原发肺黏液表皮样癌活检、冷冻与常规病理特征的对比分析及MAML2基因重排的意义

Comparative study of biopsy,freezing and routine pathological features of primary pulmonary mucoepidermoid carcinoma and the significance of MAML2 gene rearrangement

目的探讨原发肺黏液表皮样癌(pulmonary mucoepidermoid carcinoma,PMEC)活检、冷冻与常规病理特征及MAML2基因重排的意义。方法回顾性分析51例PMEC的活检、冷冻与常规切片的病理特征,采用FISH检测MAML2基因重排情况。结果男性38例,女性13例,男女比为2.9∶1,年龄范围8~81岁,中位年龄50岁。肿瘤最大径0.7~8.0 cm,平均3.2 cm。病理学分级:低级别26例,高级别25例。28例行活检,21例诊断为PMEC,7例诊断为其它类型的肿瘤。23例行术中冷冻病理检查,8例诊断为PMEC,15例诊断为其它类型肺恶性肿瘤。常规石蜡切片中40例(40/51,78.4%)镜下见肿瘤间质出现淋巴浆细胞浸润,形成肿瘤相关淋巴增生(tumour associated lymphoid proliferation,TALP)。MAML2基因重排总检出率为68.6%(35/51),其中低级别组检出率为84.6%(22/26),高级别组检出率为52%(13/25)。MAML2基因重排与低级别、临床分期早(Ⅰ~Ⅱ期)及有无淋巴结转移相关(P<0.05)。单因素分析显示,临床分期、病理学分级、MAML2基因重排、治疗方案均与患者总生存期延长显著相关(P<0.05)。结论TALP对PMEC的诊断具有重要提示作用,患者预后好的因素包括临床分期早、病理学分级为低级别、MAML2基因重排阳性及手术+辅助治疗/全身治疗。

Purpose To explore the pathological and clinical features of primary pulmonary mucoepidermoid carcinoma(PMEC)with formalin-fixed biopsy tissue and frozen section tissue and the significance of MAML2 gene rearrangement.Methods Tissue sections of 51 PMEC cases from routine biopsy and frozen section tissue were investigated retrospectively.Fluorescence in situ hybridization(FISH)was used to detect the rearrangement of MAML2 gene.Results There were 38 males and 13 females,with a male:female ratio of 2.9∶1.The age ranged from 8 to 81 years old,with a mean age of 50 years.The measurement of the tumors was 0.7 to 8.0 cm in greatest dimension(average 3.2 cm).Histopathological grade:26 cases were low grade,and 25 cases high grade.Among 28 biopsied cases,21 were diagnosed as PMEC,and 7 cases were other types of tumors.Among 23 cases underwent intraoperative frozen sections,8 were PMEC,and 15 were other types of lung malignant tumors.In paraffin sections,40 cases(40/51,78.4%)showed lymphoplasmacytic infiltration in the tumor stroma,forming tumor associated lymphoid proliferation(TALP).MAML2 gene rearrangement was detected in 35 of 51 cases(68.6%),including 22 low grade tumors(84.6%,22/26),and 13 high grade tumors(52%,13/25).MAML2 gene rearrangement was correlated with low-grade tumor,early clinical stage(stageⅠtoⅡ),and lymph node metastasis(P<0.05).Univariate analysis showed that clinical stage,pathological grade,MAML2 gene rearrangement,and treatment protocols were significantly correlated with overall survival(P<0.05).Conclusion TALP is an important feature in the pathological diagnosis of PMEC.Factors for good prognosis of patients include early clinical stage,low-grade histopathology,MAML2 gene rearrangement,and surgery+adjuvant therapy/systemic therapy.