中枢神经系统原发性黑色素肿瘤的MRI诊断分析

MRI Diagnosis of Primary Melanocytic Neoplasms in the Central Nervous System

目的分析、总结中枢神经系统(CNS)原发性黑色素肿瘤的MRI特征。方法回顾性分析8例经手术病理证实的CNS原发性黑色素肿瘤的MRI表现。8例均行MRI平扫和增强。结果恶性黑色素瘤6例,幕上5例,幕下1例,均为单发,其中2例侵犯邻近颅骨。黑色素细胞瘤2例,幕上单发1例,椎管内3个病灶1例。3个瘤灶呈黑色素型,5个为中间型,2个为无黑色素型。5例可见出血,无一例出现囊变或钙化,6个瘤灶出现不同程度的瘤周水肿。4个瘤灶均匀明显强化,2个呈环形强化,4个不均匀强化。结论 CNS原发性黑色素肿瘤的MRI表现具有一定特征,MRI对黑色素肿瘤具有较高的诊断价值。

Objective To analyze and summarize the MRI characteristics of melanocytic neoplasms in the central nervous system（CNS）. Methods MRI features of 8 cases （5 males and 3 females with the age ranging from 15 to 53 years） with CNS primary melanocytic neoplasms proved by surgical and histological results were analyzed retrospectively. All patients received plain and enhanced MR scanning. Results There were 6 cases of single primary malignant melanomas, 5 lesions located at supratentorial region and 1 at cerebellum, and skull bone invasion was found in 2 cases; 2 cases of meningeal melanocytomas presented as single supratentorial lesion in 1 case and 3 intraspinal lesions in another one. Three lesions were presented as melanotic, 2 as amelanotie as well as 5 intermediate. Hemorrhage was noted in 5 lesions and peritumoral edema in 6 lesions. Cystic changes or calcifications were not found in any cases. Four tumors were exhibited remarkable and homogeneous enhancement, 2 with rim shaped enhancement and 4 with heterogeneous and diffuse enhancement after administration of contrast agents. Conclusion The CNS primary melanocytic neoplasms have some MRI features, and MRI has higher value in the diagnosis of melanocytic tumors.