纵隔原发性恶性生殖细胞瘤的CT和MRI表现

目的：探讨纵隔原发性恶性生殖细胞瘤的CT和MRI影像表现特点,以提高对本病的认识和诊断水平.方法：经病理证实的纵隔原发性恶性生殖细胞瘤13例,总结和分析其临床、CT及MRI表现.观察项目包括病灶数目、部位、大小,内部结构、边界及与周围结构的关系等.结果：13例均为青壮年患者,单发病灶,位于前中上纵隔,病灶最大截面直径约63 mm.CT表现为病灶内密度不均匀,可见片状坏死,增强后呈明显不均匀轻度强化.4例行MRI扫描,T1WI示病灶呈等信号或稍低信号、T2WI呈等信号或稍高信号,肿瘤内信号不均匀,12例伴有出血、坏死灶,增强扫描呈不均匀轻度～中度强化.病灶边界欠清,其中11例病变与纵隔血管间脂肪间隙消失,10例可见病变周围结构受侵犯,9例血管受侵,3例合并上腔静脉闭塞,6例累及心包,3例侵犯前胸壁及胸骨.结论：纵隔原发性恶性生殖细胞瘤CT和MRI表现具有恶性肿瘤侵袭性的特征,但影像表现缺乏特异性;结合临床及实验室检查有助于恶性生殖细胞瘤的诊断.     

CT findings of primary non-teratomatous germ cell tumors of the mediastinum--a report of 15 cases

Objective

To analyze computed tomography (CT) features of primary non-teratomatous germ cell tumors of the mediastinum and to improve the diagnostic efficacy of CT for such tumor.

Methods

Fifteen patients with primary non-teratomatous germ cell tumors of the mediastinum, proven pathologically, were enrolled. All patients underwent non-enhanced and contrast-enhanced CT examinations. The CT features, including location, size, shape, edge, CT attenuation, involvement of adjacent structure and local or distant metastasis of each lesion were retrospectively analyzed.

Results

Each case showed single mass, a total of 15 masses. 11 masses arose within the left anterosuperior mediastinum and 4 masses arose within the right anterosuperior mediastinum. 10 masses appeared lobulated and ill-circumscribed, and 5 masses appeared rounded or oval and well-circumscribed. The maximal diameter of all the masses ranged from 5 cm to 16 cm (mean, 11 cm). 12 masses revealed heterogeneous attenuation on non-enhanced CT images with patchy low-attenuation foci and stippled calcification, and showed moderately heterogeneous enhancement after contrast administration. 3 masses of the patients with seminoma revealed homogeneous attenuation on non-enhanced CT images and showed lightly homogeneous enhancement after contrast administration. Pericardial effusion, pleural effusion and involvement of adjacent vascular structures were observed in 6, 5 and 10 cases, respectively. Pulmonary metastasis were observed in 3 cases.

Conclusions

The characteristic CT findings of primary non-teratomatous germ cell tumors of the mediastinum include bulky, ill-circumscribed, lobulated masses, heterogeneous attenuation with low-attenuation foci and calcification on non-enhanced CT images and heterogeneous enhancement after contrast administration. Seminomas may show homogeneous attenuation and homogeneous enhancement after contrast administration. The tumor is apt to involve pericardium, pleura and adjacent vascular structure and develop distant metastasis. Primary non-teratomatous germ cell tumors should be considered when anterosuperior mediastinal masses are detected with these findings, especially in young males.     

纵隔生殖细胞源性肿瘤的CT诊断和鉴别诊断(附32例报告)

目的总结纵隔生殖细胞源性肿瘤的CT表现及良、恶性的鉴别要点。方法回顾性分析32例经手术病理证实的纵隔生殖细胞源性肿瘤。结果32例中,良性生殖细胞源性肿瘤26例,其中囊性肿块10例,实性肿块9例,囊实性肿块7例;恶性生殖细胞源性肿瘤6例,其中精原细胞瘤、内胚窦(卵黄囊)瘤及胚胎细胞癌各1例和恶性畸胎瘤3例。典型的良性畸胎类肿瘤显示水样至软组织密度肿块,边缘清晰,其内有脂肪或钙化等,推移压迫周围组织,恶性肿瘤具有边缘分叶状或不规则,与周围组织脂肪间隙消失并侵犯相邻器官的征象。结论CT对纵隔良性生殖细胞源性肿瘤能准确作出诊断,纵隔恶性生殖细胞源性肿瘤难以与纵隔其它恶性肿瘤区分。     

混合性生殖细胞瘤的64层螺旋CT诊断及病理表现

目的:探讨64层螺旋CT对混合性生殖细胞瘤的诊断价值。方法:回顾性分析7例经病理证实的混合性生殖细胞瘤的CT平扫及两期增强表现、病理标本及切片特征。结果:7例病灶3例位于卵巢,3例位于前纵隔,1例位于睾丸;其中3例边界清楚;各病灶密度不均匀,内见囊变、坏死区,1例可见脂肪及钙化;增强扫描静脉期较动脉期强化明显,均呈不均匀强化。病理结果2例卵黄囊瘤与成熟畸胎瘤混合型,2例卵黄囊瘤与未成熟畸胎瘤混合型,1例卵黄囊瘤、胚胎性癌、畸胎瘤混合型,1例绒癌与无性细胞癌混合型,1例精原细胞瘤、胚胎性癌、滋养细胞成分混合型。结论:64层螺旋CT对混合性生殖细胞瘤的诊断虽无特异性,但在一定程度上为肿瘤良恶性判断、临床分期提供十分重要的依据。     

Computed tomography of anterior mediastinal tumors. Differentiation between thymoma and germ cell tumor

Computed tomographic (CT) features in 10 patients with germ cell tumor of the mediastinum and 15 with thymoma were compared with surgically resected specimens. The CT findings of the internal structure of tumors were the most important factor for specific diagnosis. Germ cell tumors showed a round mass without distinct lobulation, frequently with calcification appearing as a globular shape, and especially in benign tumors as an arched shape along the wall. Homogeneous low density masses (near-water) with a thick wall were benign and non-homogeneous density masses (a mixture of near-water and soft tissue) were malignant. Thymoma usually showed a solid mass with lobulation and sometimes had an eggshell type of calcification in the tumor. Therefore, CT is of importance in the diagnosis of anterior mediastinal masses.     

From the archives of the AFIP. Mediastinal germ cell tumors: radiologic and pathologic correlation.

Germ cell tumors occur most frequently in the gonad but can rarely occur in extragonadal locations, usually in or near the midline. The most common extragonadal site of primary germ cell tumors is the anterior mediastinum. The most common histologic type of mediastinal germ cell tumor is mature teratoma, which is typically asymptomatic and incidentally discovered. Radiographically, these tumors appear as rounded, often lobulated masses; calcification may be seen. Imaging studies of mature teratoma frequently demonstrate cystic components and may demonstrate fat or calcium. Malignant germ cell tumors usually occur as large masses in symptomatic young male patients. Seminomas are typically of homogeneous soft-tissue attenuation, and nonseminomatous malignant germ cell tumors are typically of heterogeneous attenuation on computed tomographic scans. Therapy varies according to cell type and may include surgery, radiation therapy, or chemotherapy. Prognosis is excellent for patients with mature teratoma, good for patients with pure seminoma, and poor for patients with nonseminomatous malignant germ cell tumors and mixed germ cell tumors.     

Computed tomography for parathyroid localization

Computed tomography (CT) of the neck and mediastinum was performed in 10 patients with primary hyperparathyroidism. Nine had undergone previous surgery and were considered localization problems. Of four subsequently proven cervical adenomas, only one unusually large 19-g adenoma was visualized by CT. However, of two subsequently proven anterior mediastinal adenomas, CT scanning was positive in both; a single posterior mediastinal adenoma was not demonstrated. Of the remaining three patients, one was not operated on; in two others no adenoma was found at surgery. CT scanning is recommended prior to neck surgery in all patients with primary hyperparathyroidism to identify adenomas in the anterior mediastinum.     

Endodermal sinus (yolk sac) tumors of the anterior mediastinum

Seven cases of endodermal sinus tumor (yolk sac tumor) primary in the anterior mediastinum are added to the literature bringing to 21 the number of reported cases. This germ cell tumor should be included in the differential diagnosis of anterior mediastinal tumors. It has occurred in males 13--49 years old who are often systemically ill. Since this tumor almost always produces elevated levels of serum alpha-fetoprotein, a strong presumptive diagnosis is possible prior to biopsy. The prognosis is poor. The two disease-free survivors of the 21 reported cases were both treated with a combination of excision and chemotherapy.     

Posterior mediastinal teratoma presenting as an abdominal mass in a child: A case report

We report the case of a 2.5-year-old child admitted for abdominal distension, whose imaging revealed a large posterior mediastinal cystic mass, with a tissue component, a calcification, and a minimal fat component. The ultrasound- guided biopsy led to the diagnosis of a benign extragonadal germ cell tumor, also called mature teratoma or dermoid cyst, whose mediastinal localization is rare, often localized in the anterior mediastinum, and rarely in the posterior mediastinum. The mainstay of treatment is complete surgical excision.     

Primary mediastinal endodermal sinus tumors: CT evaluation

Five patients with primary mediastinal endodermal sinus tumor have been evaluated by computed tomography (CT). The tumors were all located in the anterior mediastinum. Prechemotherapy CT demonstrated large, irregularly enhancing inhomogeneous masses without fat components. Calcification was visualized in two tumors. Some parts of the pleura-lung interface were irregular in four cases. Obliteration of fat planes to pericardium and chest wall was evident in all cases, and there was infiltration of intercostal muscles in four. Postchemotherapy CT in two patients who responded to chemotherapy showed either newly developed cystic lesions or cystic change of the original mediastinal mass. The cystic masses had more regular borders, a homogeneous hypodense center, and a smooth peripheral rim of contrast-enhancing tissue.     

卵巢生殖细胞肿瘤的CT诊断

目的探讨卵巢生殖细胞肿瘤的CT表现特点.方法回顾性分析经手术病理证实的37例46个卵巢生殖细胞肿瘤的CT资料,结合病理讨论其CT表现特点.结果本组卵巢生殖细胞肿瘤中,畸胎瘤43个,内胚窦瘤2个,混合性生殖细胞瘤1个.对卵巢畸胎瘤,CT和B超的敏感性均为100%,特异性分别为93.02%和58.14%.30例38个成熟囊性畸胎瘤,CT明确诊断27例35个,均含有脂肪密度区,5个见脂液平面,11个有浮球征,16个有钙化或牙齿状影.5个未成熟畸胎瘤呈囊性或实性为主肿块,肿块内均见多发斑点状钙化和少许小片状脂肪密度影,其中1例实性成分内见盘曲的带状略低密度影.内胚窦瘤呈囊性1例,呈实性为主1例,实性肿块内见较大的不规则低密度坏死区.混合性生殖细胞瘤呈实质性,不规则形.结论卵巢畸胎瘤和内胚窦瘤的CT表现具有各自的特点,尤其是畸胎瘤,具有特征性表现,与B超相比,CT是更好的检查方法.     

纵隔内胚窦瘤的MSCT表现及诊断价值

目的探讨纵隔内胚窦瘤(mediastinal endodermal sinus tumor,MEST)的多层螺旋CT(MSCT)表现,提高临床诊断水平。方法回顾性分析7例病理证实的纵隔内胚窦瘤的MSCT表现。结果 7例病例均位于前纵隔,其中前上纵隔4例,前中上纵隔3例;CT平扫显示肿块均为实性软组织肿块,边界不清;6例密度不均匀,5例肿块内部可见坏死囊变,2例可见不规则钙化;增强扫描肿块中度～高度不均匀强化;1例较大肿块内可见强化血管。结论纵隔内胚窦瘤CT表现具有一定的特征性,MSCT图像后处理有利于病变细微结构的显示,根据CT表现可以提示诊断并帮助确定手术方案和推测预后,但确诊需依靠病理学。     

Primary Malignant Melanoma of the Mediastinum: Radiologic and Pathologic Correlation in Two Case

Primary malignant melanoma of the anterior mediastinum is extremely rare, accounting for 0.1-0.5% of all primary malignant neoplasms. These tumors may be mistakenly diagnosed as lymphomas, thymic carcinomas and malignant germ-cell tumors of the mediastinum. We describe two cases of primary malignant melanomas of the anterior mediastinum and report their CT and pathology findings.     

CT in primary malignant germ cell tumors of the retroperitoneum.

Malignant germ cell tumors may exist as a primary entity in the retroperitoneum. In a CT study of 14 males with this condition (2 seminomas and 12 non-seminomatous tumors) all masses were large, lobulated and of mixed density. Fat plane obliteration against adjacent structures was frequent. The aorta was embedded in 9 patients and the inferior vena cava was affected in 7, 2 of whom had signs of compromised caval blood flow. Distant metastases were found in the lungs (7 patients), liver (n=4), posterior mediastinum (n=3), and in brain and supraclavicular lymph nodes in one patient each. Serum biomarkers were elevated in 11 patients. An extragonadal germ cell tumor should be considered when CT of the abdomen reveals a large retroperitoneal mass with mixed density.     

18F-FDG PET/CT与增强CT在成人原发前纵隔恶性肿瘤中的诊断价值

目的 探讨18F-氟脱氧葡萄糖（FDG） PET/CT与增强CT在成人原发前纵隔恶性肿瘤中的诊断价值,以提高对该部位病变的诊断水平。 方法 回顾性分析2016年6月至2019年5月在湖北文理学院附属医院（襄阳市中心医院）经病理证实的成人原发前纵隔肿瘤患者80例（恶性肿瘤35例、良性肿瘤45例）,其中,男性46例、女性34例,年龄20~80（45.5±10.2）岁。所有患者均行全身18F-FDG PET/CT及胸部CT平扫+增强扫描,2种检查的间隔时间在2周内。分别计算并采用χ2检验比较18F-FDG PET/CT与增强CT扫描的诊断灵敏度、特异度和准确率,采用χ2检验比较2种检查方法对不同类型恶性肿瘤的诊断效能。 结果 35例恶性肿瘤中胸腺癌15例,淋巴瘤10例,恶性生殖细胞瘤7例,神经内分泌癌、恶性黑色素瘤及滑膜肉瘤各1例。18F-FDG PET/CT诊断成人原发前纵隔恶性肿瘤的灵敏度[97.1%（34/35）]、特异度[93.3%（42/45）]及准确率[95.0%（76/80）]均高于增强CT[71.4%（25/35）、77.8%（35/45）、75.0%（60/80）],且差异有统计学意义（χ2=8.612、4.357、12.471,均P<0.05）;18F-FDG PET/CT对胸腺癌、淋巴瘤及恶性生殖细胞瘤诊断的准确率[93.3%（14/15）、100.0%（10/10）、85.7%（6/7）]均高于增强CT[60.0%（9/15）、50.0%（5/10）、28.6%（2/7）],且差异有统计学意义（χ2=4.503、6.333、4.333,均P<0.05）。 结论 18F-FDG PET/CT对成人原发前纵隔恶性肿瘤具有重要的诊断价值,其诊断效能优于增强CT,可作为该病主要的检查方法。     

原发性前纵隔肿瘤73例CT分析

目的 探讨原发性前纵隔肿瘤的CT特征性表现及鉴别诊断.方法 回顾性分析73例经病理证实的常见前纵隔肿瘤(37例胸腺瘤,17例生殖细胞肿瘤,19例淋巴瘤)的患者CT表现,包括肿瘤有无脂肪密度、囊变、钙化、强化、纵隔侵犯和淋巴结肿大.结果 58.8％ (10/17)的生殖细胞瘤发现脂肪密度,出现率显著高于其他前纵隔肿瘤(P＜0.001).73.7％(14/19)淋巴瘤发现纵隔肿大淋巴结,显著高于其他前纵隔肿瘤(P＜0.001).其他CT征像在这些前纵隔肿瘤中无显著性差异(P＞0.05).结论 前纵隔肿瘤CT扫描发现脂肪密度和纵隔淋巴结肿大为特异性征像,脂肪密度的出现高度提示生殖细胞肿瘤,而前纵隔肿瘤伴有淋巴结肿大高度提示淋巴瘤.     

胸腺内胚窦瘤的CT诊断

目的:探讨胸腺内胚窦瘤的CT表现。方法:回顾性分析8例经手术病理证实的胸腺内胚窦瘤患者的CT表现。主要观察内容包括病变位置、大小、内部结构、边界及与周围结构的关系等。结果:8例中病灶位于前上纵隔5例,前中纵隔2例,前下纵隔1例。最大截面直径<3cm者2例,3~5cm者2例,>5cm者4例。CT平扫示病灶内密度不均匀,可见片状坏死,增强后呈明显不均匀强化。所有病灶边界不清,其中2例病变与纵隔血管分界不清,脂肪间隙消失;1例病变推移纵隔血管,但血管没有明显变形;5例可见病变周围结构受侵犯,3例为血管受侵,表现为血管变形,其内并见软组织密度影,1例病变侵及邻近肺组织,1例侵犯前胸壁及胸骨。结论:胸腺内胚窦瘤的CT表现具有恶性肿瘤的特点但缺乏特异性,确诊有赖于病理学检查。     

Primary malignant mediastinal germ cell tumours: a literature review and a study of 18 cases

From 1957 to 1992, 18 cases of primary mediastinal germ cell tumours were referred to the Peter MacCallum Cancer Institute (PMCI). Six were seminomas, six were mixed germ cell tumours, two were embryonal cell carcinomas, three were teratocarcinomas and one was labelled an 'anaplastic germ cell tumour'. Two of the 18 patients were female. For seminomas, surgical (and in one case chemotherapeutic) debulking, followed by radiotherapy produced the best results. Mediastinal doses ranged from 30 to 40 Gy. Local control was achieved in those patients receiving mediastinal radiotherapy. Four patients currently survive disease-free. The non-seminomatous germ cell tumours showed a significantly poorer survival, and only two of 12 patients remain alive in remission at 110 and 130 months after diagnosis. Survival has been updated as of November 1997. Attention is focused on the anterior position of the primary germ cell tumours in the mediastinum. A review of the literature up to and including 1997 is presented.     

肺-纵隔交界区肿瘤的多层螺旋CT征象分析

目的:探讨肺-纵隔交界区肿瘤的多层螺旋CT特征.方法:搜集经手术、活检病理证实的50例肺-纵隔交界区肿瘤,回顾性分析其多层螺旋CT平扫及增强扫描特征,选择分析对肺-纵隔交界区肿瘤定位定性诊断有价值的影像学征象.有价值的CT定位征象主要有:宏观征象:病灶中心位置;病灶与肺及纵隔交界面的夹角;纵隔内脂肪间隙及大血管形态的改变情况;病灶密度(钙化、脂肪等);胸膜增厚及移位情况;纵隔淋巴结肿大情况;胸腔积液;肺内纹理走行、病灶邻近肺野改变;增强扫描特征.细节征象:病灶与纵隔交界面特征;病灶与肺交界面特征.结果:肺癌22例,胸腺肿瘤20例,生殖细胞肿瘤3例,神经源性肿瘤5例,总的诊断符合率达到95%.结论:多层螺旋CT扫描及增强扫描特征,尤其是肿瘤与肺-纵隔分别的交界面情况,胸膜的移位情况,纵隔内大血管形态、位置改变等等,能对肺-纵隔交界区肿瘤作出正确的定位定性诊断.     

A case of Hurthle cell carcinoma in the superior mediastinum

This is a report for an unusual case of oxyphilic cell adenocarcinoma originating from anterior mediastinum in a 36-year-old male who complained of his neck lymphoadenopathy. 201Tl whole body scanning showed increased uptake of the left supraclavicular and upper mediastinal regions. There was no history of prior operation nor irradiation to the thyroid or neck region. Chest CT scanning also demonstrated the tumor in the superior mediastinum, but the mass has no increased 67Ga uptake. No tumor in the thyroid lobes was apparent on thyroid scintiscanning, ultrasonography and neck CT. The mediastinal tumor resection, the right and left thyroid lobectomy and the neck lymphonodectomy were completed. Serial sectioning of the resected thyroid lobes failed to show any tumorous tissue. The light microscopic features of a Hurthle-cell tumor arising in the mediastinal ectopic thyroid and diagnosed by neck lymph node biopsy were presented. The tumor was clinically malignant, having metastasized to the bone and the neck lymph nodes. Non surgical treatment including radioactive iodine (131I) therapy and combination chemotherapy were disappointing. The patient deteriorated progressively and died 16 months after thyroidectomy. We describe here an unusual case of a papillary growing and thyroglobulin producing tumor in the superior mediastinal region without evidence of a primary thyroid gland tumor.