Takeda Y
Department of Oral Pathology, School of Dentistry, Iwate Medical University, Morioka, Japan.
Acta Pathol Jpn. 1992 Jul;42(7):518-22. doi: 10.1111/j.1440-1827.1992.tb03099.x.
Myoepithelial cells are a significant component of most types of salivary gland tumors. A small but increasing number of case reports have also shown that true myoepithelioma (ME) forms a distinct clinicopathologic entity of salivary gland tumors with unique histologic features, however, the malignant type of ME is exceedingly rare. The present paper reports a case of malignant ME originating from the palatal minor salivary gland. The patient was a 70-year-old Japanese male with recurrent tumor of the palatal region. Pathologically, the tumor consisted of proliferating polygonal-shaped cells and plump spindle cells with cellular atypia and frequent mitoses, forming lumen-less lobuli or strands. Clear tumor cells were also found in part. The stroma was poorly developed without any myxoid or chondroid features. Immunohistochemical study showed positive stainings for S-100 protein, actin and vimentin in the tumor cells. Ultrastructurally, tumor cells had features of myoepithelial cells.
肌上皮细胞是大多数类型涎腺肿瘤的重要组成部分。少数但数量不断增加的病例报告也显示，真性肌上皮瘤（ME）构成了具有独特组织学特征的涎腺肿瘤的一种独特临床病理实体，然而，恶性型ME极为罕见。本文报告1例起源于腭部小涎腺的恶性ME。患者为一名70岁的日本男性，腭部区域肿瘤复发。病理上，肿瘤由增生的多边形细胞和饱满的梭形细胞组成，细胞具有异型性且有频繁核分裂，形成无管腔的小叶或条索状结构。部分区域也可见透明肿瘤细胞。间质发育不良，无任何黏液样或软骨样特征。免疫组织化学研究显示肿瘤细胞S-100蛋白、肌动蛋白和波形蛋白染色阳性。超微结构上，肿瘤细胞具有肌上皮细胞的特征。
