De Cecio R, Cantile M, Fulciniti F, Botti G, Foschini M P, Losito N S
SC Anatomia Patologica e Citopatologia, Istituto Nazionale Tumori Fondazione "G. Pascale", Napoli, Italy.
Istituto Cantonale di Patologia, Servizio di Citologia Clinica, Locarno, Switzerland.
Pathologica. 2017 Mar;109(1):1-8.
Epithelial-myoepithelial carcinoma (EMC) is a rare biphasic tumor accounting for less than 2% of all salivary gland malignancies. It presents as a slowly growing, asymptomatic small size mass, with ulceration of overlying mucosa in some cases. Microscopically, it is characterized by glands lined by the simultaneous presence of two different cell components, inner epithelial cells and outer myoepithelial cells. Immunohistochemical staining of myoepithelial cells is variably positive for vimentin, Smooth Muscle Actin (SMA), Muscle Specific Actin (MSA), S100, Smooth Muscle Myosin Heavy Chain I(SM-MHC), calponin and p63. Several molecular alterations, mainly point mutations, have been described. Mutations of HRAS, AKT1, CTNNB1 and PIK3CA were highlighted in variable percentage of EMC samples. EMC is considered a low-grade malignant tumor with a 5-year survival rate of 94% that may commonly recur locally after resection in 30-50% of cases. At the moment, adequate resection with negative margins is the minimum recommended and necessary treatment.
上皮-肌上皮癌（EMC）是一种罕见的双相肿瘤，占所有涎腺恶性肿瘤的比例不到2%。它表现为生长缓慢、无症状的小肿块，某些情况下覆盖黏膜会发生溃疡。在显微镜下，其特征是腺体由两种不同的细胞成分同时排列而成，即内层的上皮细胞和外层的肌上皮细胞。肌上皮细胞的免疫组织化学染色对波形蛋白、平滑肌肌动蛋白（SMA）、肌肉特异性肌动蛋白（MSA）、S100、平滑肌肌球蛋白重链I（SM-MHC）、钙调蛋白和p63呈不同程度的阳性。已经描述了几种分子改变，主要是点突变。在不同比例的EMC样本中突出显示了HRAS、AKT1、CTNNB1和PIK3CA的突变。EMC被认为是一种低级别恶性肿瘤，5年生存率为94%，30%-50%的病例在切除后可能会局部复发。目前，切缘阴性的充分切除是推荐的最低必要治疗方法。
