2000 年 5 巻 1 号 p. 65-68
We report a case of spindle cell type myoepithelioma arising from the submandibular gland initially examined by fine needle aspiration cytology (FNAC). The patient was a 47-year-old man who noticed a mass gradually enlarging in right submandibular region four years before consulting the Social Insurance Saitama Hospital. The cytological specimens revealed numerous massive clusters of spindle-shaped cells. The cells were comparatively spindle- and oval-shaped nuclei were centrally localized in them and their nuclear membrane was homogeneously hyperplasmic. Cytoplasms were slightly dense-stained with light green. Histologically, the tumor cells were uniform in spindle or elliptic shapes showing herringbone patterns. Immunohistologically, S-100, vimentin and α-SMA were positive reactions, and electron microscopically, desmosomes were indicated. In distinguishing myoepithelioma from soft tumors such as leiomyoma and neurinoma, it seems important to consider cytological findings comprehensively because they are different from each other in cell density, size and arrangement of cell populations, cell margins and cytoplasm features.
