusion and temporomandibular joint dysfunction prevalence were similar in both study groups.

CONCLUSIONS

Individuals with CHH have more frequently deep periodontal pockets and oral mucosal lesions than general population controls. Routine intraoral examination by a dentist at regular intervals should be recommended to all individuals with CHH.

Acute Immune-Mediated Lesions of the Oral Cavity

Although acute immune-mediated lesions of the oral cavity (AIML) can have an onset over several months, they often demonstrate rapid onset and can be self-limited. Despite the self-limiting nature of some disorders, patients with AIML can have significant pain and multisystem involvement. It is vital for the oral health care provider to arrive at the proper diagnosis with distinction from overlapping conditions, as the oral manifestations may be harbingers of more serious systemic complications.

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.

Somatic Variants and Exon-Level Copy Number Changes in Five Hyperplastic Oral Leukoplakias

Oral leukoplakia (OL), an oral potentially malignant disorder, begins with a hyperplastic/hyperkeratotic stage at which no genome-scale somatic single nucleotide variant profiles have been described so far. We performed exome sequencing of five cases at this stage with no evidence of dysplasia to identify genetic alterations (exon-level copy number alterations, indels, and single nucleotide variants), their association with transcript levels, and relationship with oral cancer susceptibility. Pathway enrichment analysis of genes associated with tobacco chewing and age-related mutation signatures, transcripts with variants predicted to be functionally damaging and those with significantly altered levels all indicated the involvement of focal adhesion, ECM-receptor interactions, regulation of cytoskeleton, and DNA repair. Two novel mutations identified in FAT1 tumor suppressor gene were associated with decreased transcript levels. In addition, 16 expressed cancer driver genes contained functionally damaging variants. Many of the affected genes were also reported in dysplastic OL lesions. The presence of variants in cancer driver genes and those shared with oral dysplasias possibly provides a basis for further progression and increased susceptibility to oral cancer.

Current understanding of frictional dermatoses: A review

Human skin is continually exposed to internal and external forces, dynamic as well as static. The skin is normally flexible and can resist mechanical trauma due to friction, pressure, vibration, suction and laceration to a considerable degree. However, an excess of these forces can abnormally affect the structure and function of the skin, setting the stage for the development of a skin disorder. Repetitive trauma can cause lichenification, hyperpigmentation, erythema, scaling, fissuring, blisters, ulceration and chronic alterations. Frictional dermatoses is an under-recognised entity with no clear-cut definition and encompasses a variety of terms such as frictional dermatitis, frictional melanosis, frictional pigmentary dermatoses and certain other named entities, many of which are confusing. The authors propose to define frictional dermatoses as 'a group of disorders caused by repetitive trauma to the skin as a result of friction of varied aetiology which can have a wide range of cutaneous manifestations depending on the type of insult.' The exact prevalence of frictional dermatoses as a separate entity is unknown. Authors who conducted this review include a group of dermatologists and post graduate students from various institutions. Literature was reviewed through PubMed, Medscape, Medline, ResearchGate and Google Scholar using the terms 'frictional dermatitis,' 'friction and skin,' 'dermatoses and culture,' 'clothing dermatitis,' 'friction melanosis,' 'PPE induced dermatoses in COVID-19 era,' etc. A total of 122 articles were reviewed and 100 articles among them were shortlisted and included in the study, after removing duplications. The review was followed up with further deliberation which resulted in the formulation of a new definition and classification of frictional dermatoses taking into account the morphology, histopathological characteristics, anatomical region affected and the major predisposing factors. The rising incidence of mechanical dermatoses in the COVID-19 era was also emphasised.

Clinical and Pathological Manifestation of the Oral Mucosa in Institutionalized Children from Romania

Institutionalized children, regardless of their age, are prone to psychiatric disorders, compared to those who live in two-parent families, due to the unfavorable physical and psychological conditions in which they develop. Unpropitious psychological conditions affect the child's general health and induce local manifestations that can be found in the oral cavity, affecting both soft tissues and teeth. Therefore, the purpose of our study was to assess and diagnose a series of pathological manifestations of the oral mucosa associated with poor living conditions or closely related to psychological stress. The clinical examination was performed by 4 specialist dentists, who consulted 150 children representing the study group and 52 children representing the control group, all having ages between 14 and 18 years old and meeting the same inclusion criteria. From the control group, 62.5% presented plaque-induced gingivitis (26.6% girls, 35.8% boys), 26.6% presented mucosal lesions produced by lip and cheek biting (23.3% girls, 35.8% boys), and 11.7% presented geographic tongue (6.6% girls, 5% boys), herpes simplex eruptions (3.3% girls, 4.2% boys) and oral ulcerations (12.5% girls, 10.8% boys). Morsicatio buccarul is a chronic, self-mutilating habit, currently becoming one of the most common tics encountered among institutionalized children. Furthermore, these children do not benefit from constant support and guidance to perform their dental hygiene, so the incidence of gingivitis induced by bacterial plaque and calculus is very high.

Oral Mucosal Lesions in Childhood

Childhood diseases are a continuous source of interest in all areas of general and dental medicine. Congenital, developmental, and hereditary diseases may either be present upon birth or appear in early childhood. Developmental anomalies, although often asymptomatic, may become grounds for different infections. Furthermore, they can indicate certain systemic disorders. Childhood age frequently brings about benign tumors and different types of traumatic lesions to the oral mucosa. Traumatic lesions can be caused by chemical, mechanical, or thermal injury. Mucocele and ranula are, by definition, traumatic injuries of the salivary glands or their ducts. Recurrent aphthous lesions are the most common type of ulcerations in childhood, and their etiology is considered multifactorial. Oral mucosal lesions in children require different treatment approaches depending on etiological factors and clinical presentation. Clinicians should have adequate knowledge of oral anatomy in order to diagnose and treat pathological conditions.

The Correlation of Swedish Snus, Nicotine Pouches and Other Tobacco Products with Oral Mucosal Health and Salivary Biomarkers

In society, tobacco products, such as e-cigarettes, and smokeless tobacco products, such as snus and nicotine pouches, are becoming more attractive. There is still a lack of information regarding the effects of these products on the oral mucosa and oral saliva biomarkers. The aim of this study is to evaluate oral mucosa and the presence of inflammatory biomarkers IL-6, IL-1, IL-8, TNF alpha and LRG-1 in saliva. Respondents were divided in four groups based on their tobacco product usage. Oral examination was carried out, saliva samples were taken, and the detection of IL-6, IL-8, IL-1, TNF alpha and LRG-1 levels in saliva was carried out. Out of the tobacco users, 30.8% were snus users, 48.7% were cigarette users and 20.5% were e-cigarette users. The control group was composed of respondents who did not use any tobacco products. E-cigarettes were used more by women, but snus was used more by men. Mucosal changes were seen in the group of snus users, and mucosal changes were only seen in men who had used 5–10 tobacco units per day for 5–10 years. Increased IL-6 levels in saliva were detected in respondents who also experienced mucosal changes. Mucosal changes were white, leathery and localized at the site where snus sachets were placed. Saliva, as an easily available biofluid, could be used as a first tool to detect potentially precancerous signs, but the LRG1 marker cannot be used as a prognostic marker.

The expression of salivary microRNAs in oral lichen planus: Searching for a prognostic biomarker

Oral lichen planus (OLP) is a premalignant disease with unknown etiology. It has been demonstrated that inflammation and immune activation play a central role in the pathogenesis of OLP. Various cellular and molecular mechanisms are involved in the pathogenesis of OLP. Studies have shown that 2-7% of OLP patients develop oral squamous cell carcinoma (OSCC). As a result, determining the prognosis of the disease will be promising in preventing oral carcinoma. MicroRNAs are involved in the regulation of cytokine expression and cytokines have a central role in the pathogenesis of OLP. As a result, their evaluation in body fluids may be helpful in assessing the disease's status and progression, and facilitating the treatment process. In this regard, much attention has been paid to the saliva of OLP patients as the sampling is cost-effective and non-invasive. Here, we discuss the potential of miRNAs in predicting the disease severity and progression.

Assessing Long Non-coding RNAs in Tobacco-associated Oral Cancer

Cancer is one of the compelling and pegged diseases battled by clinicians and researchers worldwide. Among different types of cancer, oral cancer holds the sixth position globally. With an escalating prevalence in Asian countries, India, China, and Pakistan constitute a large proportion of total incidents of oral cancer patients in terms of new cases or deaths. This mounting prevalence is ascribed to poor oral hygiene and rampant use of substances earmarked as potential risk factors for the disease. Risk factors (dietary/lifestyle habits/occupational/environmental) trigger the activation of oncogenes, dysregulation of lncRNA and miRNA, and silence the tumor suppressor genes, which robustly contributes to the onset and progression of tumorigenesis in oral squamous cell carcinoma. Evidence suggests that specific carcinogens identified in tobacco and related products alter many cellular pathways predisposing to advanced stages of oral cancer. Long non-coding RNAs represent a broad group of heterogenous transcripts longer than 200 nucleotides which do not translate to form functional proteins. They regulate various cellular pathways by specifically interacting with other RNAs, DNA, and proteins. Their role in the pathogenesis of OSCC and other cancer is still being debated. In this review, we discuss the molecular insights of significant lncRNAs involved in some crucial deregulated pathways of tobacco-associated OSCC. The implications and challenges to harnessing the potential of lncRNAs as biomarkers in early diagnosis and targeted treatment have also been analyzed.

Contact Dermatitis: Classifications and Management

Contact dermatitis (CD) is a common inflammatory skin disease caused by exposure to contact allergens and irritants. It is also the most common reason of occupational dermatitis and contributes greatly to hand dermatitis and facial dermatitis. Besides the two major forms of contact dermatitis: allergic contact dermatitis and irritant contact dermatitis, other subtypes of CD have been recognized including immediate skin reactions, photoinduced contact dermatitis, systemic contact dermatitis, and non-eczematous contact dermatitis. CD is a great imitator which can mimic many kinds of skin diseases, such as atopic dermatitis, lichen planus, and angioedema. For the diagnosis of CD, a complete medical history, including occupational history, is very important. It can give a clue of CD and provide a list of suspected substances. Besides the well-known diagnostic test, patch testing, there are many other diagnostic tests can be used to help diagnosis of CD and identify the causative allergens, including photopatch test, skin tests for detecting of immediate contact reactions, serum allergen-specific IgE test, and qualitative and quantitative testing of allergen in the suspected materials patients exposed to and challenge test. Before the treatment, the suspected irritants or allergens should be avoided completely. This includes both the removal of the patient from the environment that contains those substances and the promotion of the metabolism and expulsion of the allergens that have been absorbed by the body. In addition, it is also important to restore the skin barrier and reduce skin inflammation through multiple treatments, such as emollients, topical corticosteroids, and antihistamines, as well as systemic corticosteroids and immunosuppressants. Early and appropriate treatments are important to prevent further deterioration and persistence of the skin condition.

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.

Histopathologic Spectrum of Intraoral Irritant and Contact Hypersensitivity Reactions: A Series of 12 cases

BACKGROUND

Irritant contact stomatitis (ICS) and contact hypersensitivity stomatitis (CHS) are often caused by alcohol, flavoring agents and additives in dentifrices and foods, and contactants with high or low pH. A well-recognized contactant for ICS is Listerine™ mouthwash, while that for CHS is cinnamic aldehyde. However, many other flavoring agents and even smokeless tobacco are contactants that cause mucosal lesions that are entirely reversible. The objective of this study is to 1) present cases of ICS and CHS with a clear history of a contactant at the site and the histopathologic features of the resulting lesion and 2) define the histopathologic features that characterize such lesions.

METHODS

12 cases of ICS and CHS with known contactants that exhibited distinct histopathologic patterns were identified.

RESULTS

ICS are characterized by three patterns in increasing order of severity namely: 1) superficial desquamation, 2) superficial keratinocyte edema, and 3) keratinocyte coagulative necrosis with/out spongiosis and microabscesses. CHS is characterized by two patterns namely plasma cell stomatitis with an intense plasma cell infiltrate and a lymphohistiocytic infiltrate with or without non-necrotizing granulomatous inflammation. Three patterns of the latter are recognized: (1) lymphohistiocytic infiltrate at the interface with well-formed or loosely aggregated non-necrotizing granulomas; (2) lymphohistiocytic infiltrate at the interface with peri- and para-vascular lymphohistiocytic nodules; and (3) lymphohistiocytic infiltrate at the interface with peri- and para-vascular lymphohistiocytic nodules containing non-necrotizing granulomas. The same contactant may elicit ICS and CHS, while one histopathologic pattern may be brought on by various contactants.

CONCLUSION

ICS and CHS have distinct histologic patterns. Recognizing that these patterns are caused by contactants would help clinicians manage such mucosal lesions.

Oral lesions containing amyloid-like material

During oral pathology daily practice, true amyloid may be identified in oral amyloidosis and several odontogenic tumors. However, histologic examination often reveals other oral and perioral diseases with similar eosinophilic, acellular, amorphous substances. These include extensive areas of collagenous sclerosis, fibrin deposition, elastic fiber degeneration, and dentinoid material, which may resemble amyloid under light microscopic examination. These materials are often termed "amyloid-like" due to their close histologic resemblance to true amyloid. The rarity of most of these conditions and their strong histologic similarity may hamper an accurate diagnosis. Definitive diagnosis of these lesions may require clinical correlation; laboratory evaluation; histochemical or immunohistochemical reactions; and, in some cases, genetic investigation. In this review, we describe the main clinicopathologic features of this group of diseases that may manifest in the oral and/or perioral regions and that have in common the presence of amyloid-like material deposition.

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.

Clinical Evaluation and Anatomic Variation of the Oral Cavity

Clinicians should be knowledgeable about the anatomy of the oral cavity and variations of normal because of oral and systemic health connections. This article presents an overview of normal and variations of normal anatomy of the oral cavity.