Genetic and developmental disorders of the oral mucosa: Epidemiology; molecular mechanisms; diagnostic criteria; management

Malignant transformation of white sponge nevus: a case report of a novel keratin 4 mutation

BACKGROUND

White Sponge Nevus (WSN) is traditionally considered a benign genetic disorder affecting the oral mucosa, primarily caused by pathogenic mutations in keratin 4 (KRT4) or keratin 13 (KRT13). Despite its benign nature, recent evidence has begun to question the malignant potential of WSN.

CASE PRESENTATION

We report a case involving a 70-year-old man who presented with a white lesion on the right floor of his mouth. Initial diagnostic evaluations confirmed the lesion as WSN. Over a one-year follow-up, the lesion underwent malignant transformation, evolving into local epithelial moderate-to-severe dysplasia. Exome sequencing identified a novel insertion mutation in exon 1 of the KRT4 gene, resulting in a deletion-insertion amino acid mutation involving glycine. Single-cell RNA sequencing further revealed altered epithelial proliferation and differentiation dynamics within the lesion.

CONCLUSIONS

This case not only expands the known genetic spectrum of KRT4 mutations associated with WSN but also provides preliminary evidence suggesting the malignant potential of WSN. The novel pathogenic mutation in KRT4 is postulated to alter epithelial proliferation and differentiation, thereby raising concerns about the malignant transformation of WSN. Further studies are warranted to confirm these findings.

A novel heterozygous frameshift mutation in the KRT6A gene responsible for an uncommon phenotype of pachyonychia congenita: One case report and review of literature

Pachyonychia congenita is an uncommon autosomal dominant skin disorder characterized by hypertrophic nail dystrophy, palmoplantar keratoderma, oral leukokeratosis, and cutaneous cysts. And fissured tongue is rarely reported in patients with pachyonychia congenita. The disease is primarily associated with mutations in five keratin genes, namely KRT6A, KRT6B, KRT6C, KRT16 or KRT17. Herein we report a 9-year-old Chinese girl who has thickened nails, keratinized plaques, and fissured tongue since birth. To investigate the underlying genetic cause, whole-exome sequencing and Sanger sequencing were performed in this patient and her family members. We identified a candidate variant c.1460-2_1460del (p.S487Lfs*21) in the KRT6A gene (NM_005554.4) by whole-exome sequencing. Sanger sequencing revealed the absence of the mutation in both parents, indicating that it is a de novo variant. Thus, the novel heterozygous frameshift mutation c.1460-2_1460del (p.S487Lfs*21) within exon 9 of KRT6A was identified as the genetic cause of the patient. Our study identified a rare de novo heterozygous frameshift mutation in the KRT6A gene in a patient with pachyonychia congenita presenting fissured tongue. Our findings expand the KRT6A gene mutation spectrum of Pachyonychia congenita, and will contribute to the future genetic counseling and gene therapy for this disease.

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.

Exfoliative Cytology and Genetic Analysis for a Non-Invasive Approach to the Diagnosis of White Sponge Nevus: Case Series

BACKGROUND

White Sponge Nevus (WSN) is a rare benign disorder associated with mutations in genes coding for cytokeratin 4 (KRT4) and 13 (KRT13) characterized by dyskeratotic hyperplasia of mucous membranes. This study was aimed at examining different approaches (cytology, pathology and genetic analysis) to WSN diagnosis.

METHODS

A series of four patients with asymptomatic white diffuse oral lesions were evaluated and, before performing an incisional biopsy for pathology, an oral brush Thin Prep was collected for exfoliative liquid-based cytology (LBC). DNA for genetic analysis was also obtained from patients and both their parents, using buccal swabs.

RESULTS

Pathology and cytology showed similar results, leading to the same diagnosis of hyperkeratotic epithelium with acanthosis and spongiosis, without atypia, demonstrating the efficiency of LBC for the differential diagnosis. Sequencing analysis revealed at least 6 rare variants in the KRT4 and KRT13 genes in each patient, contributed in part by both unaffected parents.

CONCLUSIONS

Thin Prep for oral exfoliative cytology and genetic analysis are sufficient for an accurate diagnosis of WSN. The combination of cytological and genetic analyses could substitute the histologic exam, providing a non-invasive alternative for incisional biopsy.

Gingival Overgrowths Revealing PTEN Hamartoma Tumor Syndrome: Report of Novel PTEN Pathogenic Variants

PTEN hamartoma tumor syndrome (PHTS), is a spectrum of disorders caused by mutations of PTEN, in which non-cancerous growths, called hamartomas, develop in different areas of the body, often including the oral mucosa. PHTS also implies a recognized increased risk of malignancies, as PTEN is a tumor suppressor gene capable of inhibiting progression of several cancers. One of the main and most common clinical manifestation of PHTS are gingival overgrowths presenting as warty lumps. The current study describes patients with gingival or mucosal enlargements leading to the diagnosis of PHTS associated to novel PTEN pathogenic variants. Patients referred to us for gingival lumps suggestive of PHTS associated overgrowths were submitted to genetic analysis in the PTEN gene. Two related and two unrelated patients were investigated. PTEN novel pathogenic variant was found in all of them. Two patients also fulfilled diagnostic criteria of Cowden syndrome (CS). Mucocutaneous lesions, and particularly diffuse gingival overgrowths, are both early and major clinical signs revealing a potential diagnosis of PHTS. Further genetic and clinical assessments are needed in order to confirm and clarify the diagnosis within the PHTS spectrum, including, among others, the CS. A correct interpretation of oral clinical features potentially associated to PHTS is mandatory for diagnosis and a surgical approach can be useful just in case of impairment of periodontal health or for aesthetic needs. The increased risk of malignancies associated to PHTS makes a correct diagnosis pivotal to set up an appropriate lifelong surveillance, aiming at secondary cancer prevention.

Stress as worsening of the signs and symptoms of the geographic tongue during the COVID-19 pandemic: a pilot study

BACKGROUND

Geographic Tongue (GT) is a benign inflammatory disorder of unknown etiology, which is characterized by the loss of epithelium due to the atrophy of filiform papillae. It usually occurs on the dorsum of the tongue and may extend to its lateral edges. It appears as an erythematous area surrounded by whitish and slightly elevated margins. In most cases, the condition is asymptomatic, although some individuals may report symptoms that include a burning sensation of the tongue.

OBJECTIVE

Assess whether there was a change in the clinical aspect of Geographic Tongue (GT) during the COVID-19 pandemic.

METHODS

Thirty-two participants were recruited from Dentistry School Universidade Federal Fluminense. Anamnesis and oral examination were performed to collect medical history. The participants were split into two groups: control group (no GT) n = 20 and test group (with GT) n = 12. In the second step, nine participants from a 12 (75%) of the test group were contacted by phone and answered a questionnaire about changes in the signs and symptoms of GT during the pandemic. The subjects were subdivided into two groups: GT with and without signs and symptoms exacerbation.

RESULTS

In the first phase of the research, no statistical difference between control and test groups was observed regarding clinical criteria such as age (p + 0.72), gender (p = 0.24), and systemic diseases (p = 0.58). In the second phase, there was a statistical difference between GT groups with or without symptom exacerbation in terms of age and stress as a factor of the oral symptoms (p = 0.3 and 0.2), respectively. Younger patients showed a worsening of the oral lesions related to GT (p = 0.3) and reported stress during the pandemic (p = 0.02).

CONCLUSION

Younger patients were more susceptible to stress and presented more exacerbation of the oral lesions related to GT.

A Case Report on Familial White Sponge Nevus in Saudi Arabia

White sponge nevus (WSN) is an uncommon, benign, autosomal dominant disorder that usually appears at birth or in early childhood. It affects males and females equally and is caused by germ line mutations of the keratin genes leading to keratin instability and tonofilament aggregation. The condition causes painless, white, thickened, corrugated plaques to form on the oral mucosa, especially bilaterally on the buccal mucosa. Extra-orally, it occurs most often in the vaginal mucosa, as well as in the nasal and esophageal mucosa. In this report, we describe the case of a healthy 32-year-old Saudi male in Jizan in southern Saudi Arabia whose general dentist referred him to the oral medicine clinic at King Abdulaziz University Hospital, where he was diagnosed with white sponge nevus. The patient reported no medical problems and was a cigarette smoker for more than 10 years. An oral examination revealed white lesions affecting the buccal mucosa bilaterally and the labial mucosa. A biopsy of the buccal mucosa confirmed the diagnosis of white sponge nevus. Laser therapy was suggested for the aesthetic treatment of the lesions. Better awareness of this hereditary condition among dental professionals can help improve timely diagnoses early in life and thus avoid unnecessary or inadequate treatment for this benign condition.

White Sponge Nevus Caused by Keratin 4 Gene Mutation: A Case Report

White sponge nevus (WSN) is a rare autosomal dominant disease with a family history, often caused by mutations of the keratin 4 (K4) and keratin 13 (K13) genes in patients. It is characterized by frequently occurred white corrugated folds in the bilateral buccal mucosa with soft texture. On histopathological examination, hyperkeratosis of epithelial cells, edema, and vacuolar changes in the spinous cells are observed in the lesions, despite a normal layer of basal cells. WSN should be differentiated from other oral white spot diseases, mainly oral lichen planus, oral candidiasis, oral white edema, and Heck's disease, to reduce misdiagnosis and unnecessary treatment. At present, there is no specific treatment method. The purpose of this study was to report the clinical data of four WSN patients of the same family with the K4 gene mutation. The occurrence of WSN in a pair of monozygotic twins with very similar clinical presentations was identified for the first time. The gene sequencing results showed that there was a heterozygous deletion (C. 438_440delCAA) in exon 1 of the K4 gene, resulting in an aspartic acid loss in both the proband and his father. Finally, the etiology, pathogenesis, pathological manifestations, clinical manifestations, diagnosis, differential diagnosis, and related treatment methods are discussed to provide a reference for clinical treatment of the disease.

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.

Pigmented Fungiform Papillae (PFP) of the Tongue: A Systematic Review of Current Aetiopathogenesis and Pathophysiology

The pigmentation of the fungiform papillae of the tongue is a rare idiopathic condition in which only the fungiform papillae appear hyperpigmented. In the absence of any reviews on the subject, we conducted a systematic review of the aetiopathogenesis and pathophysiology of pigmented fungiform papillae (PFP) of the tongue, including its demographic and histopathological features, trying to outline a possible aetiology. The preferred reporting items for systematic reviews and meta-analyses (PRISMA) was performed using PubMed, Scopus, EMBASE databases and manual searches, for publications between January 1974 and July 2022. Inclusion criteria were case reports defining patients’ characteristics, their general medical and dental conditions, histopathological and/or immunohistochemical findings, all with a final definitive diagnosis of PFP. Overall, 51 studies comprising 69 cases of PFP which included histopathological descriptions were reviewed. Prominent features consisted of hyperpigmentation of melanocytes, melanophages, chromatophores, and a lymphocytic infiltrate in the subepidermal area of the fungiform papillae. On special staining, PFP contained melanin, not iron or hemosiderin. On immunohistochemistry, immune-reactive CD3+ T lymphocytes, S-100 and Sox10, but non-immune-reactive melan-A intraepithelial melanocytes were noted in some studies. The presence of hyperpigmented melanocytes and melanophages, with non-immune-reactive melan-A, suggests that PFP are a benign and physiological form of pigmentation. The inflammatory infiltrates described in some papillary lesions could possibly be due to traumatic events during mastication. Nevertheless, the true reasons for the hyperpigmentation of the fungiform papillae are as of yet elusive, and remain to be determined.

Clinical Oral Condition Analysis and the Influence of Highly Active Antiretroviral Therapy on Human Salivary Microbial Community Diversity in HIV-Infected/AIDS Patients

The purpose of this study was to assess the clinical oral status and investigate the effect of highly active antiretroviral therapy (HAART) on oral flora diversity in human immunodeficiency virus (HIV)-infected/acquired immune deficiency syndrome (AIDS) patients. We first recorded and analyzed the demographic indicators of 108 HIV-infected patients and assessed their periodontal health, dental health and oral lesion status by oral examination. Besides, we compared the changes in salivary microbial communities of healthy controls, before and after treatment of HAART-processed AIDS patients by Roche 454 sequencing and RT-qPCR. In HIV-infected/AIDS patients, age, sex, marital status, income level, smoking and oral health behaviors had an effect on periodontal clinical indicators; age and marital status were correlated with dental clinical indicators; most of them were accompanied by oral manifestations, mainly including candidiasis albicans, salivary gland disease, AIDS-associated periodontitis, and oral ulcers. Besides, a total of 487 species were detected in the saliva of AIDS patients. The microbial communities of HAART-unprocessed AIDS patients significantly differed from those processed patients, with 112 unique microbial species. More importantly, a large number of conditioned pathogens were also detected in the saliva samples of AIDS patients, which may be associated with opportunistic infections. Therefore, HAART might have a crucial role in salivary microecological balance in AIDS patients. And these patients should pay attention to the maintenance of oral health, and the early initiation of HAART may be important for the development of oral lesions.

Non-Plaque Induced Diffuse Gingival Overgrowth: An Overview

Non-plaque induced diffuse gingival overgrowth represents a broad class of conditions caused by several etiological factors. The aim of this review is to highlight the most recent updates and classifications of all the existent gingival overgrowths. In addition, we highlighted the diagnostic pathway that should be employed in patients affected by gingival overgrowth. Gingival overgrowth can be related to syndromic diseases including a wide spectrum of genetic and chromosomal alterations. However, thanks to scientific sharing and the availability of genetic panels it is possible to obtain an accurate phenotypic identification of well-known syndromes and also to identify new ones. This narrative review shows that through rigid, strict diagnostic protocols, the work of the clinician is greatly facilitated, despite the wide variety of pathologies considered. In conclusion, the exchange of specialists’ competencies and the multidisciplinary management of these patients, are crucial to reach diagnosis and the correct clinical-therapeutic management.

Prevalence and Characteristic of Oral Mucosa Lesions

(1) Background: Oral mucosa lesions (OMLs) are diagnosed worldwide in any population, age or gender, but in varied prevalence. OMLs can be found in each site of the oral mucosa; for some of them, it is characteristic to have a bilateral/symmetrical or unilateral/nonsymmetrical mucosal manifestation. The knowledge about its prevalence in varied populations can be useful from a clinical point of view. The aim of this study is to assess the prevalence of OMLs in patients attending outpatient dental clinic; (2) Retrospective analysis of 2747 patients’ oral cavity medical charts, who referred to oral pathology outpatient clinic. The type of diagnosed oral lesion, sex and age were evaluated. p ≤ 0.05 was considered statistically significant; (3) Results: In this study, the overall prevalence of oral mucosal lesions was found to be higher in older than younger patients. In our study, the age median was the highest in patients with xerostomia, burning mouth syndrome, angular cheilitis and oral candidiasis. The youngest median age was observed in patients with aphthae, mucocele and gingival enlargement. The higher OMLs frequency was related with the female gender. (4) It is important for clinicians to be familiar not only with distinctive features, which sometimes may not be clear, but also with linking the occurrence of OMLs with the gender and age.

Peutz-Jeghers syndrome: Skin manifestations and endocrine anomalies (Review)

Peutz-Jeghers syndrome (PJS), a rare autosomal dominant serine/threonine kinase 11 (STK11)/ liver kinase B1 (LKB1) gene-related genodermatosis, is characterized by oral hyperpigmentation (OHP); multiple gastro-intestinal mucosal benign hamartomatous polyps causing local bleeding, occlusion, intussusception, post-resection small bowel syndrome, associated increased risk of small intestinal cancer (incidence during the third decade); and 76% cumulative higher risk than the global population of developing non-gastrointestinal tumors (female predominance) including ovarian/testicular neoplasia, pancreatic and gynecologic (breast, uterus, ovarian) cancers. Suggestive PJS-associated OHP requires STK11 genetic testing. Abdominal pain in an OHP patient may be related to PJS-associated polyps. Other features include focal depigmentation followed by hyperpigmentation, and xeroderma pigmentosum-like lesions. The severity of the dermatological findings is correlated with gastrointestinal polyps. The STK11 gene is linked to reserve of primordial follicles, polycystic ovary syndrome, female fertility, and spermatogenesis. PJS is associated with 2 types of ovarian sex-cord stroma tumors (SCSTs): annular tubules (SCTATs) and pure Sertoli cell tumors. SCSTs accounts for 8% of ovarian cancer and SCTATs represents 2% of SCST, which may be associated with the overproduction of progesterone. PJS-SCTAT vs. non-PJS-SCTAT reveals bilateral/multifocal, small tumors with a benign behavior vs. a unique ovarian, large tumor with increased malignant/metastasis risk. Male precocious puberty is due to large cell calcifying Sertoli cell tumors (LCCSCTs). Notably, 30-40% of LCCSCTs are caused by PJS or Carney complex. PJS-LCCSCT is not aggressive, but it may be bilateral/multifocal, with the ultrasound hallmark being micro-calcifications. Testicular, intra-tubular large cell hyalinizing Sertoli cell tumor is the second testicle neoplasia in PJS. The skin and mucosal lesions are useful markers of PJS, assisting with the early identification of hamartomatouspolyps and initiation of serial surveillance of ovarian, or testicular neoplasia.

Distinctions in the Management, Patient Impact, and Clinical Profiles of Pachyonychia Congenita Subtypes

Introduction

Pachyonychia congenita (PC) is a rare dermatosis that confers lifelong physical and emotional morbidities in affected patients. However, the clinical findings, treatments, and psychosocial impact of this disease have not been adequately described. The International PC Research Registry (IPCRR), a multinational initiative to collect data on PC patients, has allowed an opportunity to distinguish the salient features of this disease. We aimed to characterize the breadth and extent of nail disease, treatments, and quality of life in PC patients, and to describe any significant differences in clinical presentation or treatment of PC subtypes.

Methods

The most recent IPCRR patient survey data consisting of an 857-response questionnaire and a 102-response addendum were analyzed in a retrospective analysis. The survey data were collected as part of a multinational, multicenter initiative and comprise the largest representative population of PC to date. Participants (survey respondents) were included in the study based on questionnaire responses and a genetic confirmation of having a PC subtype.

Results

A total of 857 survey responses were collected. Genetic variations among PC subtypes influence nail disease onset and severity of symptoms. Nail disease negatively impacts patients' emotional health, especially during the adolescent and young adult years. Nail treatment tools vary little in terms of effectiveness and acquired infection rates.

Conclusion and Discussion

Patients with different PC subtypes have distinct clinical nail presentations and psychosocial impact. Genetic testing should be used to confirm PC diagnoses. Further characterization of PC, especially the rarer subtypes, may allow for more individualized patient education.

Ehlers-Danlos Syndrome: Immunologic contrasts and connective tissue comparisons

Ehlers-Danlos Syndrome (EDS) is a family of multisystemic hereditary connective tissue disorders now comprised of 13 recognized subtypes, classical, classical-like, cardiac-valvular, vascular, hypermobile, arthrochlasia, dermosparaxis, kyphoscoliotic, brittle cornea syndrome, spondylodysplastic, musculocontractural, myopathic, and periodontal, as designated by the most recent 2017 International classification system. Clinical presentation of this disease can range from mild manifestations including skin hyperextensibility and joint hypermobility, to more severe complications such as vascular and organ rupture. While there may be accompanying inflammation in some of the subtypes of EDS, the pathogenic mechanisms have not been clearly defined. Thorough evaluation incorporates clinical examination, family history, laboratory testing, and imaging. In recent years, studies have identified multiple gene variants involved in the pathogenesis of specific EDS subtypes as well as elaborate clinical diagnostic criteria and classification models used to differentiate overlapping conditions. The differential diagnosis of EDS includes hypermobility spectrum disorders, Marfan syndrome, Loey-Dietz syndrome, Cutis laxa syndromes, autosomal dominant polycystic kidney disease, osteogenesis Imperfecta Type 1, fibromyalgia, depression, and chronic fatigue syndrome. Surgical treatment is reserved for complications, or emergencies involving vascular or orthopedic injury because of the risk of poor wound healing. Management techniques each have their own consequences and benefits, which will also be discussed in this review article. Patients affected by this spectrum of disorders are impacted both phenotypically and psychosocially, diminishing their quality of life.

•

There are 13 of EDS as defined by the International EDS Consortium, some with an identified genetic etiology.

•

Skin hyperextensibility, joint hypermobility, easy bruising, and organ rupture are common features of EDS.

•

Hypermobile EDS is a poorly defined entity that has been associated with MCAS and POTs.

•

The association of hEDS, MCAS and POTS has not been confirmed.

•

There is a paucity of evidence for an immunological mechanism for EDS.

Efficacy of ozonized water for the treatment of erosive oral lichen planus: a randomized controlled study

BACKGROUND

Management of erosive Oral Lichen Planus (eOLP) is challenging. Currently, topical corticosteroids are widely used as first-line therapy, but they might be associated with side-effects and incomplete clinical response. Among non-pharmacological strategies, ozone at low medical concentration has proven to induce a mild activation of protective anti-oxidant pathways, thus exerting therapeutic effects in many inflammatory diseases. The aim of this randomized controlled study was to investigate the effectiveness of ozonized water in association with conventional topical corticosteroids for the treatment of eOLP.

MATERIAL AND METHODS

Fifty-one patients were included in the study and randomized into 2 groups: study group (n=26) included patients receiving ozonized water treatment; control group (n=25) included patients receiving placebo treatment (i.e. double-distilled water). Treatment protocol consisted of 1-minute oral rinses, repeated for 4 times, twice a week for 4 weeks. All patients received conventional corticosteroid topical therapy (betamethasone soluble tablets, 2 rinses/day for 4 weeks). Assessment of size of lesions, sign and pain scores was performed before treatment, after 2 weeks of treatment (T1) and at the end of 4-week treatment (T2). Efficacy Index (EI) of treatment, candidiasis and relapse rates were also recorded.

RESULTS

All patients experienced significant improvement of sign and pain scores with a higher rate of improvement in ozone-treated group (T1 improvement rates: Thongprasom 92.2% vs 28%; VAS pain 76.9% vs 32%; p<0.05). Pain and size reduction were significantly higher in ozone-treated group both at T1 and T2 (p<0.05). Ozone-treated group showed a higher EI at every time point (T0-T2: 72.77% vs 37.66%, p<0.01). Candidiasis (32% vs 11.5%) and relapse (40% vs 34.6%) rates were higher in control group, however the differences were not statistically significant.

CONCLUSIONS

Within the limitations of this study, ozonized water seems to be effective as an adjunct therapy, in combination with topical corticosteroids, for the treatment of eOLP.

Diagnosis and treatment considerations of atypical oral pain in tuberous sclerosis

Diagnosis and management of non-specific, atypical, and non-dental pain are challenging. We hereby report a case of a 23-year-old female who presented with a complaint of intermittent dull ache over her lower front anterior teeth with no radiographic findings. She was diagnosed after history, imaging, and neurology consultation and treated conservatively with complete remission of symptoms. Proper history and counseling are mandatory for all patients. It is important to recognize patients with underlying neurological conditions and take adequate interdepartmental consultation before labeling complaints psychogenic or carrying out unwarranted dental treatment.