鼻腔鼻窦淋巴上皮癌的影像表现及与嗅神经母细胞瘤功能MRI参数的比较

Imaging characteristic features of sinonasal lymphoepithelial carcinoma and comparison with functional MRI parameters of olfactory neuroblastoma

目的探讨鼻腔鼻窦淋巴上皮癌(LEC)的CT和MRI特征性影像学表现,并与嗅神经母细胞瘤(ONB)的动态增强和扩散加权成像(DWI)参数比较。方法回顾性分析2014年2月至2019年11月于首都医科大学附属北京同仁医院经病理证实的7例鼻腔鼻窦LEC患者的临床和影像学资料,男5例,女2例,年龄35~58(45±9)岁。观察其CT和MRI表现,测量MRI动态增强参数和表观扩散系数(ADC)值。收集同期18例ONB患者影像资料。采用独立样本t检验或校正t检验、Fisher确切概率法比较LEC和ONB患者间各参数差异。结果6例LEC肿瘤起源于鼻腔筛窦区,1例起源于鼻眶区,其中位于左侧6例,双侧1例。7例LEC均表现为软组织影伴骨质破坏,3例伴骨质硬化;病变实性部分密度及信号较均匀,出现不同程度局部浸润。病变形态表现为局限性肿块及沿黏膜蔓延两种形式,其中条状息肉样肿块3例,球形肿块3例,沿鼻腔及鼻甲蔓延增厚1例。6例LEC患者行MRI动态增强扫描,最大强化指数(CImax)为1.51±0.46,流出率(WR)为14.26%±6.24%,时间信号强度曲线(TIC)平台型4例、流出型2例,达峰时间(Tpeak)为(40.09±4.59)s,呈迅速达峰表现。6例LEC患者行DWI检查,ADC值为(0.80±0.14)×10^-3 mm^2/s。LEC与ONB之间比较WR、ADC值差别有统计学意义(t=4.873,P=0.020;t=3.255,P=0.025)。结论LEC的影像表现具有一定特征,结合鼻腔鼻窦LEC常规影像学表现、功能MRI参数指标及临床资料等,有助于与其他鼻腔鼻窦恶性肿瘤鉴别。

Objective To investigate the CT and MRI features of sinonasal lymphoepithelial carcinoma(LEC)and to compare functional MRI index of LEC with olfactory neuroblastoma(ONB)in this area.Methods The clinical data,CT and MRI conventional findings of 7 patients were retrospectively reviewed.All of the patients,5 males and 2 females,with age of 35-58(45±9)years old,were histologically diagnosed as LEC of sinonasal tract at Beijing Tongren Hospital,Capital Medical University from February 2014 to November 2019.The semi-quantitative DCE-MRI parameters and ADC value were measured and compared with 18 cases of ONB which were collected during the same period.Independent sample t test or corrected t test,Fisher′s exact test were performed to compare the differences between the two groups.Results In all of the 7 LEC patients,6 lesions were located in naso-ethmoid area,1 lesion was located in naso-orbital area.Six lesions were on the left side,and another one was sitted on both sides.All tumors manifested irregular soft tissue density with bony destruction,3 of them showed bony sclerosis.All lesions showed homogeneous density or signal and obvious enhancement in solid portion accompanied with varying degrees of local invasion.Morphologically,two forms were observed:localized soft tissue mass and diffuse infiltration along mucosa.There were polypoid strips(n=3),spherical masses(n=3),and diffuse thickening of nasal cavity and turbinate mucosa(n=1).DCE-MRI examinations were performed in six LEC patients.Maximum contrast enhancement index(CImax)was 1.51±0.46,wash out ratio(WR)was 14.26%±6.24%.Time intensity curve(TIC)showed a plateau pattern(typeⅡ)in 4 cases and a washout pattern(typeⅢ)in 2 cases.Time to peak(Tpeak)were(40.09±4.59)s,showing a rapid peak performance.Diffusion weighted imaging was performed in six LEC patients,and the ADC value was(0.80±0.14)×10^-3 mm^2/s.There were statistical differences in WR and ADC values between sinonasal LEC and ONB(t=4.873,P=0.020 and t=3.255,P=0.025).Conclusion The radiological manifestations of LEC have certain characteristics.The characteristics of conventional imaging findings and functional MRI index combined with clinical data are helpful in making differential diagnosis between LEC and other sinonasal malignant tumors.