Echography in the study of lipomas of superficial soft tissues]

High-resolution sonography (US) was used to evaluate 47 superficial soft tissue lipomas. Forty-one lesions were found in subcutaneous tissues and 6 in superficial muscles. The lipomas were classified by location, shape, echotexture, homogeneity and US beam attenuation values. Moreover, 21 lipomas underwent histology and histologic patterns were correlated with echogenicity. Most lesions were elongated and their greatest diameter was parallel to the skin. Eighty-four percent exhibited well-defined margins. Twenty-six percent of the lipomas were hypoechoic, 24% were isoechoic, 34% hyperechoic and 16% exhibited a mixed pattern. In 27% of cases, a hypoechoic capsule was present. Superficial soft tissue lipomas exhibit unsteady echotexture: most of them are hyperechoic. The correlation between echotexture and histology showed that no typical and steady patterns can be identified, since lipomas vary from a histologic point of view. The clinical diagnosis of superficial lipomas is based on clinical history and the palpation of a well-defined, mobile and soft superficial mass. When palpation is not diagnostic, US can be used to rule out a cyst. An elongated isoechoic or hyperechoic mass in the subcutaneous tissue should suggest a lipoma, whereas a hypoechoic mass is associated with a broader range of differential diagnoses, including malignant tumors. However, malignant masses are not likely to have an elongated or flattened shape. Even though tissue characterization is less specific with US than with CT and MRI, the former method is quick, easy and less expensive and, thanks to high-frequency transducers, is also well-suited to diagnose soft tissue lipomas.     

鼻腔副鼻窦恶性肿瘤的CT诊断

目的探讨鼻腔副鼻窦CT检查方法和肿瘤的形态、密度、窦壁骨质破坏、周围脂肪层侵犯、窦腔外软组织肿块等征象在鼻腔副鼻窦恶性肿瘤中的诊断作用.材料与方法逐项对比观察分析经病理证实的鼻腔副鼻窦恶性肿瘤32例和良性肿物139例的CT表现.结果CT冠状位扫描显示15例恶性肿瘤破坏25个窦腔骨壁,20例腔外软组织肿块累及23个相邻部位.轴位扫描发现骨壁受累12例,有20个侧壁骨质显示破坏,15个腔外肿块累及18个相邻结构.恶性组和良性组突出于窦腔外的软组织肿块分别为71.9%和5.0%、窦壁骨质侵蚀性破坏59.4%和14.4%、窦腔周围脂肪层的侵犯消失56.3%和13.7%,而软组织肿块形态不规则和密度不均匀,两组间无显著差异.结论鼻腔副鼻窦腔外软组织肿块、侵蚀性骨质破坏和窦壁周围脂肪层的侵犯消失,是诊断鼻腔副鼻窦恶性肿瘤的可靠征象.冠状扫描观察解剖内容和病变侵犯范围优于轴位扫描.     

Cross-sectional imaging of idiopathic solitary renal vein varix: report of two cases

Two cases of solitary renal vein varices are reported which presented as incidental findings on abdominal computed tomography (CT) and were initially thought to represent retroperitoneal lymph nodes. Contrast-enhanced CT, magnetic resonance imaging (MRI), and Doppler ultrasound (US), all demonstrated the vascular nature of these masses suggesting the correct diagnosis. When a rounded soft tissue density mass is seen on noncontrast-enhanced CT either in or contiguous to the renal hilum, a renal vein varix must be excluded. Doppler US, MRI, or dynamic contrast-enhanced CT should be done to exclude a renal varix as the cause.     

Hyperostotic esthesioneuroblastoma: CT and MR findings

Olfactory neuroblastoma is a malignant, slow growing, neurogenic tumor that originates in the olfactory mucosa of the upper nasal cavity. Its CT appearance, i.e., a soft tissue mass adherent to the cribriform plate usually with bone lysis, has been described. Two cases are presented in which this entity was associated with exuberant bony hyperostosis, a feature not previously reported. The differential diagnosis of nasoethmoid soft tissue masses with associated hyperostosis is reviewed.     

Benign lesions of the mandibular and maxillary region in children: characterization by CT and MRI.

The CT criteria for classifying lesions of the mandibular and maxillary regions in adults as benign or malignant are well recognized: irregular soft tissue margins and bone destruction. We reviewed the charts of 12 pediatric patients from 3 institutions to evaluate these criteria in children. These masses were evaluated by CT and/or MRI based solely on well-recognized and published criteria. The patients' ages ranged from 4 mo to 18 yr. The histological diagnoses were ameloblastoma (4), hemangioma (2), lymphangioma, desmoplastic fibroma, hemangiopericytoma, neurofibroma, fibrous dysplasia, and juvenile angiofibroma. All but one case was surgically proven. Among the 12 cases, 5 had bone destruction and 5 showed irregular soft tissue margins. Three cases satisfied both criteria. With well-recognized CT criteria (in adult patients), characterization of these processes led to an incorrect diagnosis of a malignant lesion in 8 of the 12 cases preoperatively. Therefore, CT and MR imaging should only be a guide to the planning and extent of surgical resection. Without clearly defined distal spread of the mass, the classification of these masses in children should be made with caution.     

Problematic renal masses in ultrasonography and computed tomography

The diagnosis of renal masses is based upon the contribution of ultrasonography (US) and computed tomography (CT), which enable the recognition of these lesions with high diagnostic accuracy. However, a number of diagnostic difficulties exist in the definition of the nature of the mass, both for cystic and solid lesions, and to a lesser extent in the identification of the mass. "Complicated" cystic masses, such as calcified cysts, hemorrhagic cysts, inflammatory cysts, abscesses, and cystic tumors may be difficult to diagnose with US and sometimes with CT. CT is helpful in most of these cases because it enables the evaluation of the calcifications and the density of the fluid content. CT is also helpful in cases of cystic tumors because it shows the enhancement of septae within the masses. Problems with solid masses are the identification of small renal tumors and the definition of the benign or malignant nature of the mass. Although both techniques enable the recognition of most tumors, even if small in diameter, they are still limited in defining the pathological structure of the tumor.     

Computer-aided diagnosis of peripheral soft tissue masses based on ultrasound imaging

Medical ultrasound (US) has been widely used for distinguishing benign from malignant peripheral soft tissue tumors. However, diagnosis by US is subjective and depends on the experience of the radiologists. The rarity of peripheral soft tissue tumors can make them easily neglected and this frequently leads to delayed diagnosis, which results in a much higher death rate than with other tumors. In this paper, we developed a computer-aided diagnosis (CAD) system to diagnose peripheral soft tissue masses on US images. We retrospectively evaluated 49 cases of pathologically proven peripheral soft tissue masses (32 benign, 17 malignant). The proposed CAD system includes three main procedures: image pre-processing and region-of-interest (ROI) segmentation, feature extraction and statistics-based discriminant analysis (DA). We developed a depth-normalization factor (DNF) to compensate for the influence of the depth setting on the apparent size of the ROI. After image pre-processing and normalization, five features, namely area (A), boundary transition ratio (T), circularity (C), high intensity spots (H) and uniformity (U), were extracted from the US images. A DA function was then employed to analyze these features. A CAD algorithm was then devised for differentiating benign from malignant masses. The CAD system achieved an accuracy of 87.8%, a sensitivity of 88.2%, a specificity of 87.5%, a positive predictive value (PPV) 78.9% and a negative predictive value (NPV) 93.3%. These results indicate that the CAD system is valuable as a means of providing a second diagnostic opinion when radiologists carry out peripheral soft tissue mass diagnosis.     

盆腔器官外软组织肿瘤的CT诊断

目的 探讨盆腔器官外软组织肿瘤的CT表现及其诊断价值。材料与方法 回顾性分析经手术病理证实的30例原发性盆腔器官外软组织良、恶性肿瘤的CT表现。其中间叶源性肿瘤15例,神经源性肿瘤8例,胚胎残余组织源性肿瘤5例,腹膜间皮细胞肿瘤2例。结果 原发于盆腔器官外软组织肿瘤较少见,CT表现为囊性肿块者均为良性,囊实性或实性者以恶性居多。虽然肿瘤来源于多种不同组织,但CT表现可各有其特征。结论 CT是诊断盆腔器官外肺瘤的重要影像学手段,能明确肿瘤范围以及肿瘤与周围组织的关系及其性质。     

Comparison of ultrasound,CT and MRI in the assessment of parotid masses

In order to compare the advantages and failings of the current imaging procedures used for the staging of parotid masses, 121 patients were investigated: 30 with ultrasound (US) and CT, 55 with US and MRI, and 36 with US, CT and MRI. The accuracy of the three imaging modalities was evaluated in detecting parotid lesions; in assessing their location (intra- or extraglandular) and nature (benign or malignant); and in defining their intraglandular extent (superficial or deep lobe) as well as their relationship with surrounding structures. The imaging findings were related to the cytohistological data from US-guided biopsy or from surgical resection. In the 36 patients studied with all three modalities the diagnostic accuracy (excluding double errors in the same patient) was 77.7% for US, 86.1% for CT and 94.4% for MRI. US was thus shown to be less accurate than CT or MRI, and MRI not significantly superior to CT. US with fine-needle aspiration cytology should be the first-line imaging technique; CT and MRI have to be- considered for lesions more than 3 cm in diameter or for masses arising in the deep lobe of the gland. The results of this series show that MRI provides better results than CT in displaying the relationship of the mass with contiguous structures. Correspondence to: L. Grazioli     

Ultrasound evaluation of soft tissue tumors.

Because of its availability, ultrasound should be the preferred initial modality for the evaluation of palpable superficial masses. Most ultrasound units are equipped with high frequency probes that allow superficial focalization. The differential diagnosis of soft tissue masses and the sonographic features of some benign and malignant soft tissue lesions are reviewed in this article. After an initial ultrasound evaluation confirming the presence of a tumor, the need for and the role of other imaging modalities can be determined. In selected cases ultrasound may obviate the need for further imaging. MRI and CT should be reserved for cases in which sonography fails to establish a specific diagnosis or to demonstrate the limits of the soft tissue mass.     

Soft Tissue Masses: The Underutilization of Sonography

For the evaluation of soft tissue masses, sonography (US) has proved to be very accurate in confirming the presence or absence of a lesion, with a very high negative predictive value. Many soft tissue masses result from trauma, inflammation, infection, or cystic changes and are not true neoplasms. In the proper clinical context, US can diagnose a muscular tear, hernia, myositis ossificans, or rhabdomyolysis. Retained foreign bodies are readily identified and localized with US. US differentiates between cellulitis and abscess and can diagnose masses resulting from tendinitis, tenosynovitis, or bursitis. It is the modality of choice for diagnosing cysts, including intact or ruptured Baker?s cysts and ganglion cysts in the distal extremities. Among benign neoplasms, lipomas and hemangiomas display a wide spectrum of echogenicity. US can diagnose nerve sheath tumors by demonstrating the connection between the mass and the normal nerve. Except for some well-differentiated liposarcomas, which may appear echogenic, the vast majority of malignant tumors in the soft tissues are hypoechoic. Real-time US is ideal for guiding large-core needle biopsy of soft tissue sarcomas. US is extremely sensitive in detecting early recurrences after surgical excision, which are readily confirmed by US-guided fine-needle aspiration. Any nonpalpable mass visualized by US can be conveniently localized pre- or intraoperatively with US guidance. Provided the examination is done by a well-trained operator using state-of-the-art equipment, the cost-effectiveness of US justifies its use as a first-line examination technique in many situations involving soft tissues, with magnetic resonance imaging being the problem-solving tool and staging procedure.     

骨和累及骨的外周性原始神经外胚层瘤的临床病理与影像学表现

目的探讨骨和累及骨的外周性原始神经外胚层瘤(pPNETs)的临床病理与影像学表现。资料与方法7例中6例有X线检查、2例有CT检查、4例有MR检查,分析其临床病理和影像学特点。结果6例X线片上均呈溶骨性骨质破坏,其中2例病变区存在骨质硬化,5例合并软组织肿块,均未见骨膜反应。2例CT像上均为溶骨性骨质破坏合并软组织肿块形成,软组织内未见钙化或骨化。MRI检查4例中有3例病变在T1WI呈中等信号,1例在T1WI呈低信号,4例在T2WI上均呈中、高信号,信号不均匀,增强扫描呈中度不均匀强化。4例均合并软组织肿块,其中3例有囊变坏死区。结论影像学上骨内病变呈溶骨性破坏,可伴有病变区的骨质硬化而一般无骨膜反应,并伴有较大软组织肿块者应考虑到pPNETs的可能。     

Sialography, echography and computerized tomography in the study of the parotid region

The diagnostic accuracy of sialography and ultrasonography (US) in the evaluation of parotid masses is evaluated. Furthermore the role of computed tomography (CT) in this pathology is discussed. In the personal experience US proved to be the best method in the recognition of a parotid tumor while sialography was superior in defining the intra or extraparotid site. The two investigations showed the same accuracy in the definition of benign or malignant nature of the mass. Therefore we consider US the only investigation in most instances; sialography could be performed when the site of the lesion is uncertain or an inflammatory lesion is suspected. CT is never the first investigation; its use is limited to a low number of cases, mainly for the evaluation of large masses and when the association US-sialography does not allow a sure diagnosis.     

Computed tomography of malignant lymphoma involving the skull

The CT findings in two patients with the unusual presentation of malignant lymphoma in the skull are described. The dominant CT findings were contrast enhanced large soft tissue masses without calcifications on both sides of the bone with very little or no changes in the bone itself. This characteristic CT appearance may be helpful to differentiate primary lymphoma of the skull from other bone tumors and osteomyelitis.     

CT窗口技术在诊断恶性骨肿瘤的应用

目的 研究不同窗宽窗位在恶性骨肿瘤诊断中的价值。材料与方法 分别在骨窗、软组织窗及中间窗下,对28例经手术病理证实的恶性骨肿瘤患者的CT表现进行回顾性统计学分析,比较不同窗口条件下CT对恶性骨肿瘤的诊断率。结果 骨窗能明确反映骨肿瘤骨密度异常的区域,而软组织窗及中间窗对显示肿瘤周围软组织和骨皮质受侵犯以及水肿等更敏感。结果 窗口技术对骨肿瘤的定性和分期具有重要的诊断价值。     

Malignant bilateral mediastinal teratoma: a case report]

The authors report a case of bilateral malignant teratoma of the mediastinum in a 40 year old female presenting with chest pain. Two separate bilateral soft tissue masses were noted in the mediastinum at imaging. On the right side, the mass was heterogeneous with large calcification and infiltration of the pericardium. On the left side, the mass was well defined, heterogeneous and without evidence of local invasion. The analysis of samples obtained by US guided puncture biopsy and surgical specimen of the two masses confirmed the diagnosis of pluricellular malignant teratoma. Mediastinal malignant teratomas represent 1 to 5% of all mediastinal tumors. To our knowledge, no case of synchronous bilateral mediastinal teratoma has never been reported.     

Ultrasonic-guided fine-needle biopsy of osteolytic lesions

Percutaneous biopsy of lytic lesions of the bone, in the past pertaining to orthopedic surgeons, has now become a part of interventional radiology. Fluoroscopic guidance has simplified its execution. US does not, under normal conditions, allow an accurate examination of the skeleton; on the other hand, when the bone tissue is replaced by soft tissue, US can easily demonstrate the presence of a tumefaction, caused by a lytic lesion, and determine its characteristics. Eleven patients with lytic lesions (recognized on plain film) underwent US. The lesions were demonstrated. In such cases, biopsy is essential to define their benign or malignant nature, in the latter case if primitive or metastatic, and their histology as well. US is a simple guide to the biopsy of noncorticalized lytic lesions, and it offers consistent advantages over fluoroscopic guidance--i.e. it is easier to perform, it requires no X-ray exposure, it provides with three-dimensional images, the guide is performed in real time, and a choice of the most appropriate (non-necrotic) areas is possible.     

Cross-sectional imaging of idiopathic solitary renal vein varix: Report of two cases

Two cases of solitary renal vein varices are reported which presented as incidental findings on abdominal computed tomography (CT) and were initially thought to represent retroperitoneal lymph nodes. Contrast-enhanced CT, magnetic resonance imaging (MRI), and Doppler ultrasound (US), all demonstrated the vascular nature of these masses suggesting the correct diagnosis. When a rounded soft tissue density mass is seen on noncontrast-enhanced CT either in or contiguous to the renal hilum, a renal vein varix must be excluded. Doppler US, MRI, or dynamic contrast-enhanced CT should be done to exclude a renal varix as the cause.     

Primary synovial chondromatosis and synovial chondrosarcoma: a pictorial review

This article illustrates the imaging characteristics of primary synovial chondromatosis (PSC) using 20 cases referred to a tertiary orthopaedic oncology centre. Three quarters of patients presented with a large intra-articular soft tissue mass and a suspected clinical and radiological diagnosis of malignancy made in the referring centres. Radiographs demonstrated fine cartilaginous mineralisation in the soft tissue masses in 85% cases and bone erosions were shown on MR imaging in 80%. Malignant transformation to chondrosarcoma was proven in 2 cases with longstanding disease. There were no specific MR features to distinguish these cases with malignant change from PSC alone. Primary synovial chondromatosis should be considered in the diagnosis of the monarticular presentation of an intra-articular soft tissue mass, particularly in the presence of superficial bone erosions and signal voids due to the mineralisation.     

Imaging of Soft Tissue Tumors in the Pediatric Patient

The presence of a soft tissue mass in children is of concern to parents and physicians. Fortunately, these masses are rare and usually benign or pseudotumoral. When dealing with malignant soft tissue tumors, therapeutic options and long-term survival are strongly related to the disease stage at the time of diagnosis. Therefore, when children present with indeterminate or persisting symptoms and posttraumatic, metabolic, or infectious disorders have been ruled out, one should perform dedicated imaging studies (conventional radiography, computed tomography [CT], or both; sonography; magnetic resonance [MR] imaging) to exclude the possibility of a nonpalpable soft tissue mass or to characterize the mass when present. An overview of the use of the different imaging modalities for evaluating soft tissue tumors in the pediatric patient is presented. Because of the numerous benign, malignant, and pseudotumoral soft tissue masses that are often encountered in children, clinical, histologic, and imaging features are presented as concise tables.