海绵状血管瘤

1、颅内海绵状血管瘤颅内海绵状血管瘤 (intracranialcavernousangiomas,ICA) 2005-8-26 起源与病变部位：起源与病变部位：研究证明海绵状血管瘤是一种不 完全外显性的常染色体显性遗传性疾病，基因位于 第7条染色体上 发病率：发病率：占脑血管畸形的25.1% ；人群发生率约为 0.4%0.8% 分类：分类：脑内型与脑外型 脑内型发生在大脑半球占77%90%，病灶主要位于皮质下区 脑外型海绵状血管瘤较少见,常见于中颅窝底、鞍旁等部位, 尤其海绵窦区。由于与硬膜关系密切,又称为硬膜型海绵状 血管瘤 海绵状血管瘤是一种较常见的先天性血管畸形海绵状血管瘤是一种较常见的先

2、天性血管畸形 Zabramski的分型标准 I型为亚急性出血者 II型为病灶反复出血及血栓形成者 III型为慢性出血者 IV型可能为微小ICA或毛细血管扩张症 临床特点临床特点 见于各年龄组,然以3050岁居多,男女比例大致相等 临床上常表现为反复出血和癫痫,进而可引起神经功能 缺失,甚至危及生命 该瘤通常单发，单发病灶无症状患者占11%44 多发者仅6%13.4%,且多见于女性或有家族史者。多发性ICA临 床上往往出现神经系统多个部位受损的症状和体征，而病程较 单发ICA者短,而癫痫、颅高压及神经系统局灶症状体征多见, 并可出现皮质功能减退的表现 可伴发血管皮肤和其它脏器血管畸形及颅内和椎管

3、内 其它肿瘤 影像表现影像表现 脑内CA直径多较小，在23cm左右，脑外病灶直径 相对较大 CTCT平扫平扫表现为高密度,病灶中心常可见斑点状钙化， 增强扫描病灶多呈轻至中度强化,如有血栓形成也 可以不强化 MRIMRI表现表现具有一定的特异性，边界清晰,病灶周围无 或轻度水肿,无或有轻微占位效应。T1WI以等信号 为主，T2WI以高信号为主的混杂信号，周边有环形 或弧形低信号带环绕，混杂信号与病变内钙化、含 铁血黄素沉积及不同时期出血有关 （与动静脉畸形的鉴别:后者病灶多较边界不清，形态不规 则，密度或信号不均匀，MRI示灶内常见流空的血管） 病理表现病理表现 海绵状血管瘤为红色圆形或分叶状

4、血管团,形似草 莓或桑葚,切面如海绵状。与AVM不同,海绵状血管 瘤血流速度不快,缺乏明显的供血动脉及引流静脉 光镜下,病灶由窦状扩张的畸形静脉血管组成,血 管壁薄,有单层的内皮细胞和较薄的外膜,缺乏肌 层和弹力纤维,管腔内充满血液，病灶内见不同时 期的出血、血栓、钙化,出血腔的再上皮化，血管 的增生和肉芽组织的增生可以使海绵状血管瘤增 大。病灶周边也常可见含铁血黄素沉着及反应性 胶质增生，病灶内不含神经组织且分界清晰而有 别于其它血管畸形。它可发生于中枢神经系统的 任何部位,以颅内幕上多见 治疗治疗 理想的治疗方法尚未确定。有认为对无症 状的较小CA可在临床及CT或MR监护下行保 守治疗，而

5、多数认为手术切除是治疗CA的 主要手段。手术死亡率为2.7%7.5%，手术 方法及效果取决于病灶位置。 Figure 1. Type 1 cavernous angioma in a symptomatic 8-year-old girl. (a) Transverse T1-weighted SE MR image shows a large lesion that includes a high- signal-intensity area (arrow) and a low-signal-intensity area (arrowhead) suggestive of recent bl

6、eeding in the left centrum ovale. (b) Transverse intermediate-weighted SE MR image confirms the presence of a large hemorrhagic lesion (arrow) in the left centrum ovale. The lesion is surrounded by edema (arrowhead). The diagnosis of acute hemorrhage related to a type 1 cavernous angioma was confirm

7、ed at surgery and pathologic analysis. Figure 2. Type 2 cavernous angioma in an asymptomatic 24-year-old man. (a) Transverse T1-weighted SE MR image shows a cavernous angioma in the right cingulate gyrus. The lesion includes a central reticulated core (arrow) and a peripheral low-signal-intensity ri

8、m (arrowhead). (b) Transverse T2-weighted fast SE MR image helps confirm the presence of a type 2 cavernous angioma in the right cingulate gyrus. The lesion has a core of heterogeneously high signal intensity (straight arrow) and a peripheral rim of low signal intensity (arrowhead) related to hemosi

9、derin deposition. A second cavernous angioma (curved arrow) with the same MR imaging features is clearly demonstrated in the left frontal ascending gyrus. The surrounding rim is better demonstrated with a T2- weighted sequence, as in b, than with a T1-weighted sequence, Figure 3. Type 3 cavernous an

10、gioma in an asymptomatic 43-year-old man. Transverse T2-weighted SE MR image (3,000/98) shows a small cavernous angioma (arrow) in the right cerebral hemisphere, close to the third ventricle and characterized by homogeneously low signal intensity. Figure 4. Type 4 cavernous angioma in an asymptomati

11、c 40-year-old woman. Transverse T2-weighted GRE MR image shows a small low-signal-intensity lesion (arrow) in the right cerebellar hemisphere. . Imaging:The spin echo images demonstrate a well circumscribed berrylike lesion in the posterior midpons, which is characterized by mixed signal intensity, rim of hemosiderin, inhomogenous gadolinium enhancement, and absence of surrounding edema History: This 53-