腮腺基底细胞腺瘤的CT与MRI表现

目的:探讨腮腺基底细胞腺瘤(BCA)的CT和MRI表现。方法:回顾性分析10例腮腺BCA的CT和MRI表现。10例中男3例,女7例;右侧腮腺4例,左侧6例。结果:10例肿瘤均为单发,肿瘤最长径平均为2.4cm。10例肿瘤中不规则形或深分叶状2例,圆形或类圆形8例;边缘均光滑清楚。MRI检查2例,表现为长T1、短T2信号实性肿块,伴稍低信号包膜,增强扫描后病灶呈均匀明显强化。CT检查8例:6例呈实性,2例呈囊实性、内有大片液化囊变,实性部分明显强化。结论:腮腺BCA的CT和MRI表现有一定特征,结合临床,有助于本病的诊断和鉴别诊断。     

Basal cell adenoma of the parotid gland: MR imaging findings with pathologic correlation

BACKGROUND AND PURPOSE: Basal cell adenomas (BCAs) are rare tumors of the parotid gland. Only a few case reports describing MR imaging features of BCA have been published. The aim of this study was to describe and characterize the MR findings of BCAs of the parotid gland. MATERIALS AND METHODS: We retrospectively reviewed MR images of BCA with pathologic correlation in 8 cases (2 men and 6 women; age range, 52-82 years) collected between January 1992 and August 2004 from our pathologic data base. All MR images were retrospectively evaluated with respect to the marginal morphology, signal intensity (SI), and enhancement behavior by 2 experienced radiologists. RESULTS: On pathologic examination, 5 tumors were solid type, 2 were trabecular type, and 1 was membranous type. All of the tumors were well circumscribed with smooth contours. Cystic changes were seen in 4 cases. On T1-weighted images (T1WI), 7 tumors showed homogeneously low SI equal to muscle and one showed heterogeneously low SI. On T2-weighted images (T2WI), all of them showed slightly lower SI than that of surrounding parotid tissue. On gadolinium-enhanced T1WI, 6 tumors demonstrated moderate enhancement and one demonstrated strong enhancement (membranous type). Dynamic studies were performed in 4 cases. All showed rapid and prolonged enhancement. CONCLUSION: MR imaging findings of BCA were well-defined and smooth marginal morphologies, relatively low SI on both T11W and T2WI, and rapid and prolonged enhancement on dynamic study. Although BCAs are rare, they should be suspected when a tumor shows all of the characteristics noted here.     

Castleman disease of the parotid gland: MR imaging findings with pathologic correlation

A case of a hyaline-vascular type of Castleman disease originating in the parotid gland in which MR-pathologic correlation was obtained was presented. T1- and T2-weighted MR images showed a well-circumscribed 6 cm mass of intermediate signal intensity with hypointense branching structures within the mass. Gadolinium-enhanced dynamic MR imaging demonstrated a marked homogeneous enhancement of the mass with a peak enhancement at 60 s after intravenous gadolinium injection, whereas the branching structures showed a delayed enhancement to the degree of the mass at equilibrium phase. MR-pathologic correlation revealed that the branching structures corresponded to thick fibrotic bundles in the mass. A homogeneously enhancing well-circumscribed parotid mass with hypointense branching structures may indicate Castleman disease.     

Diffuse hepatic angiosarcoma with a portal venous supply mimicking hemangiomatosis

We report a case of diffuse hepatic angiosarcoma. Dynamic computed tomography (CT) showed gradual contrast enhancement and homogeneity in the late phase. The tumor was homogeneously hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging, mimicking hemangiomatosis. An angiogram demonstrated intrahepatic arterial encasement, which suggested malignancy. The portal venous supply to the tumor was demonstrated by CT during arterioportography. This probably reflected the continuous infiltration of atypical cells into the dilating sinusoids and may also suggest malignancy.     

Castleman's disease in the retropharyngeal space: CT and MR imaging findings

We report CT and MR imaging findings in a case of Castleman's disease involving the retropharyngeal space in a middle-aged woman. On CT scans, a well-marginated, homogeneous, and densely enhancing mass was detected in the right retropharyngeal space. The mass was isointense to the muscle on T1-weighted MR images, hyperintense to the muscle on T2-weighted MR images, and showed homogeneous, strong enhancement on contrast-enhanced T1-weighted MR images. The linear hypointense signal in an arborizing pattern was observed within the mass on all pulse sequences.     

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.     

腮腺腺淋巴瘤的CT、MRI诊断及鉴别诊断

目的探讨腮腺腺淋巴瘤的CT、MRI表现特点,提高对本病的诊断及鉴别诊断水平。方法回顾性分析经手术病理证实的24例腮腺腺淋巴瘤患者的临床及CT、MRI表现。结果 24例腮腺腺淋巴瘤共发现37个肿瘤(单侧单发13例,单侧多发6例.双侧多发5例),其中30个(81.1%)位于腮腺浅叶和后下象限。肿瘤一般呈圆形、椭圆形或分叶状软组织肿块,边缘光整,密度均匀或不均匀,囊变区呈类圆形液性密度灶;T1WI呈低信号,T2WI及压脂T2WI呈低、高混杂信号,囊变区呈明显的T1WI低信号T2WI高信号。增强后表现为早期轻中度强化。结论腮腺腺淋巴瘤有一定的临床和影像特点.根据其发病年龄、性别、部位及影像学表现,有助于该病的诊断和鉴别诊断。     

Supratentorial Gangliocytoma Mimicking Extra-axial Tumor: A Report of Two Cases

We report two cases of supratentorial gangliocytomas mimicking an extra-axial tumor. MR imaging indicated that the tumors were extra-axial, and meningiomas were thus initially diagnosed. Relative to gray matter, the tumors were hypointense on T1-weighted images and hyperintense on T2-weighted images. On contrast-enhanced T1-weighted images, homogeneous enhancement was observed, while CT scanning revealed calcification in one of the two cases.     

MR Imaging of Solitary Fibrous Tumors in the Head and Neck

Objective

Solitary fibrous tumor (SFT) is a very rare tumor. The purpose of this study is to determine the MR imaging features of SFT in the intracranial and extracranial head and neck regions.

Materials and Methods

We retrospectively reviewed six MR images and two CT images of six histologically proven cases of SFT that occurred in four men and two women, and their ages ranged from 46 to 59 years. These imaging findings were correlated with the microscopic findings of their surgical specimens.

Results

Six SFTs arose in the meninges (the petrous ridge and the pituitary fossa), the parotid gland, the parapharyngeal space, the buccal space and the maxillary sinus. On the MR images, SFTs in the intracranial and extracranial head and neck regions were mostly isointense to the muscle on the T1-weighted images, they were hyperintense on the T2-weighted images and they all had intense enhancement. On the T1- and T2-weighted images, hypointense lines were observed within in five SFTs. On the CT images, the SFTs were hypodense to the muscle on the unenhanced images and they were heterogeneously enhanced on the contrast-enhanced images. An exceptional case of pituitary SFT was hypointense on the T2-weighted images and it was hyperdense on the unenhanced CT images, which correlated with the increased collagenous component and the cellular compactness.

Conclusion

The imaging features of SFT are nonspecific; however, SFT should be included in the differential diagnosis of masses involving the intracranial and extracranial head and neck regions.     

Basal cell adenoma in the parapharyngeal space: MR findings

We report MR findings of a case of basal cell adenoma arising in the parapharyngeal space. On MR imaging, the mass was a well-circumscribed cystic and solid tumor with a thin fibrous capsule and intratumoral hemorrhage. It was confined to the parapharyngeal space, separating from the deep lobe of the parotid gland. The solid portion of the tumor was slightly hypointense/hyperintense to the muscle on T1-/T2-weighted images and was relatively well enhanced on Gd-enhanced T1-weighted images. The cystic contents of the mass were hyperintense on both T1- and T2-weighted images and were proven to be a hemorrhage.     

CT and MRI findings of carcinoma showing thymus-like differentiation

Carcinoma showing thymus-like differentiation (CASTLE) is a rare tumor that occurs in the soft tissue of the neck or in the thyroid gland. We report a case of CASTLE in a 54-year-old man presenting with hoarseness. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a mass enclosing the right carotid artery with the shape of lobulation and invasion to the trachea. The mass was hypointense on T1-weighted imaging and, on T2-weighted imaging, showed a hyperintense periphery with isointense center relative to muscle. In dynamic MRI, the mass revealed gradual but slight heterogeneous enhancement from the periphery. Diagnosis was confirmed by histopathology.     

Solitary fibrous tumor of the parapharyngeal space: MR imaging findings

We report the MR imaging findings of a solitary fibrous tumor involving the parapharyngeal space. The tumor was a well-circumscribed solid mass with a lobulated contour. It had the same signal intensity as the muscle on T1-weighted MR images, heterogeneously high signal intensity on T2-weighted images, and homogeneous strong enhancement after the administration of contrast material. It mimicked a tumor originating from the deep lobe of the parotid gland.     

婴儿型肝脏血管内皮瘤的影像诊断

目的 总结婴儿型肝脏血管内皮细胞瘤的临床与影像学表现. 资料与方法 回顾性分析6例婴儿型肝脏血管内皮细胞瘤的临床与影像学表现,所有的病例均经穿刺病理证实.5例行CT扫描,1例行MRI平扫. 结果 CT平扫表现为肝内低密度灶,1例出现钙化,增强扫描动脉期肿瘤均呈不均匀环形强化,4例中央部位出现结节样强化;门静脉期全部病例由周边向中心强化,强化范围扩大;延迟期病灶密度稍高于或等于正常肝实质.1例MR表现为肝内多发结节,T1WI低信号,T2WI高信号,增强扫描动脉期部分结节呈环形强化,部分结节呈全瘤均匀强化,延迟期全部结节呈全瘤强化. 结论 本病的CT与MRI表现有一定的特征性,有助于诊断本病.     

Irradiated carcinoma of the tongue: correlation of MR imaging findings with pathology

OBJECTIVE: MR imaging was prospectively correlated with pathologic findings to study whether MR imaging can differentiate viable from nonviable tumor tissue in the irradiated carcinoma of the tongue. SUBJECTS AND METHODS: MR examinations were performed after radiation therapy in 21 patients with carcinoma of the tongue. All patients underwent either a total glossectomy or hemiglossectomy after radiation therapy. Specimens were examined microscopically. Radiation changes were histologically graded into four groups (I, minimal cellular changes; II, presence of cellular changes and partial destruction of the tumor; III, only nonviable tumor cells; IV, no tumor cells). MR examinations included T2-weighted imaging, unenhanced T1-weighted imaging, dynamic contrast-enhanced imaging, and contrast-enhanced T1-weighted imaging. RESULTS: On unenhanced T1-weighted images, the lesion was hypointense, except for two patients with histologic grade III. On T2-weighted images, the lesion appeared hyperintense in 12 of 14 patients with viable tumor cells (grades I and II); however, the lesion was hypointense in four, and isointense in two of seven patients with nonviable tumor cells (grades III or IV). Contrast-enhanced T1-weighted images showed that the degree of contrast enhancement of the lesion was equal to or lower than that of a normal salivary gland in 18 of 21 patients. For the time of maximal enhancement of the lesion on dynamic imaging, there was no substantial difference between viable (grades I and II) and nonviable (grades III and IV) tumor tissue. CONCLUSION: The present study shows that T2-weighted imaging is feasible for differentiating viable from nonviable tumor tissue in irradiated carcinoma of the tongue.     

Low-grade fibromyxoid sarcoma of the small bowel mesentery: computed tomography and magnetic resonance imaging findings

Low-grade fibromyxoid sarcoma (LGFMS) is a rare tumor that commonly arises in the lower extremities but rarely in the mesentery. We report computed tomography (CT) and magnetic resonance imaging (MRI) findings of LGFMS of the small bowel mesentery. On CT, the mass was composed of two components. One component, on its right side, appeared to have isointense attenuation relative to muscle, whereas the other component, on its left side, appeared to have low attenuation. On MRI the mass on the right side showed hypointensity similar to muscle on both T1-and T2-weighted images as well as mostly slight enhancement on contrast-enhanced T1-weighted images. On the other hand, the mass on the left side showed relative hypointensity on T1-weighted images and hyperintensity on T2-weighted images as well as intense enhancement on contrast-enhanced T1-weighted images, suggesting that the tumor contained myxoid tissue. The myxoid area of LGFMS may have a tendency to reveal intense enhancement on contrast-enhanced images.     

Basal cell adenoma in the parotid gland: CT and MR findings

Basal cell adenoma is a rare benign salivary gland epithelial tumor, usually involving the parotid gland. We report CT and MR findings of three cases with basal cell adenoma occurring in the parotid gland. The three cases presented here demonstrate a well-circumscribed tumor, which showed a cystic and solid, or the pure solid mass. They were well enhanced after contrast matter injection. The solid portion of the mass was isoattenuated at CT, with intermediate signal intensity on T1- and T2-weighted MR images. Its cystic portion was hyperintense on both T1- and T2-weighted MR images. It had a hypointense rim on T2-weighted image.     

头颈部孤立性纤维瘤的影像学表现

目的：探讨头颈部孤立性纤维瘤(SFT)的影像特征,提高对该病的认识。方法回顾性分析10例经手术病理证实的头颈部 SFT 患者的 CT 和 MR 表现。10例均行 CT 平扫及双期增强扫描、2例行 MR 检查。结果10例病灶均表现为孤立的肿块,最大径20~115 mm,中位最大径约35.5 mm。肿瘤发生于眼眶2例、鼻腔鼻窦4例,腮腺、面颊、锁骨上区及枕部各1例。病变边界清楚8例、模糊2例,呈椭圆形7例,分叶状3例。CT 平扫呈等或稍低密度,其中4例密度均匀,6例密度不均匀(2例见多发囊变区,1例见结节状钙化灶)。增强后9例呈明显均匀(n=3)或不均匀(n=6)强化,1例呈轻度均匀强化。CT 双期增强强化模式包括快速强化缓慢廓清8例、快速强化快速廓清1例和延迟强化1例。与脑实质相比,T1 WI 呈均匀等信号1例,等、低混杂信号1例;T2 WI 呈均匀等信号1例,等、高混杂信号(多发囊变)1例;增强后分别呈均匀和不均匀显著强化。结论头颈部不均匀的富血供肿瘤要考虑到 SFT 的可能。瘤体 T2 WI 与脑实质相比呈等或稍低信号,CT 增强扫描明显强化,双期增强呈快速强化缓慢廓清的强化模式可能是有诊断价值的影像特点。     

Infantile fibromatosis of the neck with intracranial involvement: MR and CT findings.

CT and MR imaging studies were performed in a 3-year-old boy with infantile fibromatosis arising from the infratemporal fossa and extending into the middle cranial fossa. On CT scans, the lesion was hyperattenuating (44-49 Hounsfield units [HU]), enhancing significantly after application of contrast material (63-66 HU). The MR images showed a multilobulated lesion of heterogeneous signal intensity. The tumor was markedly hypointense on T2-weighted images and slightly hypointense on T1-weighted images relative to brain tissue, iso- or slightly hyperintense relative to tongue muscle on both T2- and T1-weighted images, and enhanced strongly after administration of gadopentetate dimeglumine.     

Polyostotische Knochenver?nderungen mit assoziierten intramuskul?ren Weichteiltumoren

A 40-year-old female patient presented with progressive painful soft tissue lesions in the left upper arm. Conventional radiography showed multicystic bone tumors of the left humerus, radius and ulna. The computed tomography (CT) scan showed no paraosteal spread. Magnetic resonance imaging (MRI) detected intramuscular tumors in the deltoid muscle, biceps humeri muscle and triceps humeri muscle which were T2-weighted hyperintense and T1-weighted hypointense. Postcontrast images showed a marginal enhancement. The findings corresponded to the rare Mazabraud’s syndrome in which polyostotic fibrous dysplasia is associated with intramuscular myxomas.     

Kimura病的CT、MRI表现

目的 探讨Kimura病的CT、MRI表现,提高该病的术前诊断水平.方法 回顾性分析11例经病理证实的Kimura病患者的临床特征、CT及MRI表现.11例Kimura病患者发生于(或累及)腮腺区7例,颌面部2例,硬腭1例,腹股沟1例(其中3例为异位复发,2例为原位复发).均表现为无痛性肿物,平均病程2年以上;嗜酸性粒细胞均明显增高.结果 CT和MRI表现:5例单发结节,6例多发结节;最小者约6 mm×3 mm,最大者约60 mm ×34 mm;较大结节边界不清楚,较小者边界清楚,邻近脂肪间隙内见条索影浸润,10例颌面部病灶均位于浅筋膜下;CT显示9例密度均匀,稍低于肌肉密度;3例在MR T2WI上呈稍高信号,在T1 WI上呈等或稍低信号;11例肿块呈中度至重度、均匀或不均匀强化;9例肿块(8例颌面部、1例腹股沟)伴有同侧(或双侧)引流区淋巴结肿大,边界清楚,无坏死,无融合,强化明显.结论 Kimura病具有一定的临床和影像特征,结合实验室检查,可以进行正确诊断.