内淋巴囊瘤的临床和VHL基因突变分析研究

Clinical and VHL gene mutation analysis of endolymphatic sac tumor(ELST)

目的观察内淋巴囊瘤的临床特点、影像学和听力学特征,探讨内淋巴囊瘤的VHL基因突变情况。方法经术后病理确诊、经过我院手术治疗的内淋巴囊瘤病人共4例(2男2女),中位年龄为40.5岁(15～62岁),整理该病例系列临床基本资料,以及影像学和听力学检查结果,进行VHL基因突变检测,术后随访6～35个月。结果三例患者中首发症状1例为患侧面瘫,3例为患侧单侧耳鸣,听力测试提示感音神经性听力下降。颞骨CT表现为内淋巴囊区类圆形膨胀性骨质破坏,局部呈虫蚀样。内耳MR表现为内淋巴囊区混杂T1长T2信号影,边缘呈分叶状,部分其内见液-液平面,病灶不均匀明显强化。病例3还发现肾脏下极占位(病理:肾透明细胞癌),结合内淋巴囊瘤,以及发现VHL第3外显子发生杂合缺失c.620_633del,导致p.Ala207GlyfsX44,最终确诊为von Hipple-Lindau(VHL)病,并给予遗传咨询。结论对临床上单侧耳鸣、听力下降的患者需考虑到内淋巴囊瘤的可能,它独立发生,或合并其他中枢神经系统或内脏病变,是VHL病的一个表现,需要进一步进行VHL基因突变检测和遗传咨询。

Objective To explore the clinical characteristics of endolymphatic sac tumor(ELST),as well as its presentation in CT scanning,MR imaging and hearing test.To analyze the VHL gene mutation in ELST and its related entities.Methods The ELST case series comprised of 4 cases(2 male and 2 female).The median age was 40.5 years(15~62 years).The post-operative follow-up was 11~35 months.Results The primary cause of visit was unilateral tinnitus in 3 cases.The other case was first presented with facial paresis.The hearing test indicated sensorineural hearing loss in the affected ear.Temporal bone CT scanning showed erosion of the bone structure in the endolymphatic sac area with unsmooth margin.In MR imaging,mixed signal intensity on T1 weighted sequence and long signal intensity on T2 were found in the endolymphatic sac area.It showed a lobulated appearance with some fluid-fluid level.The ELST showed inhomogeneous enhancement in MR imaging.In Case 3 the space-occupying lesion in kidney was identified by pathological examination to be renal clear cell carcinoma(RCC).Taken RCC and ELST together,in addition to VHL gene mutation(c.620_633del)in exon 3 leading to p.Ala207GlyfsX44,the diagnosis for Case 3 was von Hippel-Lindau(VHL)disease.Genetic consultation was performed accordingly.Conclusion ELST should be considered when the chief complaint is just unilateral tinnitus and hearing loss.It can occur alone or as a manifestation with other disorders in central neural system or viscera in VHL disease.Further genetic testing on VHL mutation is recommended.