Primary oral mucosal melanoma: advocate a wait-and-see policy in the clinically N0 patient

Mucosal Melanoma of the Oral Cavity: What is the Role of Elective Neck Dissection?

OBJECTIVES

Mucosal melanoma (MM) is a rare malignancy that can present in the head and neck (H&N). The Oral cavity is the second most common primary site in the H&N after sinonasal mucosa. This study investigates the impact of demographic and clinical factors on survival in oral cavity MM. Further, it investigates the outcomes and utility of elective neck dissections (END) in the management of oral MM.

METHODS

The National Cancer Database was used to evaluate 432 patients with oral cavity MM from 2004 to 2016. Kaplan-Meir and Cox regression analyses were used to determine variables associated with survival.

RESULTS

The mean age was 64.0 ± 16.0 years. Most patients were white (85.1%) and male (60.0%). Gingiva (37.6%) and hard palate (36.1%) were the most common primary subsites in the oral cavity. Five-year overall survival was 31.0%. Age (Hazards Ratio [95% Confidence Interval], 1.03 [1.01-1.06]), N-stage (1.94 [1.10-3.42]), M-stage (10.13 [3.33-30.86]), male sex (1.79 [1.06-3.03]), and African-American race (2.63 [1.14-6.11]) were significantly associated with worse survival. 199 patients (46.9%) underwent neck dissection including 118 with lymph node yield (LNY) ≥ 18. The rate of occult nodal positivity was 45.4% for LNY ≥ 18 and 28.3% for LNY ≥ 1. ENDs were not associated with improved outcomes. However, occult lymph node involvement was associated with worse overall survival (p = 0.004).

CONCLUSIONS

Oral cavity MM has a poor prognosis. Lymph node involvement, distant metastasis, age, race, and male sex are associated with worse outcomes. Performing an END did not improve survival. However, END may have a prognostic role and help select patients for treatment intensification.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:317-326, 2023.

Oral mucosal melanoma - A systematic review

Oral mucosal melanoma (OMM) is the subject of few studies, resulting in a lack of understanding. The aim of this study is to review the current literature on OMM. The term searched was "oral mucosal melanoma" between 01/01/2000 and 03/15/2021 in the PubMed Database (MEDLINE). Patients presenting with OMM and treated in our center between January 2009 and January 2020 were included in a case series. Demographics, location, risk factors, genetic mutations, treatment performed, and overall survival (OS) rates were evaluated. The PubMed database search yielded a total of 513 results, thirty-eight articles were finally included, which amounted to 2230 cases of OMM. 13 patients were included in the case series. A male-to-female ratio of 1.28:1.00 was found with a mean age at first diagnosis of 58.2 years old. Hard palate (1060 cases) and then gingiva (794 cases) were the two main locations. No risk factors could be identified. OMM were staged III or IV at diagnosis. Mutations were described as such: KIT in 14.6% of cases, BRAF in 7%, and NRAS in 5.6%. Treatment protocols varied but radical surgery was the cornerstone treatment associated with adjuvant therapies. Immunotherapy has not been evaluated for OMM. OS rates were 43.4% at 3 years, 33.1% at 5 year and 15.4% at 10 years. OMM show distinct features from cutaneous melanoma (CM): typical locations, no identified risk factors, different mutations profile, worse prognosis with advanced stage at diagnosis. Targeted therapies are still underused compared to CM.

What is the role of the surgeon in the management of head and neck mucosal melanoma in the immunotherapy era?

INTRODUCTION

The advent of immunotherapy has impacted both the management and, to a lesser extent, the outcomes for patients with head and neck mucosal melanoma. As a consequence, one might expect that the role of the surgeon would be limited to the diagnostic work-up and that systemic therapies would be the mainstay of treatment.

METHODS AND RESULTS

Here, we present the surgical aspects of the recently published United Kingdom Head and Neck Mucosal Melanoma Guideline to highlight the continued role of surgeons in the management of this disease. We highlight key areas where surgeons remain the lead clinician and reinforce the multidisciplinary requirement for exemplary patient care.

CONCLUSIONS

Despite the advent of immunotherapy, surgeons continue to have a key role to play in this disease. When indicated, it is essential that appropriate surgery is offered by a suitably experienced team.

Melanoma of the lacrimal drainage system: A systematic review

Melanoma of the lacrimal drainage system (LDSM) is a rare and subtle condition that is frequently misdiagnosed. In the present work, we conducted a systematic review investigating the clinical features, management, and prognosis of LDSM. A structured search, according to PRISMA criteria, was performed in April 2020 and updated in February 2021 on Pubmed, EMBASE, Cochrane, and SCOPUS. The articles found underwent a double-reviewer selection and the main data were extracted. After complete screening, 30 articles reporting 38 cases were included. The time from the first symptom to medical contact ranged from 1 month to 4 years. Surgery was the treatment proposed to all patients, with a variable extension of resection. LDSM is a rare disease that is burdened by poor prognosis. Early diagnosis is crucial, even if difficult to achieve. Surgery and radiotherapy are standardized treatments, while targeted therapy and immunotherapy are attractive prospects.

Primary Malignant Melanoma of Oral Mucosa - Report of Two Cases

Primary malignant melanoma of oral mucosa is a rare and aggressive tumor. It is usually seen in the 5^th and 6^th decades of life. Its mainstay of treatment is surgery. It has a very poor prognosis, which is attributed to its late detection and distant metastasis. Dentists are often the first clinicians to come across these lesions and need to be able to identify them at the earliest for a better prognosis. In this article, we present two cases of extensive primary malignant melanoma of the oral cavity. Clinically, both the cases had a similar appearance of grayish-black pigmented nodular swelling on the buccal aspect and grayish-black discoloration on the palatal aspect. There were no significant radiological changes in both cases, indicating the superficial spread of the lesion. A positron emission tomography scan was performed in the second patient, which did not show any distant metastasis. Surgery was advised as a treatment for both the patients.

Head and neck mucosal melanoma: The United Kingdom national guidelines

The United Kingdom head and neck mucosal melanoma guideline development group used an evidence-based systematic approach to make recommendations in key areas of uncertainty in the field, including accurate diagnosis and staging; the appropriate treatment pathway including surgery, adjuvant radiation and new systemic treatments, such as targeted agents and immunotherapy; and the surveillance of patients after treatment. The guidelines were sent for international peer review and have been accredited by the National Institute for Health and Care Excellence. A summary of key recommendations is presented. The full documents are available on the Melanoma Focus website (https://melanomafocus.com/activities/mucosal-guidelines/mucosal-melanoma-resources/).

Loss of nuclear BAP1 expression is associated with poor prognosis in oral mucosal melanoma

Oral mucosal melanoma (OMM) is an aggressive neoplasm with an extremely poor prognosis. BAP1 is a tumor suppressor that has been associated with the outcome of melanomas and other malignancies. In this study, we investigated the genetic alterations in BAP1 and the prognostic potential of BAP1 protein expression in oral mucosal melanoma. DNA sequence analysis of BAP1 from 12 OMM patient samples revealed missense mutations in the tissues from four patients. Based on immunohistochemical staining, loss of nuclear BAP1 expression was associated with poor overall survival (P < 0.001, Log-rank = 21.308) and distant metastasis (P = 0.034, OR = 0.320). Multivariate analysis showed BAP1 to be an independent prognostic factor (P = 0.027, HR = 0.479). It thus appears that loss of nuclear BAP1 expression is an independent prognostic factor of poor overall survival and associated with distant metastasis in OMM.

Clinical investigation of 38 cases of oral mucosal melanoma: A multicentre retrospective analysis in Japan

BACKGROUND/OBJECTIVES

The aim of the present study was to investigate treatment modalities and outcomes in oral mucosal melanoma.

METHODS

The clinical and pathological data of 38 consecutive patients with oral mucosal melanoma were retrospectively analyzed. Patients' characteristics were analyzed and overall survival (OS) rates were calculated.

RESULTS

Sixteen patients had stage III (42%), 19 IVA (50%), and three had stage IVC (8%) disease. Among the therapeutic approaches used, 31 patients (82%) received radical therapy (surgery +/- chemotherapy). The 5-year OS rate was 40%. Five-year OS rates according to the clinical stage were 71% for stage III, 24% for stage IVA, and 0% for stage IVC. Five-year OS rates according to therapeutic approaches were 52% in the radical therapy group and 0% in the palliative therapy and best supportive care groups.

CONCLUSIONS

The results of this multicentre retrospective analysis of patients with oral mucosal melanoma suggest that radical therapy based on surgical treatments with complete surgical excision with clear margins leads to a better prognosis.

A Review of the Aetiopathogenesis and Clinical and Histopathological Features of Oral Mucosal Melanoma

Oral mucosal melanoma is an uncommon, usually heavily melanin-pigmented, but occasionally amelanotic aggressive tumour with a poor prognosis. Despite radical surgery, radiotherapy, or chemotherapy, local recurrence and distant metastasis are frequent. Microscopical examination is essential for diagnosis, and routine histological staining must be supplemented by immunohistochemical studies. The aetiology is unknown, the pathogenesis is poorly understood, and the 5-year survival rate rarely exceeds 30%. In most cases, oral mucosal melanoma arises from epithelial melanocytes in the basal layer of the epithelium and less frequently from immature melanocytes arrested in the lamina propria. In both cases the melanocytes undergo malignant transformation, invade deeper tissues, and metastasize to regional lymph nodes and to distant sites. Very rarely metastasis from skin melanoma may give rise to oral mucosal melanoma that may be mistaken for primary oral mucosal melanoma. The pathogenesis of oral mucosal melanoma is complex involving multiple interactions between cytogenetic factors including dysregulation of the cKit signalling pathways, cell cycle, apoptosis, and cell-to-cell interactions on the one hand and melanin itself, melanin intermediates, and local microenvironmental agents regulating melanogenesis on the other hand. The detailed mechanisms that initiate the malignant transformation of oral melanocytes and thereafter sustain and promote the process of melanomagenesis are unknown.

Periodic acid-Schiff-positive loops and networks as a prognostic factor in oral mucosal melanoma

The prognostic factors of oral mucosal melanoma (OMM), a rare and aggressive neoplasm, remain to be determined. The aim of this study is to investigate the prognostic significance of vasculogenic mimicry in OMM. The clinical data of 62 patients with primary OMM treated in Shanghai Ninth People's Hospital from April 2007 to April 2012 were retrieved and analyzed retrospectively. Staining of periodic acid-Schiff (PAS) and CD31 immunohistochemistry were performed to evaluate the prognostic value of PAS-positive patterns, blood lakes, and microvascular density. PAS-positive loops and networks (P<0.001) as well as blood lakes (P=0.040) were found to be predictors of overall survival (OS). The presence of PAS-positive loops and networks was an independent prognostic factor of poor OS in multivariate analysis (P=0.002). Although the presence of PAS-positive loops and networks was associated with hematogenous metastasis (P=0.041) and lymphogenous metastasis (P=0.041), it was not an independent predictor of both types of metastasis in multivariate analysis. Microvascular density was not associated with OS (P=0.627) and metastasis of OMM patients. PAS-positive loops and networks have a significant prognostic value in OMM. Detection of PAS-positive patterns may lead to better staging and serve as a prognostic parameter of OMM.

Mucosal melanoma of the head and neck: a population-based study from Slovenia, 1985-2013

Objectives

To assess the incidence and to review experience with the treatment of mucosal melanoma of the head and neck (MMHN) in Slovenia between 1985 and 2013.

Methods

The National Cancer Registry database and clinical records with outcome data of identified patients treated during the period 1985–2013 in Slovenia were reviewed.

Results

In a 29-year period, 61 patients with MMHN were identified, representing 0.5 % of all head and neck malignant tumors and 42 % of all mucosal melanomas in Slovenia. 72 % originated in the sinonasal tract and were predominantly (78 %) diagnosed as a local disease. Regional metastases at diagnosis were more frequent in patients with oral/oropharyngeal primary (44 %; sinonasal MMHN 11 %, p = 0.006). Curative intent treatment was given to 48 (79 %) patients. The overall survival (OS) rates at 2 and 5 years for the whole cohort were 43 % and 18 %, respectively, and for the curative intent group 53 % and 24 %, respectively. In the latter group, multivariate analyses showed postoperative radiotherapy (PORT) to be predictive for locoregional control (LRC) (hazard ratios [HR] for surgery with PORT vs. surgery alone: 1.0 vs. 3.9, p = 0.037), whereas only the World Health Organization performance status (HR for grade 0 vs. grade 1 vs. grade >1: 1.0 (p = 0.022) vs. 1.2 (p = 0.640) vs. 7.7 (p = 0.008)) significantly influenced OS.

Conclusions

MMHN is a rare tumor with a poor prognosis. Combination of surgery and PORT offers the best prospects for LRC but without improvement of OS. Due to potential toxicity of high-dose RT such treatment is indicated in patients in whom LRC outweighs the risks of serious adverse effects.

Survival Outcomes of Mucosal Melanoma in the Head and Neck: Case Series and Review of Current Treatment Guidelines

PURPOSE

Malignant mucosal melanoma of the head and neck (MMHN) is an aggressive and rare neoplasm with poor long-term outcomes. The aim of this study is to evaluate the outcomes of patients treated by a single-institution head and neck multidisciplinary team.

MATERIALS AND METHODS

In this retrospective case series, all MMHN cases treated at the Royal Melbourne Hospital from 1990-2015 were retrospectively reviewed. Patient demographic characteristics (eg, age), treatment offered, pathology, and outcomes were collected, tabulated, and correlated with outcomes. Survival outcomes were calculated by the Kaplan-Meier method. Comparison was made between oral and sinonasal melanomas.

RESULTS

A total of 16 cases were identified. Two were excluded because of inaccessible data. Of the 14 remaining cases, 8 were sinonasal melanomas and 6 were oral cavity melanomas. Sinonasal tumor patients presented with epistaxis or visual impairment. Oral melanoma patients presented with pigmented lesions or ulceration. Follow-up ranged from 4 months to 11 years. In 2 patients, locoregional recurrences developed that were successfully re-excised. Six patients died of distant metastases despite clear surgical margins. Two patients with sinonasal melanomas died of extensive local disease with intracranial invasion. One patient died 4 years after diagnosis without disease. There were no failures in the neck. The 2- and 5-year overall survival rates were 63.3% and 31.7%, respectively, by the Kaplan-Meier method. The difference in survival between oral and sinonasal melanomas was not statistically significant.

CONCLUSIONS

Despite clear surgical margins, MMHN has a poor prognosis and most deaths are due to distant metastases. Systemic therapies such as those used in cutaneous melanoma treatment might be used in the future for MMHN.

Primary glottic malignant melanoma of the larynx (PGMML): a very rare entity

Primary glottic malignant melanoma of the larynx (PGMML) is a very rare clinical entity with less than 20 cases reported in the literature so far. The most frequently reported subsite in primary malignant melanomas of the larynx is the supraglottic larynx. The vocal cord as a subsite for primary malignant melanoma is very rare. The present case is a primary glottic malignant melanoma involving both vocal cords. PGMML may present early due to associated hoarseness of voice, unlike other non-cutaneous melanomas in the head and neck. Non-cutaneous malignant melanomas in the head and neck are historically very aggressive in nature and known for poor outcomes and survival. Most non-cutaneous melanomas described in the literature have been superficial spreading or ulcerative in nature, unlike the present case, in which proliferative, polypoidal growth was seen. No associated risk factor was present in this case. Every reported case of this rare entity further adds to the better understanding of tumour biology and expression.

Primary malignant mucosal melanoma of the upper lip: a case report and review of the literature

Background

Malignant melanoma of oral cavity is a rare condition, accounting for 0.5 % of all oral malignancies and about 1–2 % of all melanomas. Oral melanomas have extremely poor prognosis with 5 years survival rate of 12.3 %. The poor prognosis compared to cutaneous melanoma may be attributed to delay in reporting by patient and diagnosis, and apt to become ulcerated due to repeated trauma. The ‘chameleonic’ presentation of a mainly asymptomatic condition, the rarity of these lesions, the poor prognosis and the necessity of a highly specialized treatment are factors that should be seriously considered by the involved health provider.

Case presentation

We present a case of 32 years old male of Han ethnicity with mucosal melanoma of upper lip, comparing his clinical presentation and histological findings at his first visit and following the recurrence. The patient complained of black discoloration on the left side of upper lip since 4 years which gradually increased in size and later involved the skin of the lip. Excision with 5 mm safety margin was performed but the patient presented with the similar lesion after three and half years of the treatment. So, again wide excision with 2 cm safety margin was performed followed by reconstruction of the lip.

Conclusion

This case provides an example of aggressive behavior of mucosal melanoma and emphasizes on the fact that any pigmented lesion detected in the oral cavity may exhibit potential growth and should be submitted to biopsy to exclude malignancy. It also exemplifies of how the time of diagnosis and the evolution of a disease could be seriously influenced by patient’s behavior.

Primary Malignant Melanoma of the Lip: A Report of 48 Cases

PURPOSE

Lip melanoma (LM) is a rare malignant tumor and well-established treatment protocols for it are in short supply. The objective of this study was to evaluate the outcome of treatment modalities and explore the prognostic factors.

PATIENTS AND METHODS

A retrospective chart review was performed on 48 patients with primary LM treated in the authors' hospital from January 1992 to November 2013. The clinical characteristics and treatment modalities were identified and correlated with the outcomes.

RESULTS

The 5-year overall survival (OS) rate was 56.1%, and the rate of cervical lymph node (CLN) metastasis was 46% (22 of 48). A tumor of at least 4 cm (P = .001), nodular types (P = .003), and CLN (P < .0001) were independent prognostic factors for OS. Twenty-five patients died during follow-up, mainly from to neck recurrence (14 of 25). Chemotherapy significantly improved the 5-year OS rate in patients with stage IV LM (P = .03), but not in those with stage III (P = .8).

CONCLUSIONS

LM has a lower CLN and distant metastasis rate and a better prognosis than other oral mucosal melanomas. A long history of melanin pigmentation is a dangerous sign for all patients, and smoking seems to be associated with LM in male patients. Tumor size (≥4 cm), nodular type, and CLN positivity are poor prognostic factors. A wide excision with close observation is advocated as the primary treatment for stage III LM. Adjuvant chemotherapy is useful for patients with stage IV cancer, but not for those with stage III.

Prognostic factors of oral mucosal melanoma: histopathological analysis in a retrospective cohort of 82 cases

AIMS

To investigate the histopathological predictors of overall survival and metastatic failure of oral mucosal melanoma (OMM), of which the histopathological classification and microstaging has not been established.

METHODS AND RESULTS

The pathological data, including cell type (CT), level of invasion, ulceration, mitotic rate, pigmentation, necrosis, tumour-infiltrating lymphocyte (TIL) and vascular invasion, of 82 OMM patients from April 2002 to April 2012 were reviewed and analysed retrospectively. CT, ulceration, mitotic rate, pigmentation, necrosis and vascular invasion were found to be of significance in predicting the overall survival of OMM patients. CT was an independent prognostic factor of overall survival in multivariate analysis. In patients with localized OMM, CT, level of invasion, mitotic rate, pigmentation and necrosis were associated with overall survival but none of them proved to be an independent prognostic factor. CT, mitotic rate and TIL were associated with the risk of distant metastasis. TIL was revealed to be an independent factor of distant metastases risk in multivariate analysis.

CONCLUSIONS

CT was an independent prognostic factor of overall survival. Patients with epithelioid cell type OMM had a poor prognosis. Patients without TIL had a higher risk of distant metastasis.

Oral mucosal melanoma: some pathobiological considerations and an illustrative report of a case

Oral mucosal melanoma is a relatively rare malignancy with an aggressive clinico-pathological behaviour. The mean 5-year survival rate is about 15 %. It arises primarily from melanocytes found in the basal cell layer of the epithelium, but may sometimes arise from melanocytes residing in the lamina propria. The pathogenesis is complex, and few of the molecular mechanisms underlying the development of oral mucosal melanoma have been defined. The extraneous risk factors associated with oral mucosal melanoma, if any, are unknown. Oral mucosal melanomas account for about 25 % of all mucosal melanomas of the head and neck, and exhibit a profile of cytogenetic alterations, and a pathobiological behaviour and clinical course different from that of cutaneous melanomas. As they are usually painless and grow quickly, as a rule, they are diagnosed late in the course of the disease when the lesions are already large and have metastasized to regional lymph nodes. In this paper we discuss some aspects of the pathobiology of oral mucosal melanoma, and present an illustrative case report.