外周性原始神经外胚层肿瘤的CT、MRI表现与病理对照分析

目的 分析外周性原始神经外胚层肿瘤（pPNETs）的CT与MRI表现，以提高对本病的认识。方法 回顾性分析经病理证实的19例pPNETs的CT和MRI表现。患者发病年龄7～57岁，中位年龄22岁；男11例、女8例。19例全部行CT检查，其中13例同时行MR检查。结果 3例病灶位于颅内，7例位于四肢，2例位于胸部，4例位于腹部，3例位于脊柱。软组织pPNETs的CT表现为大的、边界不清的软组织肿块，密度不均匀伴坏死囊变，不伴钙化，增强后呈不均匀强化。骨pPNETs主要表现为较大的溶骨性骨质破坏伴软组织肿块，有1例可见瘤骨形成，增强后呈不均匀强化。在MRSE T1WI上表现为等肌肉信号，T1WI上表现为不均匀高信号，部分病例可见假包膜改变。免疫组织化学结果，肿瘤均表达CD99，并不同程度地表达上皮细胞膜抗原（EMA）、突触素（Syn）、胶质纤维酸性蛋白（GFAP）等，但不表达白细胞共同抗原（LCA）等。结论 pPNETs的CT与MRI缺乏特征性表现，但能较好的显示肿瘤的内部结构、明确肿瘤的范围，有助于该病的鉴别诊断、指导制定治疗方案、检出远处转移和评价治疗效果。     

原始神经外胚叶肿瘤的影像诊断

目的分析原始神经外胚叶肿瘤(PNET)的CT、MRI表现,以提高对该病的认识。方法回顾分析29例经病理证实的PNET的临床表现和CT、MRI征象。结果原发于上肢PNET 3例,上颌窦1例,肺1例,纵隔2例,腹膜后2例,颈部1例,下肢2例,额叶6例,颞叶3例,脑室内3例,CPA区1例,椎管内2例,盆腔内2例。病灶体积较大,呈浸润生长,推压邻近结构,并可凸入椎管。肿瘤密度/信号不均,CT为软组织密度,轻至中度强化;MR T1WI肿块与肌肉等信号,T2WI呈不均匀高信号,增强扫描呈花环状或蜂窝状强化。3例有钙化,2例邻近骨质破坏,呈溶骨性破坏伴骨膜反应。肿瘤DWI上呈高信号,ADC值低于其他颅内原发性肿瘤。结论 PNET的常规MRI表现和DWI特点有助于其术前定性诊断和鉴别诊断。     

肾脏原始神经外胚层肿瘤的CT诊断及病理分析

原始神经外胚层肿瘤(primitive neuroectodemal tumor, PNET)临床较为少见,分为中枢型和外周型,而组织来源于肾脏的外周型 PNET 更为少见,与其影像征象相关的文献报道较少。笔者回顾性分析6例经手术、病理证实的肾脏 PNET,进行病理与影像学对比分析,探讨影像学对其诊断的价值,以提高本病的诊断准确性。     

外周性原始神经外胚层肿瘤的影像学诊断

目的:探讨外周性原始神经外胚层肿瘤(pPNET)的影像学诊断价值,提高对本病的认识.方法:搜集我院经手术病理及免疫组化证实的pPNET 9例.CT检查6例,其中4例增强扫描;MRI平扫 增强检查3例;超声检查4例,分析pPNET的影像学表现特点.结果:发生于后胸壁2例,腰骶部、肩胛骨、鞍结节、鼻腔、颈部、右上臂及卵巢各1例.pPNET多表现为较大实体软组织肿块,成分混杂,血供相对较丰富,呈不均匀性强化;起源骨组织者以溶骨破坏为主,周围见明显软组织肿块;起源于胸壁pPNET常伴有胸膜侵犯及邻近肋骨骨质的破坏.结论:影像学检查能较好地显示pPNET大小、范围及其毗邻关系,对于青少年出现溶骨性破坏伴较大软组织肿块或软组织内见较大异质性肿块应考虑本病的可能,定性诊断仍依赖于病理学检查.     

腹膜后外周型原始神经外胚层肿瘤的MSCT表现及其病理基础

目的 :探讨腹膜后外周型原始神经外胚层肿瘤(p PNETs)的MSCT特征,提高对该病的认识。方法 :回顾性分析7例经手术病理证实的腹膜后p PNETs的MSCT资料。结果:7例均为单发,且均位于肾脏周围间隙;直径6.3~15.7 cm,平均9.7 cm;4例形态不规则,3例呈类圆形,境界多不清楚。CT平扫多为略低密度,病灶内部密度不均匀;均出现不同程度的坏死、囊变,5例肾旁病灶坏死、囊变显著,呈囊实性肿块;4例伴出血;均未见钙化。增强扫描多表现为轻中度进行性不均匀持续强化,病灶强化方式多样,实质部分呈片状、结节状及网条状强化,3例内见肿瘤血管;6例肿块边缘见类包膜样改变,但包膜多不完整,外缘可见小毛刺样改变。7例肿瘤均不同程度推挤或侵犯邻近脏器、大血管,并向邻近脂肪间隙浸润,形成强化条索影;3例患侧肾脏实质灌注下降,3例伴肾门淋巴结转移,2例伴骨盆转移;7例均未见明显腹腔积液。结论:腹膜后p PNETs的MSCT表现虽缺乏特征性,但能较好地显示肿瘤的内部结构、明确肿瘤的范围,有助于该病的鉴别诊断。     

Radiologic characteristics of primitive neuroectodermal tumors in children

Radiographic findings are reviewed in 31 children with primitive neural ectodermal tumors seen at the Hospital for Sick Children from 1962 through 1983. Seventeen children were initially evaluated with computed tomography (CT). Ten of these had both CT studies and angiography. The tumors were large, irregular, typically iso- to hyperdense, and showed dense, heterogeneous contrast enhancement. Cysts were present in 65% and calcifications in 71% of cases. The angiographic findings were nonspecific, ranging from avascular to markedly vascular. Although these tumors were usually found in the cerebral hemisphere, particularly the frontal lobes, two cases are included of tumors arising elsewhere: one in the pineal and one in the suprasellar region. Epidemiologic data are reviewed.     

腹盆部外周型原始神经外胚层瘤的CT 诊断与病理分析

目的：分析腹盆部外周型原始神经外胚层瘤(pPNET)的临床特点、CT 表现及其与病理的联系,提高对本病的认识。方法回顾性分析23例经病理证实的腹盆部 pPNET 的 CT 表现、临床资料及病理特征。结果(1)所有患者术前临床及影像资料完整。(2)23例病灶 CT 表现多为大小不一、边界模糊的肿块影,平均直径约10.72 cm;9例呈不同程度的囊变坏死,2例见小片状出血灶,4例出现点状钙化。CT 增强后多数呈不均匀轻中度强化,囊变、坏死更明显。12例出现不同程度的复发、周围侵犯或远处转移,5例合并癌栓形成,4例见肿瘤滋养血管。(3)免疫组化示19例 CD99表达,11例 CD56表达,12例 Vim(波形蛋白)表达,11例 Syn(突触素)表达,4例 NSE(神经元特异性烯醇化酶)表达,4例 FLI-1表达及4例 EMA(上皮细胞抗原)表达。结论腹盆部pPNET 发病年龄较小且恶性程度高,常为较大不均匀肿块,多伴囊变坏死,浸润性生长,增强后实性成分多呈渐进性轻中度强化。     

外周原始神经外胚叶肿瘤CT、MRI及病理分析

目的 研究外周原始神经外胚叶肿瘤的CT、MRI表现及病理特征.方法 回顾性分析经病理证实的9例外周原始神经外胚叶肿瘤的临床、影像及病理资料.4例行CT检查,5例行MRI检查.结果 本组9例,上颌窦2例,胸壁2例,股骨、眼眶、椎管、肩部及腋窝各1例.8例肿瘤为单发,类圆形多见,5例为软组织肿块伴邻近骨质破坏,囊变坏死少见,未见钙化,CT平扫密度多均匀,MRI平扫为T1等肌肉信号、T2不均匀高信号,增强扫描多为明显强化.2例出现淋巴结转移.肿瘤免疫组化均表达CD99,不表达白细胞共同抗原(LCA).结论 外周原始神经外胚叶肿瘤的CT及MRI表现为非特异性,但能很好地显示肿瘤及侵袭范围,其最终诊断依靠病理和免疫组织化学检查.     

Neuroradiology of primitive neuroectodermal tumors

Summary The neuroradiological findings in four cases of primitive neuroectodermal tumor of the cerebrum are described. These highly malignant neoplasms of childhood present as large, enhancing cerebral masses with extensive neovascularity. Cerebrospinal fluid seeding is common and distant extraneural metastases may occur.     

外周性原始神经外胚层瘤的影像表现

目的:探讨外周性原始神经外胚层肿瘤的影像学表现.方法:回顾性分析经病理证实的12例外周性神经外胚层瘤的影像学资料.9例行CT扫描,4例行MR扫描,其中1例行DSA检查.结果:胸壁软组织5例,右肺下叶1例,肱骨2例,股骨1例,胫骨1例,脊椎2例.胸壁软组织的pPNETs CT平扫表现为大而边界欠清的软组织肿块,内见坏死,无钙化,增强后明显不均匀强化.右肺下叶的pPNETs CT平扫表现为分叶状肿块,内见少量出血,边界清晰,增强后明显强化.长骨pPNETs表现为溶骨性骨质破坏伴巨大软组织肿块,无钙化,无骨膜反应.T1WI上表现为等或低信号,T2 WI上表现为不均匀高信号,增强后明显强化.脊椎pPNETs表现为椎体或附件骨质破坏伴软组织肿块,不累及椎间盘,其中1例骶骨pPNETs DSA检查示肿瘤由髂内动脉供血和大量新生血管.结论:CT和MRI均能很好地显示pPNETs的内部结构、病变范围、有无侵犯毗邻组织器官或远处转移.DSA可明确肿瘤供血动脉和反映新生肿瘤血管丰富的特点,可作为一种补充检查方法.确诊仍需依靠病理和免疫组化检查.     

Diffusion-weighted imaging and fluid attenuated inversion recovery imaging in the evaluation of primitive neuroectodermal tumors

The aim of our study was to determine whether fluid-attenuated inversion recovery (FLAIR) imaging and diffusion-weighted imaging (DWI) would be helpful in characterizing primitive neuroectodermal tumors (PNET) from other pediatric brain tumors. We expected that the compact cellular nature and the relatively small extracellular space of this tumor would affect the signal intensity on both pulse sequences relative to the more sparsely cellular glial tumors that have larger extracellular spaces. Eighteen pediatric patients with PNET were examined on a 1.5 T MRI with routine imaging plus FLAIR and compared with 28 patients with non-PNET. DWI was also performed in 7 PNET and 18 non-PNET. Seventy-eight percent of PNET were isointense to gray matter on FLAIR while 82 % of non-PNET were hyperintense and only one was isointense (3 %). Diffusion was abnormally restricted in all 7 PNET examined (100 %) but was restricted in non-PNET in only 1 out of 18 (6 %) patients who had DWI. The differences in the histologic architecture between PNET and non-PNET are reflected in both FLAIR imaging and in DWI. Received: 3 February 2001/Accepted: 13 February 2001     

Computed tomography of primitive neuroectodermal tumors

The primitive neuroectodermal tumor is a neoplasm of young individuals that occurs predominantly in the supratentorial compartment. It appears on computed tomography as a bulky mass, often with calcification with predominantly homogeneous enhancement but on occasion with cystic or necrotic areas. Cerebrospinal fluid seeding was observed in more than half the cases in our series. The patients had a short survival period (7-24 months). Despite surgery, radiation, and chemotherapy, further growth of this tumor has not been prevented.     

外周性原始神经外胚层肿瘤的CT表现

目的：探讨外周性原始神经外胚层肿瘤（pPNETs)的CT特征,提高对本病的认识水平。方法：回顾分析6例经病理证实的pPNETs CT表现。结果：5例发生在骨骼的pPNETs,CT表现为溶骨性骨质破坏和明显的软组织肿块。骨质破坏区无骨膜增生、骨质硬化和瘤骨形成;软组织肿块的密度可均匀或不均匀。1例放疗后软组织肿块有明显缩小。1例发生在右胸腔的pPNETs(Askin瘤）,CT表现为巨大软组织肿块,侵犯纵隔,密度不均匀,有中度不均匀强化,周围骨骼无破坏。手术切除后4个月,在右胸壁再发密度均匀的小肿块,有中度均匀强化。结论：pPNETs的CT表现缺乏特征性,但能较好地显示肿瘤的内部结构、明确肿瘤的范围,且助于本病的鉴别诊断、判断手术可切除性、检出远处转移和评价治疗效果。     

幕上原始神经外胚叶瘤的影像学表现

目的 探讨幕上原始神经外胚叶瘤（SPNET）的MRI及CT特征。方法 回顾性分析10例经手术病理证实的SPNET的MRI及CT表现。结果 SPNET的影像学表现有以下特点；（1）肿瘤呈类圆形，边界清楚，病灶周围无水肿或水肿较轻，且大部分位于中线附近及侧脑室旁，少数位于皮层下；（2）MRI示肿瘤实质T1WI呈稍低或等倍，T2WI呈等信号，与脑灰质信号相等，增强较明显。（3）CT示肿瘤实质呈稍高密度，影像学表现与髓母细胞瘤相似。（4）中线附近的肿瘤为实体结构。无囊变；囊变明显的肿瘤多们于皮质下。（5）部分肿瘤内有出血或钙化，有的可见到脑脊液扩散灶。结论 SPNET影像学表现有一定特征。结合其影像学表现及临床症状有助于与其他肿瘤区分。     

外周原始神经外胚层肿瘤的 CT及MRI 表现

目的：探讨外周原始神经外胚层肿瘤（pPNET ）的CT 及MRI表现。方法回顾性分析9例经病理证实的pPNET 的CT、MRI表现及病理特点。其中8例行CT平扫和（或）增强扫描;5例行MRI平扫和（或）增强扫描。结果病灶位于头颈部2例,胸部3例,阴囊1例,右肩胛区1例,下肢2例。病灶7例为单发,呈类圆形或不规则形,分叶状,最长径约为1．6～13．8cm,平均6．2cm。8例与周围组织分界不清。CT平扫呈以等密度为主的混杂密度;MRI平扫 T1WI为等稍低信号,T2WI多为不均匀高信号。增强扫描呈多种强化表现,常见为中度以上不均匀强化。其中3例与邻近骨关系密切,表现为溶骨性骨质破坏。结论 pPNET CT及M RI表现缺乏特征性,对临床的定位及定性诊断有一定的帮助。     

幕上及椎管内原始神经外胚层肿瘤的MRI诊断

目的　探讨幕上及椎管内原始神经外胚层肿瘤的MRI特点 ,以提高正确诊断率。方法分析经手术病理证实的 9例原始神经外胚层肿瘤的MRI表现 ,其中男 6例 ,女 3例 ,平均年龄 32 6岁。术前 9例均行MR常规平扫检查 ,分别采用SE、快速自旋回波 (FSE)、液体衰减翻转恢复 (fluidattenuatedinversionrecovery ,FLAIR)序列 ;其中 2例行扩散加权成像 (diffusionweightedimaging ,DWI) ,4例行增强检查。结果　幕上大脑半球 8例 ,包括额颞区与枕叶各 2例 ,额顶、顶、额各 1例 ,第3脑室后部 1例。胸段椎管内 1例。病灶普遍较大 ,最大为 6 0cm× 6 9cm× 4 9cm。除第 3脑室后部 1例病变呈类圆形外 ,其余 7例形态极不规则 ,且水肿相对较轻 ,边界清楚 ,偏实性多见。其中发生小的囊变者 2例、合并出血 4例 ,3例病灶内可见血管流空影。呈稍长T1WI信号、长或稍长T2 WI信号 4例 ;混杂T1WI、T2 WI、FLAIR信号 4例 ;DWI 2例显示为明显高信号。其中增强 3例呈极不均一不规则“印戒”样强化 ,并显示室管膜扩散。椎管内 1例呈不规则形软组织肿块影 ,伴相邻骨质破坏肌群受累 ,显示轻度增强。结论　原始神经外胚层肿瘤的MR表现较具特征性 ,但其确诊仍依赖病理学诊断。     

幕上原始神经外胚层肿瘤的MRI表现及病理基础

目的 探讨幕上原始神经外胚层肿瘤(SPNET)的MRI表现及病理学基础,旨在提高对该病的影像学认识.方法 回顾性分析18例经病理证实为SPNET的MRI表现,并与手术病理相对照,探讨不同病例MRI表现不相同的病理学基础.结果 病灶位于额叶8例,顶叶3例,颞顶叶2例,颞叶、额顶叶、额颞叶、枕叶及侧脑室旁各1例.病灶普遍较大(3.8～9.6 cm),形态不规则10例,边界清楚14例,病灶均呈囊实性肿块,信号不均匀,实质部分T1 WI呈等或稍低信号,T2 WI及FLAIR呈等或稍高信号.囊变多位于周边,可见出血、流空血管影、钙化.瘤周无水肿9例,轻度水肿7例,中度水肿2例,占位效应均显著,邻近颅骨可受侵.增强后病灶明显不均匀强化16例,均匀强化1例,未见强化1例.病理组织显示肿瘤由低分化的排列紧密的小圆细胞构成,可向多种细胞分化,间质血管丰富;免疫表型以NSE、Vim、CD99、GFAP、Syn表达为主.结论 SPNET的MRI表现与其病理学基础密切相关,确诊仍需病理组织学及免疫组化检查.     

骨外周性原始神经外胚层瘤的影像学表现

目的探讨骨外周性原始神经外胚层瘤(pPNETs)的临床和影像学表现。方法分析10例骨pPNETs的临床和X线、CT及MR影像资料。结果pPNETs多以局部疼痛(9例)伴肿块(7例)为主诉。X线示溶骨性骨质破坏8例，伴有不规则硬化和轻度膨胀的溶骨性骨质破坏1例，未见异常1例；7例见软组织肿块；均未见骨膜反应。7例CT扫描中，边界不清的溶骨性骨质破坏6例。伴有不规则硬化和轻度膨胀的溶骨性骨质破坏1例，均有软组织肿块形成，2例伴有细小的点状钙化，均未见骨膜反应；10例MR扫描中，9例在T1WI呈等信号，1例呈中等偏高信号；在T2WI和短时反转恢复(STIR)序列，8例呈不均匀中、高信号，2例呈均匀高信号；均见明显软组织肿块形成；4个疗程化疗以后，肿瘤有明显缩小。结论骨pPNETs以溶骨性骨质破坏伴明显的软组织肿块、无骨膜反应为主要表现，缺乏特征性，但影像学检查有助于了解病变的范围、治疗措施的制定和治疗效果的评价。     

Computed tomography and magnetic resonance imaging findings of peripheral primitive neuroectodermal tumors of the head and neck

Purpose

We aimed to analyze the computed tomography (CT) and magnetic resonance imaging (MRI) findings of peripheral primitive neuroectodermal tumor (pPNET) of the head and neck.

Methods

Eight patients with pPNET of the head and neck confirmed by histopathological examination were analyzed retrospectively.

Results

The average patient age was 8 years. The tumor location in the 8 patients was as follows: maxillofacial region (right, 2; left, 1), left maxillary sinus (1), right masticator space (1), left carotid space (1), right infratemporal fossa (1), and left parotid gland (1). All 5 patients who underwent CT demonstrated ill-defined soft masses and no calcification. Three patients with tumors in the maxillofacial region showed homogeneous small masses and a mild enhancement. The patient with left maxillary sinus tumor showed a heterogeneous mass with patchy, necrotic foci and mild heterogeneous enhancement. The patient with right masticator space tumor showed a heterogeneous mass, and marked heterogeneous enhancement. The T1-weighted images of the patients with right infratemporal fossa, left carotid space, and left parotid gland tumors were isointense. The T2-weighted images were heterogeneous and mildly hyperintense in 2 patients and hyperintense in 1 patient. Heterogeneous intermediate enhancement was demonstrated in 2 patients and mild ring enhancement in 1 patient.

Conclusion

The imaging features of pPNET of the head and neck are non-specific. An ill-defined, aggressive mass and variable enhancement on CT and MR images may suggest the diagnosis of pPNET. Peripheral PNET should be included in the differential diagnosis of children and adolescents’ regional tumors.