原发性颅内异位生殖细胞瘤的MRI诊断

MRI Diagnosis of Primary Intracranial Ectopic Germinomas

目的探讨原发性颅内异位生殖细胞瘤(IEGs)MRI特征表现,以提高诊断准确率。方法回顾性分析本院2015年8月至2020年8月全部经手术病理证实的20例IEGs患者MRI资料。所有患者均行常规MRI检查。系统分析不同部位的IEGs的MRI特征表现。结果 20例患者,男16例,女4例,年龄7~35岁,平均(18.15±8.79)岁。发病部位为基底节-丘脑区9例(单侧基底节区7例,双侧基底节区及丘脑2例),大脑半球5例(其中1例累及同侧基底节区及丘脑),脑室系统5例,脑干1例。其中18例发生囊变,瘤内出血15例,瘤周水肿10例,7例伴轻度脑积水。不同部位IEGs的MRI表现各异,基底节生殖细胞瘤囊变、出血多见,增强后轻中度不均匀强化,病变累及基底节-丘脑区的10例患者均出现同侧大脑和/或脑干偏侧萎缩改变;脑室生殖细胞瘤出血多见;脑干生殖细胞瘤以囊变为主,增强扫描呈明显不均匀强化;额叶生殖细胞瘤MRI表现多样,可呈实性或囊变;另见2例合并松果体区结节。结论不同部位的IEGs具有不同的MRI特征表现,熟练掌握其影像特征,结合患者发病年龄、性别,有助于提高IEGs的诊断准确率,从而指导临床选择合适的诊疗方案。

Objective To investigate the MRI features of primary intracranial ectopic germinoma in order to improve the diagnostic accuracy. Methods The MRI data of 20 patients with intracranial ectopic germinoma confirmed by operation and pathology from August 2015 to August 2020 were analyzed retrospectively. All patients underwent routine MRI examination. The MRI features of ectopic germinoma in different parts of the brain were analyzed systematically. Results Among the 20 patients, there were 16 males and 4 females, aged from 7 to 35 years old, with an average of(18.15 ±8.79) years. The lesions were located in the basal ganglia-thalamus region in 9 cases(unilateral basal ganglia in 7 cases, bilateral basal ganglia and thalamus in 2 cases), cerebral hemisphere in 5 cases(including 1 case involving ipsilateral basal ganglia and thalamus), ventricular system in 5 cases and brain stem in 1 case. Cystic degeneration occurred in 18 cases, intratumoral hemorrhage in 15 cases, peritumoral edema in 10 cases, and mild hydrocephalus in 7 cases. The MRI findings of tumors in different sites were different: cystic degeneration and hemorrhage were common in basal ganglia germinoma, mild to moderate inhomogeneous enhancement after enhancement, ipsilateral brain and/or brainstem hemiatrophy were found in 10 patients with lesions involving the basal ganglia-thalamus area, ventricular germinoma hemorrhage was common, brainstem germinoma was mainly cystic, and enhanced scan showed obvious inhomogeneous enhancement. Frontal lobe germinoma showed various MRI manifestations, which could be solid or cystic, and 2 cases were complicated with pineal nodules. Conclusion Intracranial germinomas in different locations have different MRI features. A good understanding of the imaging features, combined with their gender and age of onset will help to improve the diagnostic accuracy of intracranial ectopic germinoma and guide the clinical selection of appropriate diagnosis and treatment.