颅内非典型性畸胎样/横纹肌样肿瘤的MRI表现特征及其与Ki-67标记指数的相关性研究

MRI features of intracranial atypical teratoid/rhabdoid tumor and its correlation with the labeling index of Ki-67

目的探讨颅内非典型性畸胎样/横纹肌样肿瘤(atypical teratoid/rhabdoid tumor,AT/RT)的MRI表现特征及其与Ki-67标记指数的相关性。材料与方法回顾性分析本院2013年11月至2021年5月经手术病理证实的11例颅内AT/RT病例的MRI表现,并进一步研究MRI表现与Ki-67标记指数的相关性。结果11例颅内AT/RT中9例发生于后颅窝;肿瘤最大径为(37.08±2.57)mm;8例病灶出现囊变;6例病灶出现出血;3例病灶周围有轻度水肿;扩散加权成像(diffusion weighted imaging,DWI)(b=1000 s/mm2)示7例扩散受限高信号,4例轻度扩散受限稍高信号。1例患者未行MR增强扫描,其余7例呈明显不均匀强化,3例呈轻度不均匀强化。Ki-67标记指数范围为30%~80%,高表达组(Ki-67>40%)6例,低表达组(Ki-67≤40%)5例,两组在肿瘤位置、肿瘤最大径、瘤内出血、瘤内囊变、瘤周水肿、增强程度方面差异无统计学意义,但两组表观扩散系数(apparent diffusion coefficient,ADC)值差异有统计学意义(P<0.05)。Spearman秩相关分析显示ADC值与Ki-67标记指数呈负相关(r=-0.866,P<0.01)。结论颅内AT/RT常有囊变、出血,MRI信号多不均匀,增强扫描多呈不均匀明显强化;ADC值与Ki-67标记指数呈负相关。

Objective:To investigate the MRI features of intracranial atypical teratoid/rhabdoid tumors(AT/RT)and the correlation between MRI features and the labeling index of Ki-67.Materials and Methods:MRI features of 11 patients with intracranial AT/RT confirmed by the postoperative histopathology from November 2013 to May 2021 were retrospectively analyzed,and the correlation between MRI and the labeling index of Ki-67 was further studied.Results:Nine cases occurred in the posterior cranial fossa;the maximum diameter was(37.08±2.57)mm;cystic degeneration occurred in 8 cases,hemorrhage in 6 cases,and mild edema around the focus in 3 cases.In diffusion weighted imaging(DWI)(b=1000 s/mm2),7 cases showed high signal and 4 cases showed slightly high signal.MR enhanced scan was not performed in 1 case,7 cases showed obvious inhomogeneous enhancement and 3 cases showed mild inhomogeneous enhancement.The range of Ki-67 was 30%–80%;there were 6 cases with high expression(Ki-67>40%)and 5 cases with low expression(Ki-67≤40%).There was no significant difference between the two groups in the location and size of lesions,intratumoral hemorrhage,intratumoral cystic degeneration,peritumoral edema and enhancement degree.However,there was significant difference in apparent diffusion coefficient(ADC)value between the two groups(P<0.05).Spearman correlation analysis showed that ADC value was negatively correlated with the labeling index of Ki-67(r=-0.866,P<0.01).Conclusions:Intracranial AT/RT always has cystic degeneration,hemorrhage,and most of them have inhomogeneous signal intensity on MRI and obvious inhomogeneous enhancement on enhanced scan;ADC value was negatively correlated with the labeling index of Ki-67.