Update on primary head and neck mucosal melanoma

Abstract

Primary mucosal melanomas (PMMs) of the head and neck are uncommon malignancies that arise mainly in the nasal cavity and paranasal sinuses, followed by the oral cavity. The mainstay of treatment is radical surgical resection followed by adjuvant radiotherapy in selected patients with high-risk features. Multimodality therapy has not been well studied and is not standardized. Adjuvant radiotherapy seems to improve locoregional control but does not improve overall survival (OS). Elective neck dissection is advocated in patients with oral PMM. Systemic therapy should be considered only for patients with metastatic or unresectable locoregional disease. Despite improvements in the field of surgery, radiotherapy, and systemic therapy, patients with PMM still face a very unfavorable prognosis (5-year disease-free survival [DFS] <20%) with high rates of locoregional recurrence and distant metastasis. The present review aims to summarize the current state of knowledge on the molecular biology, pathological diagnosis, and management of this disease.

Melanoma of the Oral Cavity: an Analysis of 46 New Cases with Emphasis on Clinical and Histopathologic Characteristics

“…We found that two of our primary cases in which S-100 was run were negative (90 % positivity). This statistic is similar to the 91 % immunoreactivity of mucosal melanomas found in a review of 115 cases by Thompson et al, reinforcing the need to run a panel of immunohistochemical stains [19,20]. One hundred percent of our primary cases in which Melan-A was performed were positive, and 95.5 % of our cases in which HMB-45 was run were positive.…”

“…We noted 1 of our 32 primary cases to be melanoma in situ, which is infrequent; eighty-five percent of oral melanomas are invasive or have an invasive and in situ arrangement [4]. One case of pseudoalveolar pattern, described by previous authors [18,19], also is noted in our series. Tariq et al [18] describe this pattern as ''tumor cells lining fibrous septae along with formation of clear space due to loss of cohesiveness of tumor cells in the center'' (Fig.…”

“…Lopez et al [19] proposed looking for atypical melanocytes or junctional activity within the epithelium adjacent to the lesion (with or without pagetoid spread) to help differentiate between primary and metastatic tumors, however, the diagnostic challenge still exists when the surface is ulcerated, as was the case in several of our specimens. Therefore, a thorough medical history, physical examination, and further diagnostic tests, including examination of skin and lungs, liver function, and brain and bone scans, are imperative in ruling out a metastatic lesion [7].…”

“…Variable expression of S-100 protein, MART-1/melan-A, MITF, tyrosinase, and HMB-45 is present in oral melanoma specimens. S-100 protein and tyrosinase tend to be more sensitive markers, and HMB-45 may show more specificity [19]; however, not one single marker is 100 % sensitive. We found that two of our primary cases in which S-100 was run were negative (90 % positivity).…”

“…By the time the tumor is diagnosed, the malignant cells often have invaded to a deeper level and are thus at a higher stage than the average cutaneous melanoma [6,9,22]. The 5-year survival rate varies between 15 and 20 % [4,6,23], with older age, extent of the primary tumor, poor accessibility for resection, and non-pigmented lesions contributing to a poorer outcome [19,24]. Lymph node involvement tends to have a direct negative effect on prognosis in mucosal melanomas [24].…”