胚胎發(fā)育不良性神經(jīng)上皮腫瘤

·臨床醫(yī)學圖像·

胚胎發(fā)育不良性神經(jīng)上皮腫瘤

圖1 男性，18歲，主因癲發(fā)作4年、頭痛頭暈10 d入院。頭部影像學顯示左側(cè)額顳葉囊實性占位征象。手術切除左側(cè)額顳葉占位性病變。術后病理證實胚胎發(fā)育不良性神經(jīng)上皮腫瘤（WHOⅠ級）1a橫斷面CT顯示，左側(cè)額顳葉低密度影，其內(nèi)側(cè)壁可見斑片樣高密度結節(jié)影（箭頭所示）1b橫斷面T1WI顯示，左側(cè)顳葉囊性占位征象，囊液呈低信號，信號強度高于腦脊液（箭頭所示）；其內(nèi)側(cè)壁稍高信號結節(jié)影1c橫斷面T2WI顯示，病變內(nèi)囊液呈高信號，附壁結節(jié)呈等信號（箭頭所示）；瘤周無水腫1d橫斷面FLAIR成像顯示，鄰近病變內(nèi)側(cè)壁高信號影（箭頭所示）1e橫斷面增強T1WI顯示，病變內(nèi)側(cè)壁實性區(qū)斑片樣強化（箭頭所示），囊壁未見強化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).

胚胎發(fā)育不良性神經(jīng)上皮腫瘤（DNT，WHOⅠ級）是中樞神經(jīng)系統(tǒng)少見良性腫瘤，屬神經(jīng)元和混合性神經(jīng)元-膠質(zhì)腫瘤范疇。1988年由Daumas-Duport等首次命名。多見于兒童和青年，好發(fā)于大腦皮質(zhì)，顳葉最為多見，其次為額葉，基底節(jié)、腦室、腦干、小腦、透明隔和胼胝體等亦有報道，腫瘤生長緩慢，臨床主要表現(xiàn)為難治性癲，預后良好，術前明確診斷十分重要。典型胚胎發(fā)育不良性神經(jīng)上皮腫瘤呈底部位于大腦皮質(zhì)、尖部朝向腦深部的楔形或腦回樣結構，囊性或囊實性，邊界清晰，瘤周無水腫，無明顯占位征象，鄰近大腦皮質(zhì)可并存皮質(zhì)發(fā)育不良。CT表現(xiàn)為皮質(zhì)和皮質(zhì)下界限清晰的低密度影（圖1a），20%病灶可見斑片樣鈣化；位于大腦凸面的腫瘤因生長緩慢致顱骨內(nèi)板受壓變薄。MRI顯示病灶內(nèi)多發(fā)結節(jié)樣和假囊性結構，T1WI呈低信號，信號強度略高于腦脊液（圖1b）；T2WI可見囊性或多囊性“肥皂泡”樣結構，呈高信號（圖1c），部分病變內(nèi)有分隔；FLAIR成像呈略低或高信號，病變邊緣可見線樣、斑片樣或環(huán)形更高信號帶，即“環(huán)形征”（圖1d），具有診斷特異性，可能與腫瘤邊緣圍繞含膠質(zhì)-神經(jīng)元成分的疏松組織有關。部分病變可見附壁結節(jié)，信號強度略高于大腦皮質(zhì)。增強掃描可見少部分病變內(nèi)或邊緣線樣、斑片樣、結節(jié)樣或環(huán)形強化（圖1e），系增生的神經(jīng)膠質(zhì)細胞伴血管增生所致。應注意與位于皮質(zhì)和皮質(zhì)下的囊性腫瘤、帶附壁結節(jié)的腫瘤（如節(jié)細胞膠質(zhì)瘤、多形性黃色星形細胞瘤、毛細胞型星形細胞瘤、少突膠質(zhì)細胞瘤）相鑒別。

（天津市環(huán)湖醫(yī)院神經(jīng)放射科韓彤供稿）

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