Desmoplastic melanoma of the oral cavity: diagnostic pitfalls and clinical characteristics

Abstract

ObjectivesDesmoplastic melanoma of the oral cavity is an extremely rare condition that is often confused on initial diagnosis with non-melanotic benign lesion or spindle cell tumors. The purpose of this article was to raise awareness of the disease using a literature review.Materials and MethodsWe analyzed 19 desmoplastic melanoma cases reported in the literature and added our experience. Data on clinical, histopathology, treatment, and survival were retrieved and analyzed. Survival analysis was by the Kaplan-Meier method.ResultsInitial clinical and histopathological features were indistinctive, and a definite diagnosis of desmoplastic melanoma at initial assessment was possible in only 23.5% of cases. Among tests, immunohistochemical studies for S-100 and vimentin were all positive. The 5-year disease-free survival rate for oral desmoplastic melanoma was 0%, and the 5-year overall survival rate was 55.0%.ConclusionOral desmoplastic melanoma has a high percentage of initial misdiagnosis and propensity for local recurrence. Thus, careful initial diagnosis and adequate surgery may result in improved overall survival.

Expression of S100, HMB45 and Melan A in Oral Mucosal Melanoma

“…HMB45 staining was not observed with any of the desmoplastic variants while only one out of five was stained with Melan A [1]. A similar finding was observed by Seung Ki Min who treated 12 oral melanoma tissue samples with S100 and HMB45 and found that S100 was positive with all 12 cases while HMB45 failed to stain 7 out of 12 cases [8]. The role of S100 in the diagnosis of this rare variant is extremely encouraging where HMB45 fails [9].…”

“…Although the sensitivity of this marker is low, the very fact that this antibody does not appear to react with any nonmelanocytic tissues suggests a good specificity for this marker [10]. Among the studies included in our review, a study done by Chuan-Hang Yu suggested HMB45 to be a less sensitive marker than S100 but the staining intensity of HMB45 to be higher than that of S100 and Melan A [2,[8][9][10][11][12][13]. The role of S100 in diagnosing metastatic melanomas was suggested to be more significant than that of HMB45 and Melan A [2].…”

“…Although these markers have been used frequently and extensively for the diagnosis of cutaneous melanomas, the use of these markers in melanomas of oral mucosa is relatively new and infrequent. Oral mucosal melanomas differ from cutaneous melanomas with respect to incidence, clinical features and growth patterns [3][4][5][6][7][8][9][10]. Hence the study of these markers in melanomas of the oral cavity deserve special attention.…”

Treatment Modalities of Recurrent Oral Mucosal Melanoma In Situ

“…López et al reported on a bad prognosis of primary mucosal melanoma with 5-year disease-free survival rates of less than 20% [ 14 ]. With a special focus on desmoplastic melanoma of the oral cavity, poor 5-year disease-free and overall survival rates (0%, 55%) were reported [ 15 ]. A review reported recurrences in 11.6% and mortality in 54.8% of cases of primary oral melanoma [ 16 ].…”