涎腺恶性肌上皮瘤临床病理分析

Clinical and pathologic features of malignant myoepithelioma of salivary glands

目的分析涎腺原发性恶性肌上皮瘤临床表现、形态特征和生物学行为.方法对16例涎腺恶性肌上皮瘤组织进行HE染色和免疫组织化学染色,并进行回顾性分析.免疫组织化学采用EnVision法,所用抗体包括肌动蛋白、细胞角蛋白(CK)、上皮膜抗原(EMA)、波形蛋白、S-100、结蛋白、肌特异性肌动蛋白(MSA)、平滑肌肌动蛋白(SMA)、肌红蛋白,增殖细胞核抗原、白细胞共同抗原和胶质纤维酸性蛋白.结果 16例中男性6例,女性10例,年龄12～65岁,平均44岁.肿瘤主要发生于腮腺和腭部小涎腺.临床上主要表现为快速生长或生长突然加速的局部包块,可有溃疡形成、骨质破坏和神经侵犯.16例中7例为复发病例,2例有颌下或颈部淋巴结转移.大部分肿物侵犯周围涎腺组织或邻近脂肪、肌肉、骨组织,侵入程度不一.肿瘤细胞形态多样化,有透明、梭形、上皮样、浆细胞样型和混合型,有一定细胞异型性,核分裂象较多.肿瘤以透明细胞型为主,占9例.免疫组织化学示瘤细胞CK、EMA、MSA、结蛋白、S-100阳性.结论涎腺恶性肌上皮瘤为比较少见的低度恶性的肿瘤,不易发生淋巴结和远处转移但容易复发,局部软组织和骨组织易受侵犯,生物学行为不一,在组织学的基础上结合免疫组织化学等其他检查可以确诊.

Objective To analyze the clinical features, morphology and biologic behavior of primary malignant myoepithelioma (MME) of salivary glands. Methods The H&E sections of 16 MME cases were reviewed. Immunohistochemical s tudy using EnVision method for cytokeratin (CK), epithelial membrane antigen (EM A), vimentin, S-100 protein, desmin, muscle-specific actin (MSA), smooth muscl e actin (SMA), Myo, proliferation cell nuclear antigen (PCNA), leukocyte common antigen (LCA) and glial fibrillary acidic protein (GFAP) was carried out. Results Of the 16 patients studied, 6 were males and 10 were females. Their a ges ranged from 12 to 65 years (with an average age of 44 years). The tumor occu rred predominantly in the parotid gland and minor salivary gland of the palate. Common clinical features included sudden and rapid tumor growth, superficial ulc eration, bony destruction and nerve infiltration. Seven of the 16 patients devel oped local recurrences, while 2 patients had metastasis in the lymph nodes of su bmandibular or other cervical regions. Most tumors infiltrated adjacent normal s alivary gland, adipose, muscular and bony tissues. The extent of local invasion however varied. Histologically, MME showed a wide range of morphologic appearanc e, with various combinations of clear, spindle, epithelioid or plasmacytoid cell s. The tumor cells were atypical and demonstrated high mitotic activity. In this study, 9 cases were composed predominantly of clear tumor cells. Immunohistoche mically the tumor cells were positive for CK, EMA, MSA, desmin and S-100 protei n. Conclusions In general, MME is a rare and low-grade malignant salivary gland tum or. It carries a low potential for lymph node or distant metastasis but relative ly high tendency for local recurrences, resulting in destruction of adjacent sof t and bony tissues. The biologic behavior also varies, depending on the site of involvement. Morphologic diagnosis of MME can be difficult in view of the wide s pectrum of histologic changes. A definitive diagnosis however is possible with t he application of immunohistochemistry.