胚胎发育不良性神经上皮肿瘤

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胚胎发育不良性神经上皮肿瘤

图1 男性，18岁，主因癫发作4年、头痛头晕10 d入院。头部影像学显示左侧额颞叶囊实性占位征象。手术切除左侧额颞叶占位性病变。术后病理证实胚胎发育不良性神经上皮肿瘤（WHOⅠ级）1a横断面CT显示，左侧额颞叶低密度影，其内侧壁可见斑片样高密度结节影（箭头所示）1b横断面T1WI显示，左侧颞叶囊性占位征象，囊液呈低信号，信号强度高于脑脊液（箭头所示）；其内侧壁稍高信号结节影1c横断面T2WI显示，病变内囊液呈高信号，附壁结节呈等信号（箭头所示）；瘤周无水肿1d横断面FLAIR成像显示，邻近病变内侧壁高信号影（箭头所示）1e横断面增强T1WI显示，病变内侧壁实性区斑片样强化（箭头所示），囊壁未见强化Figure 1 An 18-year-old male was hospitalized because of epilepsy for 4 years and headache for 10 d.MRI showed a cystic solid mass located in left fronto-temporal lobe.The lesion was totally resected and postoperative pathological diagnosis was dysembryoplastic neuroepithelial tumor(DNT, WHOⅠ).Axial CT showed hypodensity shadow in left fronto-temporal lobe with patchy hyperdensity nodule located in its medial wall(arrow indicates,Panel 1a).Axial T1WI revealed a cystic mass with hypointensity,which was slightly higher than cerebrospinal fluid,located in left temporal lobe(arrow indicates).A mural nodule with slightly high-intensity was found in the medial wall(Panel 1b).Axial T2WI showed high-intensity cystic fluid with an isointensity mural nodule(arrow indicates).No edema was found in the surrounding tissue(Panel 1c).Axial fat suppression FLAIR showed high-intensity signal adjacent to medial wall of lesion(arrow indicates,Panel 1d).Axial enhanced T1WI showed patchy enhancement in solid component of medial wall(arrow indicates)and no enhancement was found in the cystic wall(Panel 1e).

胚胎发育不良性神经上皮肿瘤（DNT，WHOⅠ级）是中枢神经系统少见良性肿瘤，属神经元和混合性神经元-胶质肿瘤范畴。1988年由Daumas-Duport等首次命名。多见于儿童和青年，好发于大脑皮质，颞叶最为多见，其次为额叶，基底节、脑室、脑干、小脑、透明隔和胼胝体等亦有报道，肿瘤生长缓慢，临床主要表现为难治性癫，预后良好，术前明确诊断十分重要。典型胚胎发育不良性神经上皮肿瘤呈底部位于大脑皮质、尖部朝向脑深部的楔形或脑回样结构，囊性或囊实性，边界清晰，瘤周无水肿，无明显占位征象，邻近大脑皮质可并存皮质发育不良。CT表现为皮质和皮质下界限清晰的低密度影（图1a），20%病灶可见斑片样钙化；位于大脑凸面的肿瘤因生长缓慢致颅骨内板受压变薄。MRI显示病灶内多发结节样和假囊性结构，T1WI呈低信号，信号强度略高于脑脊液（图1b）；T2WI可见囊性或多囊性“肥皂泡”样结构，呈高信号（图1c），部分病变内有分隔；FLAIR成像呈略低或高信号，病变边缘可见线样、斑片样或环形更高信号带，即“环形征”（图1d），具有诊断特异性，可能与肿瘤边缘围绕含胶质-神经元成分的疏松组织有关。部分病变可见附壁结节，信号强度略高于大脑皮质。增强扫描可见少部分病变内或边缘线样、斑片样、结节样或环形强化（图1e），系增生的神经胶质细胞伴血管增生所致。应注意与位于皮质和皮质下的囊性肿瘤、带附壁结节的肿瘤（如节细胞胶质瘤、多形性黄色星形细胞瘤、毛细胞型星形细胞瘤、少突胶质细胞瘤）相鉴别。

（天津市环湖医院神经放射科韩彤供稿）

Dysembryoplastic neuroepithelial tumor

HAN Tong
Department of Neuroradiology,Tianjin Huanhu Hospital,Tianjin 300350,China(Email:mrbold@163.com)

10.3969/j.issn.1672-6731.2017.01.015