泪腺腺样囊性癌中MYB蛋白表达及分子遗传学特征分析

MYB protein expression and molecular genetic characteristics in lacrimal adenoid cystic carcinoma

目的探讨泪腺腺样囊性癌(adenoid cystic carcinoma,ACC)中MYB蛋白表达及分子遗传学特征。方法收集16例泪腺ACC、20例泪腺非ACC,采用免疫组化EnVision法和FISH检测泪腺ACC中MYB蛋白表达和MYB基因易位,分析泪腺ACC病理及分子遗传学特征,并复习相关文献。结果16例泪腺ACC患者年龄为19~74岁,平均49岁,男女比为5∶11,肿瘤最大径0.8~4.5 cm,平均2.6 cm。肿瘤组织主要由导管细胞和肌上皮细胞构成,形成管状、筛状和实性结构,筛孔内可见嗜碱性黏液样物质,并可见神经侵犯。病理学分级Ⅰ级5例,以管状或筛状结构为主,无实性成分;Ⅱ级9例,管状、筛状和实性成分均有,且实性成分≤30%;Ⅲ级2例,管状、筛状和实性成分均有,且实性成分>30%。免疫组化法检测MYB蛋白的阳性率为100%(16/16),其中强阳性5例,中等阳性11例。FISH检测MYB基因易位的阳性率为87.5%(14/16),其中2例FISH检测阴性者免疫组化均为中等阳性。结论泪腺ACC易在眼部局部复发或远处转移,MYB蛋白在泪腺ACC中具有较高的阳性率,免疫组化及FISH检测MYB有助于泪腺ACC与其他疾病进行鉴别。

Purpose To investigate the expression and molecular genetic characteristics of MYB in adenoid cystic carcinoma(ACC).Methods Sixteen cases of lacrimal ACC were collected and 20 cases of lacrimal non-ACC tumors as controls.Immunohistochemistry of EnVision method and fluorescence in situ hybridization(FISH)were used to detect MYB protein expression and MYB gene translocation in lacrimal ACC.At the same time,the pathological and genetic characteristics of lacrimal ACC were analyzed with review of literature.Results The 16 patients with ACC were 19 to 74 years old,with the average age of 49 years.The male to female ratio was 5∶11.The tumor’s largest diameter was 0.8 to 4.5 cm,with an average of 2.6 cm.The tumor tissue was mainly composed of ductal cells and myoepithelial cells,forming a tube,which was the sieve-like and solid structure with basophilic mucus-like substance and nerve invasion.According to the pathological classification,5 cases were grade I which consisted of mainly tubular or cribriform structure,without solid components.9 cases were grade II which had tubular,sieve structures and solid components(≤30%).2 cases were gradeⅢ,which had tubular,sieve structures and solid component(>30%).The positive expression rate of MYB protein was 100%(16/16)which was detected by immunohistochemistry.It was shown that 5 cases were strongly positive and 11 cases were moderately positive.The positive rate of MYB gene translocation detected by FISH was 87.5%(14/16),in while 2 cases with negative FISH test showed moderately positive expression by immunohistochemistry.Conclusion Lacrimal ACC is prone to local recurrence or distant metastasis in the eye.MYB protein has a high expression rate in the lacrimal ACC.The detection of MYB by immunohistochemistry and FISH is helpful to make the differential diagnosis between lacrimal ACC and other diseases.