Melanocytic nevi of the oral mucosa – No evidence of increased risk for oral malignant melanoma: An analysis of 119 cases

A ten-year literature review of oral malignant melanoma cases: A meta-analysis study

AIM

Oral malignant melanoma (OMM) is a rare and aggressive malignant tumour arising from the proliferation of melanocytes and accounts for only 0.5 % of all oral malignancies. It is invasive and tends to metastasise. The aim of this study is to determine the patient profile of OMM and to provide information about the clinical features and treatment plans of the disease.

MATERIALS AND METHODS

The Pubmed database was searched for OMM cases published as case reports in the last 10 years. The search was limited to English and open-access case reports. A total of 49 OMMs in 45 patients from 43 case reports were analyzed. In addition to the age, gender, smoking and alcohol consumption habits of the patients, data on the signs and symptoms of OMM, location of the lesion, imaging modalities used in diagnosis and treatment, lymph node involvement, presence of metastasis, survival time, and treatment modalities were recorded.

RESULTS

In OMM cases, 18 (40 %) of the patients were female, 27 (60 %) were male, and the mean age was 53.13 ± 16.09 years. The most common symptom was "swelling" (n = 23, 33.8 %) and the most common finding was "hyperpigmentation" (n = 40, 24.4 %). The most common site of OMM was the maxilla (n = 21, 46.7 %). According to the rate of use of imaging modalities in the cases, it was determined that "advanced imaging modalities" were mostly used (n = 24, 53.3 %). It was determined that 22.2 % (n = 10) of the patients died within the first 5 years. Combined treatment (n = 21, 46.5 %) were mostly applied to the patients.

CONCLUSION

OMM is more common in the maxilla, in males and in the fifth decade of life, and advanced imaging modalities are most commonly used to detect the disease. Because of its poor prognosis, knowing the patient profile and common clinical features of OMM will increase the clinical awareness of physicians.

[About a case of primary laryngeal mucosal melanoma in a patient with medical history of oropharyngeal squamous carcinoma]

INTRODUCTION

Primary laryngeal mucosal melanoma is a rare tumour with a poor prognosis. Its often difficult diagnosis should rule out laryngeal metastatic localization of cutaneous melanoma.

CASE PRESENTATION

We report a case of primary laryngeal mucosal melanoma diagnosed in a 65-year-old man, treated 6 years previously with radio-chemotherapy and surgery for squamous cell carcinoma of the right lateral oropharyngeal region. The definitive diagnosis of primary laryngeal mucosal melanoma was made on the resection specimen, whereas the initial biopsy of the epilaryngeal mass discovered during the patient's surveillance had concluded that it was a laryngeal recurrence of the known squamous cell carcinoma.

DISCUSSION

Through this case, we propose to remind the main characteristics and the diagnostic pitfalls of these tumours.

Focal melanocytic lesions of the oral mucosa: An epidemiological and morphological study

OBJECTIVE

This study aimed to analyse the clinical and histopathological characteristics of focal oral melanocytic lesions in a Brazilian reference service in Oral and Maxillofacial Pathology.

MATERIALS AND METHODS

A cross-sectional study was conducted over an 18-year period. Demographic data and clinical features were collected from the archives, and all biopsy specimens diagnosed as oral melanocytic lesions were retrieved and reviewed.

RESULTS

We identified 339 melanocytic lesions. Of these, 191 were melanotic macules, 112 melanocytic nevi, 14 mucosal lentigo simplex, 12 melanomas, 9 solar lentigos, and 1 melanoacanthoma. Lesions occurred mostly in white-skinned (74.2%) women (65.2%). The main reported clinical aspect was the macule (67.4%), and the most affected site was the lip vermilion (25.4%), followed by the palate (22.9%). Melanomas were larger in size and were observed in older patients with an overall shorter time of onset. The most frequent subtypes of melanocytic nevi were intramucosal (44.6%), compound (24.1%), and blue nevus (20.5%). They showed a heterogeneous architectural pattern with the presence of the three cell types.

CONCLUSION

The most frequent lesions are melanotic macule and nevus, especially the intramucosal subtype. Patients are usually white-skinned women presenting a small, long-lasting, macular lesion on the lip vermilion or palate.

A Case Report of Oral Malignant Melanoma: A Silent Killer

Melanoma of the oral cavity is a rare malignant tumor that develops from a malignant melanocytic or de novo from melanocytes within the normal mucosa or skin and appears blue, black, or reddish-brown. Oral mucosal melanoma has a higher proclivity for metastasis and attacks tissue more aggressively than any other malignant tumor in the mouth. Intestinal melanoma of the head and neck is an uncommon type of cancer that should be counted among the deadliest. Malignant melanoma of the oral cavity accounts for only 0.2%-8.0% of all reported melanoma, although accounting for 1.3% of all malignancies. Because most melanotic mucosal lesions are painless at first, the diagnosis is sometimes delayed until the ulcer or growth causes symptoms. Early detection is critical for effective therapy and the only way to improve survival and prognosis in patients with oral malignant melanoma due to its poor prognosis. To avoid oral melanomas, every single colored lesion identified in the oral cavity should be treated with suspicion and adequate inquiry because a colored lesion might expand, and it should be referred for a biopsy to avoid poisoning. This article shows how the oral clinic is important in the diagnosis of oral ulcers and argues that early detection is necessary to enhance patient outcomes.

[Pigmented lesions of the mucosa]

BACKGROUND

Pigmented lesions of the mucosa are a common reason to consult a dermatologist. They have heterogeneous etiologies and comprise a wide range of differential diagnoses. Both practitioners and patients are often uncertain about the malignancy of the lesions.

MATERIALS AND METHODS

Review and demonstration of the most common pigmentation disorders of the mucous membranes, including discussion of clinical findings and underlying causes.

RESULTS

Pigmented mucosal lesions can be classified as either focal or multifocal-diffuse. Focal hyperpigmentation encompasses melanotic macules, nevi, deposition of exogenous materials or pigments, and oral melanoacanthoma. They are mostly benign but must be discerned from mucosal melanoma with an aggressive course and poor prognosis. Multifocal or diffuse hyperpigmentation may be drug-induced or indicative of an underlying medical condition. Importantly, as part of hereditary syndromes further diagnostic work-up is required.

CONCLUSION

Specific knowledge of the distribution and causes of pigmented mucosal lesions helps in clinical assessment between benign findings and those requiring further work-up and histologic clarification.

Blue Nevus of the Hard Palate: The Importance of a Careful Examination in an Emergency Setting

Oral common blue nevus is an asymptomatic, benign, rare, pigmented lesion and sometimes clinically indistinguishable from other pigmented lesions such as the cellular blue nevus or early-stage malignant melanoma. Since it shows clinical similarities with a malignant lesion and with cellular blue nevus that can itself suffer malignant transformation, the decisive diagnosis is crucial for adequate treatment, follow-up, and prognosis. Diagnosis confirmation is given by histological analysis, the reason why most oral pigmented lesions are excised. The following case presents an asymptomatic oral pigmented lesion of the hard palate discovered during observation in an emergency setting due to an abscess of dental origin. The lesion was fully excised, and histological examination reported a “common blue nevus.” In this case, we intend to present a rare lesion of the oral cavity and the importance of performing a routine oral examination when given a chance as a preventive approach.

Pigmented Oral Lesions: A Multicenter Study

Objectives  The aim of this study was to determine the prevalence and clinical features of pigmented oral lesions from Thailand.

Materials and Methods  Biopsy records of the Department of Oral Pathology, Chulalongkorn University, Department of Oral Diagnosis, KhonKaen University, Department of Oral Biology and Oral Diagnostic Sciences, Chiangmai University, Department of Stomatology, Prince of Songkla University, and Rangsit University were reviewed for oral pigmented lesions diagnosed during 1999 to 2019. Demographic data were culled from the biopsy records. Ages of the patients were subdivided into 10-year intervals. Locations of the lesions were classified as gingiva, labial/buccal mucosa, palate, floor of the mouth, tongue, as well as the combination of sites. Data were analyzed by descriptive statistics using SPSS version 20.0.

Results  Of the 47,175 accessioned cases, 241 cases (0.51%) were diagnosed in the category of pigmented oral lesions. The age of the patients ranged from 1 month to 88 years with the mean ± standard deviation = 38.74 ± 20.96 years. Regarding gender, 172 patients (71.37%) with pigmented lesions were females, while 69 patients (28.63%) were males. The female-to-male ratio was 2.49:1. The majority of the pigmented lesions were encountered at the gingiva (29.88%) followed by labial/buccal mucosa (26.97%), palate (14.94%), lip (10.79%), alveolar mucosa (9.54%), and others (7.88%), respectively. The three most common pigmented oral lesions in the present study were nevus (39.83%), followed by melanotic macule (28.63%) and amalgam tattoo (17.43%), respectively.

Conclusions  The most common pigmented oral lesion in the present study is nevus. Demographic data of the patients in the present study are in accordance with previous studies with minor differences. Even though pigmented lesions of the oral cavity constitute a small portion of the oral pathology biopsies, accurate diagnosis is important since there is an overlap in clinical appearance of benign pigmented lesions and melanoma.

Differential diagnoses of solitary and multiple pigmented lesions of the oral mucosa: Evaluation of 905 specimens submitted to histopathological examination

BACKGROUND

The aim was to analyze the frequency, clinical and demographic features of solitary and multiple/diffuse oral pigmented lesions submitted to histopathological examination, and to summarize the features that guide the clinical differential diagnosis.

METHODS

Clinical and demographic data were retrieved from biopsy records and descriptive statistics were performed.

RESULTS

Nine hundred and five (0.51%) oral pigmented lesions were retrieved among 177 356 specimens, being 95.9% solitary and 4.1% multiple/diffuse lesions. Regardless the overlapping clinical presentation, age, site, association with amalgam restoration, and a nodular appearance may help in the clinical differential diagnosis of solitary oral pigmentations. Patient's habits, site, and systemic signs and symptoms are helpful in the clinical differential diagnosis of multiple/diffuse lesions.

CONCLUSIONS

Oral pigmented lesions are a rare diagnosis in oral pathology and solitary lesions are more commonly submitted to biopsy. Some key features help in the differential diagnosis, though biopsy can be warranted in doubtful cases.

Mucosal Melanoma: Pathological Evolution, Pathway Dependency and Targeted Therapy

Mucosal melanoma (MM) is a rare melanoma subtype that originates from melanocytes within sun-protected mucous membranes. Compared with cutaneous melanoma (CM), MM has worse prognosis and lacks effective treatment options. Moreover, the endogenous or exogenous risk factors that influence mucosal melanocyte transformation, as well as the identity of MM precursor lesions, are ambiguous. Consequently, there remains a lack of molecular markers that can be used for early diagnosis, and therefore better management, of MM. In this review, we first summarize the main functions of mucosal melanocytes. Then, using oral mucosal melanoma (OMM) as a model, we discuss the distinct pathologic stages from benign mucosal melanocytes to metastatic MM, mapping the possible evolutionary trajectories that correspond to MM initiation and progression. We highlight key areas of ambiguity during the genetic evolution of MM from its benign lesions, and the resolution of which could aid in the discovery of new biomarkers for MM detection and diagnosis. We outline the key pathways that are altered in MM, including the MAPK pathway, the PI3K/AKT pathway, cell cycle regulation, telomere maintenance, and the RNA maturation process, and discuss targeted therapy strategies for MM currently in use or under investigation.

Potential association between oral mucosal nevus and melanoma: A preliminary clinicopathologic study

OBJECTIVES

To assess potential association between oral nevi (ON) and nevus-associated melanoma (NAM), in which melanoma cells coexist with nevus cells.

METHODS

A total of 74 ON patients and 7 NAM patients were retrospectively reviewed. Comparative and regression analyses of clinical and histological data were performed between two groups.

RESULTS

The mean age of the patients with ON was 36.5 years compared with that of 54.7 years of the patients with NAM (p = .008). Gender ratio was female predominance for ON (1.64:1 ratio) and male predominance for NAM (6:1 ratio). The most common location of ON and NAM was the palate (31.1%) and gingiva (71.4%), respectively. Univariate regression analysis revealed that elderly male patients (≥60 years) with junctional ON located on the gingiva correlate with higher risk of melanoma. Multivariate analysis revealed that junctional type of ON was an independent factor (adjusted OR, 38.32; 95% CI, 3.20-458.64; p = .004) associated significantly with increased risk for melanoma.

CONCLUSIONS

The preliminary study for the first time elucidated the clinicopathologic features of a Chinese series of ON and evaluated the potential association between ON and NAM with a limited sample size. Further large multicenter studies are needed to confirm the findings.

Black and Brown Oro-facial Mucocutaneous Neoplasms

Black and brown-colored mucocutaneous lesions present a differential diagnostic challenge, with malignant melanoma being the primary clinical concern. The vast majority of pigmented lesions in the head and neck region are the result of benign, reactive factors such as post-inflammatory melanosis. However, it is not uncommon to discover a range of muco-cutaneous black and brown neoplasms in the oro-facial area. The majority of black/brown pigmented neoplasms are melanocytic in origin; these are neoplasms of neural crest derivation. Melanocytic nevi are a diverse group of benign neoplasms that are the result of specific oncogenic mutations. They are common on cutaneous surfaces but can manifest in mucosal sites. Currently, nevi are classified based on clinical and histological criteria. The most common cutaneous and oral mucosal nevus is the acquired melanocytic nevus; nevi do not pose an increased risk for the development of malignant melanoma. Emerging information on specific genetic differences supports the notion of biologically distinct nevi. This article will review the classic clinical and microscopic features of nevi commonly found in the head and neck region, and discuss emerging concepts in nevus pathogenesis and taxonomy. Melanoma is a malignant melanocytic neoplasm and is a result of cumulative genetic deregulation. The etiology of malignant melanoma (MM) is multifactorial and includes underlying genetic susceptibility, UV radiation, skin-type, and race. The majority of MM occurs on cutaneous surfaces and less commonly on mucosal and extra-cutaneous visceral organs. Regardless of location, MM exhibits clinical-pathological features that relate to horizontal or vertical tumor spread. Cutaneous and mucosal MM typically present as asymmetrical, irregularly bordered, large (> 0.5 cm), heterogeneous brown-black lesions with foci of erythema, atrophy or ulceration. As with melanocytic nevi, advances in melanomagenesis research have revealed primary oncogenic BRAF and NRAS mutations associated with cutaneous MM. Unlike their cutaneous counterparts, mucosal melanomas exhibit primary oncogenic alterations in c-KIT and other genes. This article will discuss the role of specific primary oncogenic and secondary/tertiary genetic defects in differential clinical presentation, anatomic distribution, future classification changes, and targeted therapy of melanoma. The clinical and microscopic features of mucosal melanomas and a summary of management guidelines will be discussed. Additionally, this article will cover the salient features of melanocytic neuroectodermal tumor of infancy, a neoplastic entity that can involve the oro-facial region, and the clinical-pathological features of selected, commonly occurring pigmented ectodermally-derived neoplasms that are often part of the clinical differential diagnosis of black-brown pigmented lesions.

Solitary pigmented lesions in oral mucosa in Latin American children: A case series

BACKGROUND

A variety of local and systemic processes caused exogenous and endogenous pigmentation of the oral mucosa. Solitary melanotic pigmentation is rare, hence the scarce number of studies in children and adolescents.

METHODS

Clinical and histopathologic features of 10 Latin American children with solitary pigmented lesions of the oral mucosa were reviewed.

RESULTS

The area most affected was the gingiva, followed by the palate. All lesions were flat and <1 cm in diameter. A brown color was observed in oral melanocytic macules and nevi. The exogenously pigmented lesion was bluish gray. Histopathology showed that the biopsied lesions corresponded to melanotic macules, junctional nevus, blue nevus, and exogenous pigmentation.

CONCLUSION

Solitary pigmented lesions on the oral mucosa of children, from melanin pigment or exogenous pigment, may have a similar clinical presentation, but melanotic lesions such as oral melanotic macules and nevi can be differentiated from one another only with histopathologic examination.

Hyperpigmentation of the hard palate mucosa in a patient with chronic myeloid leukaemia taking imatinib

Background

Imatinib mesylate is an inhibitor of the tyrosine kinase Bcr–Abl and a first-line treatment for Philadelphia chromosome-positive chronic myeloid leukaemia (CML). Dermatological side effects include superficial oedema, pustular eruption, lichenoid reactions, erythroderma, and skin rash. Depigmentation of the skin and/or mucosa is uncommon, and hyperpigmentation is rare.

Case presentation

We present the case of a 63-year-old Caucasian male with widespread hyperpigmentation of the hard palate associated with a 9-year history of imatinib therapy to treat CML. He did not complain of any symptoms. Clinical examination did not reveal any abnormal pigmentation of the skin or other region of the oral mucosa. He did not smoke cigarettes or drink alcohol. His medication regimen was a proton pump inhibitor, a beta-blocker, cardioaspirin, atorvastatin, and imatinib 400 mg/day. Histopathologically, melanin and haemosiderin deposits were evident in the lamina propria. The lesion persisted, with no clinical change, through several follow-ups. We reviewed the literature to explore the possible relationship between oral hyperpigmentation and long-term imatinib mesylate treatment.

Conclusions

We diagnosed oral pigmentation associated with imatinib intake based on the medical history and clinical features of the pigmented macules. Oral pigmentation may have a variety of causes, and differential diagnosis requires nodal analysis. Clinicians should be aware of possible oral mucosal hyperpigmentation in patients taking imatinib mesylate. Such pigmentation is benign and no treatment is needed, but surveillance is advisable.

Is focal melanotic lesion potentially malignant? A case report

Malignant melanoma is a lesion of melanocytes that is commonly observed on cutaneous surfaces. In 35–50% of cases, it originates from a pigmented precursor. Although oral melanocytic pigmentation is very common, melanocytic malignancies such as melanoma, are rare. Oral melanoma may arise from pre-existing pigmentation, but definitive precursor lesions have not been identified. Common sites for oral melanoma are the maxillary gingiva and palate. We report a case of malignant melanoma that transformed from a long-standing, focal, pigmented lesion on the mandibular gingiva and vestibular mucosa, suggesting the potentially malignant nature of focal oral melanotic lesions.

[Pigmentations of the oral cavity]

Buccal mucosa color is explained by hemoglobin in the vessels and melanin in the epithelium. Abnormal presence of melanin pigments (hypermelaninosis, hypermelanocytosis), hematic pigments (hemoglobin, hemosiderin, iron) but also some exogenous circonstancies explain pigmented lesions (figure 1). These lesions could be localized (single lesions), multifocal (multiple lesions) or diffused. In case of a localized pigmentation with melanic appearance, melanoma must be systematically eliminated with a biopsy. In the case of a more diffused lesion, systemic disease must be evoked. A drug etiology is also possible. A blood pigment excess could be a vascular malformation (flat lesions) or a tumoral process (nodular or swollen lesions). In both cases, Kaposi's disease should be systematically eliminated. Pigmentations near dental restorations (amalgams, prosthetic crowns) could be explained by an exogenous factor but a biopsy should be performed in case of a doubt with melanoma.

Primary malignant melanoma of oral cavity: A tertiary care center experience

Background:

Primary mucosal malignant melanoma is an extremely rare, aggressive neoplasm accounting for 0.5% of all oral malignancies. Any pigmented lesion in oral cavity should have an index of suspicion, which should be investigated to detect the disease at an early stage and managed appropriately. Melanomas tend to invade locally into the tissue or metastasize more commonly than other malignant tumors of the oral cavity.

Materials and Methods:

We report a retrospective case series of eight patients suffering from primary oral malignant melanoma treated in our department between 2012 and 2014. The details were recorded from the departmental computerized database and patients on follow-up.

Results:

There were six male and two female patients with a mean age of 46.8 years. Hard palate was the most common affected site in oral cavity. Pigmented lesion\ulcer was the most common presenting symptom. Majority of patients (5 patients) were diagnosed with Stage III (distant metastasis), two patients in Stage II, and one patient in Stage I. Three patients were treated with definitive surgery and five patients with palliative chemotherapy in view of distant disease. Following surgery, two of them required adjuvant chemoradiotherapy in view of nodal spread. Patients had a mean follow-up of 10.5 months (range: 8–26 months). Patients treated with definitive surgery had a mean survival rate of 16 months (range: 10–26 months), with local recurrence in one patient. Metastatic melanoma patients treated with palliative chemotherapy had a mean disease control rate of 5 months (range 5–9 months).

Conclusion:

Oral melanoma carries dismal prognosis with a 5-year survival rate of 5–20%. Early detection of the lesion, proper evaluation, and appropriate treatment are very important to cure the disease.

Immunohistochemical expression of cyclooxygenase-2 (COX-2) in oral nevi and melanoma

BACKGROUND

Cyclooxygenase-2 (COX-2) catalyses the conversion of arachidonic acid to prostaglandin, and its overexpression has been demonstrated in different malignant tumors, including cutaneous melanoma. However, no data about the expression of this protein in oral melanocytic lesions are available to date. The aim of this study was to evaluate the immunohistochemical expression of COX-2 in oral nevi and melanomas, comparing the results with correspondent cutaneous lesions.

METHODS

COX-2 was evaluated by immunohistochemistry in 49 oral melanocytic lesions, including 36 intramucosal nevi and 13 primary oral melanomas, and in four cutaneous nevi and eight melanomas.

RESULTS

All cases of oral and cutaneous melanomas were positive for COX-2. On the other hand, all oral and cutaneous melanocytic nevi were negative.

CONCLUSION

COX-2 is highly positive in oral melanomas and negative in oral nevi and might represent a useful marker to distinguish melanocytic lesions of the oral cavity.

Spitz Nevus: A Rare Lesion of the Oral Cavity

Pigmented mucosal lesions represent a group of rare entities with different etiopathogenetic origins, histopathologic features, dermoscopic appearances, and clinical course. Solitary pigmented lesions of melanocytic origin are uncommon in the oral mucosa, and intraoral occurrence of Spitz nevus is very rare. Here we present a case of Spitz nevus occurring on the hard palate of a 26-month-old boy.

Oral Malignant Melanoma Initially Misdiagnosed as a Racial Pigmentation: A Case Report

Oral malignant melanoma (OMM) is rare, representing less than 0.5% of all oral malignancies. The most affected sites are the palate and the maxillary gingiva. Histological examination is important to establish the diagnosis of any suspicious pigmented lesion in the oral cavity, mainly if a precise clinical diagnosis is not possible. We present one case of OMM that was initially diagnosed as a racial pigmentation elsewhere 2 years earlier. Clinical examination showed multiple macules and nodules located on the hard and soft palate, gingiva and superior alveolar mucosa. These lesions were painless and presented a color variation going from dark blue to black. Histological analysis showed sheets and nests of atypical melanocytes displaying a range of shapes such as plasmacytoid, epithelioid, and round cells, located in the superficial corium extending to the deep tissues. A few tumor cells contained variable amounts of melanin. There was no invasion of blood vessels or nerve fibers. Immunohistochemical analysis revealed that the neoplastic cells were positive for HMB-45, melan-A, S-100 and negative for AE1/AE3, confirming the diagnosis of melanoma. The Ki-67 labeling index was around 25%. The patient refused any treatment and died 11 months later.

Oral Congenital Melanocytic Nevus: A Rare Case Report and Review of the Literature

Melanocytic nevi are congenital or acquired benign proliferations of cells of melanocytic origin. Oral congenital melanocytic nevi are rare, and only a few cases have been reported in the literature. The purpose of this study is to present the clinical, histological and immunohistochemical features of an oral congenital melanocytic nevus in a 16-year-old female with an 11-year follow-up and to review the pertinent literature. The reported case is the fifth well-documented case report of oral congenital melanocytic nevus in the English literature and the first with a long period of follow-up, thereby making it an important contribution to the knowledge regarding this uncommon oral mucosa lesion.

Oral melanocytic nevi: a clinicopathologic study of 100 cases

OBJECTIVE

The purpose of this study was to evaluate the clinical and histopathologic features of oral melanocytic nevi (OMN).

STUDY DESIGN

One hundred cases of OMN were retrieved from the files of two oral pathology services, and the data were analyzed with regard to histologic type and clinical features.

RESULTS

Intramucosal nevus was the most common type (61%), followed by common blue nevus (23%), compound nevus (7%), and junctional nevus (3%). Combined nevus and cellular blue nevus were rare (2% each). The hard palate was the most commonly affected site (33%), followed by the buccal mucosa (18%), vermilion border of the lip (18%), and gingiva (15%). An interesting case of intramucosal nevus with lipomatosus-like changes and neurotization and two cases of oral dysplastic nevus are also reported.

CONCLUSIONS

Intramucosal and common blue nevi are the most common types of OMN. Dysplastic nevus, which is recognized as a marker for melanoma in the skin, can rarely involve the oral cavity. Accordingly, dentists, especially oral and maxillofacial pathologists, should become familiar with the clinical and histopathologic features of this entity.

Intramucosal nevus in the oral cavity

AIM

The aim of this study is to report a clinical case of oral nevus.

BACKGROUND

Nevus is a congenital or acquired benign neoplasia that can be observed in the skin or mucous membranes. It is an uncommon condition in the oral mucosa. When it does occur, the preferred location is on the palate, followed by the cheek mucosa, lip and tongue.

CASE REPORT

In this case study, we relate the diagnosis and treatment of a 23-year-old female patient with an irregular, pigmented lesion of the oral mucosa that underwent excisional biopsy resulting in a diagnosis of intramucosal nevus.

CONCLUSION

Nevus can appear in the oral mucosa and should be removed.

CLINICAL SIGNIFICANCE

It is important for dental professionals to adequately categorize and treat pigmented lesions in the mouth.

Melanoma of the oral cavity: pathogenesis, dermoscopy, clinical features, staging and management

Primary mucosal melanoma of the oral cavity is an exceedingly rare neoplasm which is estimated to comprise 1-2% of all oral malignancies. In contrast to cutaneous melanomas, the risk factors and pathogenesis are poorly understood. The predominate localization of primary oral melanoma is hard palate and maxillary alveolus. Dermoscopy may be utilized as an adjunctive tool in the clinical differential diagnosis of oral mucosal melanoma whenever the lesion is accessible with a dermoscope. Surgery is the mainstay of treatment, but it may be challenging depending on the location of the tumor within the oral cavity and its size. Adjuvant therapy with dacarbazine, platinum analogs, nitrosoureas and interleukin-2 have been utilized with low response rates. Imatinib may be effective for patients with with c-Kit gene mutations. Sunitinib and dasatinib have been reported effective in selected cases. Vemurafenib and dabrafenib are targeted agents for patients with BRAF mutation-positive melanoma. Ipilimumab, an anti-cytotoxic T-lymphocyte antigen 4 antibody and pembrolizumab, a monoclonal antibody targeting programmed death 1 receptor may be a feasible treatment option in patients with metastatic mucosal melanoma.

Pediatric soft tissue oral lesions

This article provides an overview of common color changes and soft tissue oral nodular abnormalities in children and adolescents. The clinical presentation and treatment options to address these conditions are presented in a concise approach, highlighting key features relevant to the oral health care professional.

Intramucosal nevus of buccal mucosa in a male child

Nevus (mole or birthmark) is a benign tumour of skin and mucosa characterised by the presence of melanin-producing, neuroectodermally derived cells, which can be light to dark brown, reddish brown, blue or flesh coloured. It varies in shape from oval to round. Oral melanotic nevi are uncommon oral lesions causing focal pigmentation. They were found only in 0.1% of population in a large survey. Nevi can be acquired over time or congenital. Acquired nevi are considered benign neoplasms whereas congenital nevi are hamartomas. They are located usually on the palate but less commonly on buccal mucosa, gingiva and lips. This article presents a case report of an intramucosal nevus of buccal mucosa in a 5-year-old boy with its surgical removal.

BRAF and GNAQ mutations in melanocytic tumors of the oral cavity

OBJECTIVE

The genetic factors participating in oral melanoma evolution have not been studied extensively. We aimed to analyze the prevalence of BRAF and GNAQ mutations in a series of oral melanocytic tumors, nevi, and melanomas.

STUDY DESIGN

The study group consisted of 4 melanomas and 10 nevi (6 intramucosal, 4 blue nevi). DNA was extracted from paraffin-embedded tissue sections, and mutations in GNAQ and BRAF were analyzed with the use of mass spectrometery.

RESULTS

V600E point mutation was identified in the BRAF gene in 3 intramucosal nevi and in 2 melanomas. Only 1 blue nevus harbored the GNAQ209 mutation. None of the BRAF-positive samples harbored GNAQ mutations.

CONCLUSIONS

The finding of BRAF mutations in oral benign and malignant melanocytic lesions points to a potential initiating role of BRAF in malignant transformation, which may have important therapeutic implications as those with BRAF mutations may benefit from specific treatment using RAF inhibitors.

Malignant melanoma of the oral cavity. Review of the literature and experience in a Peruvian Population

OBJECTIVE

To determine the epidemiological profile of malignant melanoma cases treated at the National Institute for Neoplastic Diseases "Dr. Eduardo Caceres Graziani" (INEN) over the period 1952 to 2008.

STUDY DESIGN

All clinical records with complete data of patients presenting a histopathological diagnosis of malignant melanoma of the oral cavity were reviewed. Data such as age, gender, location, tumor size, disease length, presence of metastasis, treatment received and year of admission were recorded.

RESULTS

During the study period 97 cases were found. The average age of patients was 52.85±1.6 years old mostly between 50 and 59 years old; the predominant gender was the female. The most common location was the palate and there was 58.8% of cases with a tumor size bigger than or equal to 4 cm. The length of the disease in 38.1% of the cases was longer than a year and in great part of the cases (69.1%) there was no metastasis. The treatment of choice was the surgery plus radiotherapy in 38.1% of the cases. According to the admission date it was also noted that the number of cases is increasing.

CONCLUSION

The results of this study demonstrate a late diagnosis and an increasing frequency of this neoplasia in the oral cavity.

Extensive intraoral blue nevus--case report

Nevus is a congenital pigmented malformation rarely found in the oral mucosa. Around one third of cases located in this anatomical region are of the blue type, a histological variant with considerable tendency to malignancy. This study reports the case of a male patient, chronic smoker, with a blue nevus measuring 5 cm in diameter on the hard palate. Since controversy exists in the literature regarding the incisional biopsy of pigmented lesions with malignant or malignant potential, excision without previous biopsy of the lesion was the therapy of choice for this case. The patient was followed-up for two years with no sign of recurrence or malignant transformation.

Oral melanotic macule and primary oral malignant melanoma: epidemiology, location involved, and clinical implications

BACKGROUND

Oral malignant melanoma must be differentiated from melanotic macule.

STUDY DESIGN

Retrospective review of 2 series of oral melanotic macule (n = 52) and oral melanoma (n = 130) were conducted to investigate the epidemiology and location involved and assess their differences.

RESULTS

The mean age of oral melanotic macule patients was 47.3 years, with female:male ratio 2.1 and the lower lip being the predominant location. The mean age of oral melanoma patients was 53.8 years, with no observed sex predilection and the main locations being palate and gingiva. Differences between the 2 cohorts in age (P = .006), gender (P = .014), and lesion site (P < .001) were noted. In this review, 1 case of oral melanotic macule was found to subsequently develop into melanoma.

CONCLUSIONS

Oral melanotic macule may possess malignant potential. Biopsy is recommended to differentiate oral melanoma from melanotic macule for male patients >60 years old with suspected melanotic macule lesion located on the palate.

Expression of fatty acid synthase (FASN) in oral nevi and melanoma

OBJECTIVE

The aim of this study was to determine the expression of fatty acid synthase (FASN) in oral nevi and melanomas, comparing the results with correspondent cutaneous lesions.

MATERIALS AND METHODS

Expression of FASN was evaluated by immunohistochemistry in 51 oral melanocytic lesions, including 38 intramucosal nevi and 13 primary oral melanomas, in 10 cutaneous nevi and in 14 melanomas.

RESULTS

Fatty acid synthase was strongly expressed only in melanomas, either of the oral mucosa or cutaneous. On the other hand, most oral and cutaneous nevi were negative, with a few oral cases showing focal and weak expression.

CONCLUSION

Fatty acid synthase is expressed in malignant melanocytes, and it can be a helpful marker to distinguish oral melanomas from oral melanocytic nevi.

Melanin-associated pigmented lesions of the oral mucosa: presentation, differential diagnosis, and treatment

Intraoral pigmentation is quite common and has numerous etiologies, ranging from exogenous to physiological to neoplastic. Many pigmented lesions of the oral cavity are associated with melanin pigment. The differential diagnosis of mucosal pigmented lesions includes hematomas, varices, and petechiae which may appear to be pigmented. Unlike cutaneous melanomas, oral melanomas are diagnosed late and have a poor prognosis regardless of depth of invasion. As such, the clinical presentation and treatment of intraoral melanoma will be discussed. Developing a differential diagnosis is imperative for a clinician faced with these lesions in order to appropriately treat the patient. This article will focus on the most common oral melanocytic lesions, along with mimics.

A malignant melanoma associated with a blue nevus of the lip

Blue nevi are characterized by a collection of pigment-producing melanocytes in the dermis. These lesions clinically present as well demarcated cerulean-blue or bluish black colored papules or plaques that usually measure less than 1 cm in diameter. They are typically found on the dorsal surface of the hands and feet or in the head and neck region; however, they are rarely found in the oral cavity. These lesions are usually benign and stable over time. However, malignant melanomas developing in or associated with a blue nevus (which is also called malignant blue nevus) have been only rarely reported. A malignant blue nevus might develop in a common blue or cellular blue nevus, a giant congenital nevus or in a nevus of Ota, or it may be malignant from the start. Malignant blue nevi most commonly are found on the scalp. A malignant blue nevus of the lip has not been previously reported in the medical literature. We report here on a patient with a malignant melanoma associated with a blue nevus of the lip. The malignant melanoma was presumed to have developed from a blue nevus that was present on the upper lip of a 50-year-old male.

Pigmented lesions of the oral mucosa and perioral tissues: a flow-chart for the diagnosis and some recommendations for the management

The term "pigmentation of the oral mucosa" is applied to a wide range of lesions or conditions featuring a change of color of oral tissues. Lesions not associated with an accumulation of pigment (e.g., Fordyce spots) are usually not classified as pigmented lesions. Two groups of pigmented lesions of the oral mucosa are recognized: 1) melanin-associated lesions, including racial pigmentations, melanotic macules, melanocytic nevi, and malignant melanoma; and 2) nonmelanin-associated lesions (e.g., blood-related pigmentations, metallic pigmentations). This paper presents a clinicopathologic review of the recent literature with emphasis on the main diagnostic features, including the use of immunohistochemical markers. A flow-chart is added that may help the clinician in the diagnosis and management of these lesions.