Marucci Gianluca, Marchetti Claudio, Betts Christine M, Foschini Maria P
Department of Oncological Sciences, Section of Anatomic Pathology, University of Bologna, Italy.
Int J Surg Pathol. 2005 Jul;13(3):295-7. doi: 10.1177/106689690501300313.
Melanocytes are normally present in the oral mucosa, but unlike the skin, melanocytic colonization and pigmentation of nonmelanocytic tumors rarely occur. A case of pigmented mucoepidermoid carcinoma (MEC) in a 36-year-old woman is reported. On H&E-stained sections, brownish granules were seen in intermediate and epidermoid neoplastic elements and in elongated or dendritic cells showing histologic and immunohistochemical features of melanocytes. Ultrastructurally numerous epithelial cells contained large aggregates of melanin granules, a feature suggestive of phagocytosis. In addition small individual melanin granules were observed at the external border of the epithelial cell membrane. These features suggest that melanocytes colonized the MEC and that neoplastic cells may phagocytose the granules, similarly to what occurs with epidermal melanocytes. The phenomenon of melanocyte colonization of nonmelanocytic tumors should be taken into consideration in dealing with pigmented lesions of the oral cavity.
黑素细胞通常存在于口腔黏膜中，但与皮肤不同的是，非黑素细胞肿瘤的黑素细胞定植和色素沉着很少发生。本文报告了一例36岁女性色素沉着型黏液表皮样癌（MEC）。在苏木精-伊红（H&E）染色切片上，在中间型和表皮样肿瘤成分以及显示黑素细胞组织学和免疫组化特征的细长或树突状细胞中可见褐色颗粒。超微结构显示，许多上皮细胞含有大量黑色素颗粒聚集体，这一特征提示存在吞噬作用。此外，在上皮细胞膜的外缘观察到单个小的黑色素颗粒。这些特征表明黑素细胞定植于MEC，并且肿瘤细胞可能吞噬这些颗粒，这与表皮黑素细胞的情况类似。在处理口腔色素沉着病变时，应考虑非黑素细胞肿瘤的黑素细胞定植现象。
