A case of mucoepidermoid carcinoma with melanin pigmentation manifested in the palate

Abstract

This paper describes the first documented case of mucoepidermoid carcinoma (MEC) with melanin pigmentation manifested in the palate. Histopathological sections showed a neoplasm composed of epidermoid, mucous-producing and intermediate cells. Numerous large cells contained dark pigmented materials. Fontana Masson staining revealed dendritic melanocytes and melanin granules. HMB-45, Melan A and S-100 protein were all positive for melanocytes. Histopathological examination was not typical for malignant melanoma; the lesion was diagnosed as a low-grade MEC with melanin pigmentation.

Intraoral Pigmented Low-Grade Adenocarcinoma, Not Otherwise Specified: Case Report and Immunohistochemical Study

“…Pigmented salivary gland tumors are unusual. A review of English literature revealed several melanin-pigmented salivary gland tumors, including 18 Wartin's tumor [8], 5 mucoepidermoid carcinoma (MEC) [9][10][11][12][13], 2 adenoid cystic carcinoma (AdCC) [14,15] and 1 pleomorphic adenoma (PA) [16]. Melanocyte-like cells in the tumor stroma were observed in all cases, whereas some cases also presented pigment granules within tumor cells [10-12, 15, 16] (Table 1).…”

Melanin bearing myoepithelial cells in a pigmented salivary gland carcinoma: a new avatar of myoepithelial cell? A case report

“…The other cases were of mucoepidermoid tumors, where the pigment-producing cells were proved to be melanocytes [1][2][3]8]. More recently, a case of pleomorphic adenoma with melanin pigment has been described [7].…”

Pigmented mucoepidermoid carcinoma, a case report and review of the literature on melanin-pigmented salivary gland tumors

“…Only 5 tumors of salivary gland origin containing numerous melanocytes and melanin pigment in the parenchyma and/or stroma have been documented (15)(16)(17)(18)(19). Moreover, a review of the literature has yielded no convincing examples of pre-existing melanocytes in the salivary glands.…”

“…The second case was in a Caucasian who had been suffering from well-differentiated mucoepidermoid carcinoma of buccal minor salivary gland origin, reported in 1985 (16). Sekine et al (17) reported a third pigmented mucoepidermoid carcinoma of the palatal minor salivary gland origin in a Japanese patient. Clinical behavior of carcinoma is not related to existence of melanocytes; although one of the reported cases (15) was associated with lymph node metastasis, the others including the present were non-metastatic.…”

“…A review of the literature yielded only four documented cases of salivary gland tumor in which the parenchyma contained melanocytes: three cases of mucoepidermoid carcinoma (15)(16)(17), and one of pleomorphic adenoma (18).…”