Huang Y, Wu C Y, Wu W, Hou L K, Zhang L P
Department of Pathology, Tongji University Affiliated Shanghai Pulmonary Hospital, Shanghai 200433, China.
Zhonghua Bing Li Xue Za Zhi. 2016 Sep 8;45(9):612-6. doi: 10.3760/cma.j.issn.0529-5807.2016.09.005.
To investigate the clinicopathological features and epidermal growth factor receptor (EGFR) gene mutation of primary pulmonary mucoepidermoid carcinoma (PMC).
Fifth-five cases of PMC were included in the study; their clinicopathological, immunohistochemical features were evaluated, and in 31 cases, paraffin embedded specimens were subjected to mutation analysis of exons 18, 19, 20 and 21 of the EGFR gene by ARMS method.
There were 32 females and 23 males. The patients' age ranged from 11 to 68 years(mean 36 years). The tumor size ranged from 0.7 to 5.5 cm(mean 2.4 cm). The tumors were located in the segmental bronchus and upper segmental bronchus. The tumors were well-demarcated, had no obvious capsules, and protruded into the bronchial lumen. Microscopically, there were three types of tumor cells including squamous cells, mucin-producing cells and intermediate cells. Fifty-three cases were low grade, two were high grade and both showed lymph node metastases. Immunohistochemically the tumor cells were uniformly negative for TTF1, Napsin A and ALK (Ventana D5F3) in all 55 cases. The tumor cells were positive for CK7, and some squamous and intermediate cells were positive for p63 and CK5/6 in all 55 cases; whereas they were positive for p40 in 53 cases. The mucin-producing cells were negative for CK5/6, p63 and p40, but were positive for PAS in all 55 cases. The Ki-67 positive rate was <10% in the low grade PMC, and was about 80%-90% in the high grade cases. Follow-up information was available in 37 patients, with no recurrence or death. There were no EGFR gene mutations in all 31 patients of PMC.
PMC is a rare malignant salivary gland-type tumor occurring mainly in the central trachea of young patients.Most PMCs are low grade with good prognosis. The rate of lymph node metastasis of high grade PMC is high. Diagnosing PMC in small biopsies could be problematic. The lack of TTF1 expression is helpful to differentiate from other primary lung cancers. There is no EGFR gene mutation in PMC.
探讨原发性肺黏液表皮样癌（PMC）的临床病理特征及表皮生长因子受体（EGFR）基因突变情况。
本研究纳入55例PMC患者；评估其临床病理及免疫组化特征，对31例患者的石蜡包埋标本采用扩增阻滞突变系统（ARMS）法进行EGFR基因第18、19、20和21外显子的突变分析。
女性32例，男性23例。患者年龄11～68岁（平均36岁）。肿瘤大小0.7～5.5 cm（平均2.4 cm）。肿瘤位于段支气管及上叶段支气管。肿瘤边界清晰，无明显包膜，向支气管腔内突出。镜下可见包括鳞状细胞、黏液分泌细胞和中间细胞三种肿瘤细胞类型。53例为低级别，2例为高级别，且均有淋巴结转移。免疫组化显示，55例患者肿瘤细胞TTF1、Napsin A和ALK（Ventana D5F3）均呈阴性。55例患者肿瘤细胞CK7均呈阳性，部分鳞状细胞和中间细胞p63和CK5/6呈阳性；53例患者p40呈阳性。黏液分泌细胞CK5/6、p63和p40呈阴性，但55例患者PAS均呈阳性。低级别PMC的Ki-67阳性率<10%，高级别病例约为80%～90%。37例患者有随访信息,均无复发或死亡。31例PMC患者均未检测到EGFR基因突变。
PMC是一种罕见的恶性唾液腺型肿瘤，主要发生于年轻患者的中央气管。多数PMC为低级别，预后良好。高级别PMC的淋巴结转移率高。小活检诊断PMC可能存在困难。TTF1表达缺失有助于与其他原发性肺癌相鉴别。PMC不存在EGFR基因突变。
