MR imaging of primary bone and soft tissue tumors

MR imaging of 131 cases with pathologically confirmed primary bone and soft tissue tumors were studied. They included 44 bone tumors (25 benign tumors, 19 malignant tumors) and 87 soft tissue tumors (55 benign tumors, 32 malignant tumors). MR imaging was performed on 0.5T, superconductive magnet system. All tumors were evaluated with T1-weighted, T2-weighted and STIR images. In some cases, contrast enhanced MR imaging with Gd-DTPA was applied. MR imaging was proving to be a valuable technique in the evaluation of patients with primary bone and soft tissue tumors. MR imaging was superior to the other modalities in delineating the extent of the tumor and their relation to surrounding structures in all cases. However, plain radiography and CT were more useful for evaluation of calcification, ossification, cortical destruction and endosteal/periosteal reaction than MR imaging. Direct sagittal and coronal images from MR imaging added accurate assessment for the relation between the tumor and their adjacent structures. MR imaging was of limited value in distinguishing benign from malignant tumors with the demonstration of tumor structures only, especially soft tissue tumors. But in bone and soft tissue tumors which have specific morphologic features and intensity patterns, MR imaging was very useful for diagnosis.     

Primary musculoskeletal tumors: examination with MR imaging compared with conventional modalities

In 176 cases of primary musculo-skeletal tumors, the informative value of magnetic resonance (MR) imaging was compared with that of plain radiographic examination, angiography, scintigraphy, and computed tomography (CT). In all patients the surgical and histopathologic results were known. For bone tumors confined to the bone, MR imaging was excellent for evaluation of intraosseous extent, but it could not be proved significantly better than CT or scintigraphy. MR imaging was inferior to plain radiography and CT for evaluation of calcification, ossification, cortical destruction, and endosteal/periosteal reaction. For soft-tissue tumors and bone tumors with soft-tissue extension, MR imaging was significantly better than the other modalities in all variables examined: delineation between tumor and muscle, tumor and vessel, tumor and fat, tumor and joint, and tumor and bone, as well as depicting intralesional necrosis and bleeding.     

Clear cell chondrosarcoma: radiographic, computed tomographic, and magnetic resonance findings in 34 patients with pathologic correlation

Objective To describe the radiographic features of clear cell chondrosarcoma (CCCS), including the computed tomographic (CT) and magnetic resonance (MR) findings, and to correlate them with the histopathologic findings.Design and patients A retrospective review was carried out of 72 patients with histopathologically confirmed CCCS. Imaging studies were available for 34 patients: conventional radiographs (n=28), CT scans (n=14), and MR images (n=15). Radiographic studies were reviewed by three radiologists who rendered a consensus opinion; the studies were correlated with the histopathologic findings.Results Of the 34 patients with imaging studies, 30 were male and 4 were female (mean age 38.6 years; range 11–74 years). Twenty-two lesions were in long bones (15, proximal femur; 1, distal femur; 1, proximal tibia; 5, proximal humerus) and 11 were in flat bones (5, vertebra; 4, rib; 1, scapula; 1, innominate). One lesion occurred in the tarsal navicular bone. Typically, long bone lesions were located in the epimetaphysis (19/22) and were lucent with a well-defined sclerotic margin and no cortical destruction or periosteal new bone formation. More than one-third of the long bone lesions contained matrix mineralization with a characteristic chondroid appearance. Pathologic fractures were present in six long bone lesions (4, humerus; 2, femur). Lesions in the proximal humerus were more likely to have indistinct margins (4/5) and extend into the diaphysis. Flat bone lesions were typically lytic and expansile and occasionally demonstrated areas of cortical disruption. Typically, matrix mineralization, when present, was amorphous. MR imaging, when available, was superior to conventional radiographs for demonstrating the intramedullary extent of a lesion as well as soft tissue extension. CT images better delineated the presence of cortical destruction and the character of matrix mineralization patterns. CCCS lesions were typically low signal intensity on T1-weighted images and moderately or significantly bright on T2-weighted images. Areas of lesion heterogeneity on T1- and T2-weighted images and on post-gadolinium T1-weighted images corresponded pathologically to areas of mineralization, intralesional hemorrhage, and cystic changes. Adjacent bone marrow edema was typically absent (12/15) or only minimally observed in a few cases (3/15). No cases examined with MR imaging demonstrated periosteal new bone formation.Conclusions CCCS typically presents radiographically as a geographic lytic lesion located in the epimetaphyseal region of long bones. Most commonly lesions are found in the proximal femur, followed by the proximal humerus. Lesions within the proximal humerus may exhibit more aggressive features. Lesions in the axial skeleton are typically expansile and destructive, often with soft tissue extension and lack of mineralization. MR imaging may show the presence or absence of bone marrow edema.     

A review of imaging practice in bone and soft tissue lesions.

Thirty six consecutive bone and soft tissue lesions which were referred to the Bone Transplantation Service between January 1987 and June 1989 were reviewed with respect to the information provided by pre-operative CT, MR and plain X-ray and the final histopathologic diagnosis. The ability of CT and MR to demonstrate cortical destruction, periosteal reaction, a soft tissue mass and soft tissue calcification was scored on a scale of one (low suspicion of abnormality) to four (definite abnormality) in each case. Of the thirty six cases reviewed there were twenty-two histologically confirmed tumours with all of the above three imaging modalities available for comparison. In each of these tumours MR was found to provide an equal or more accurate assessment of soft tissue extent. On a scale of 1 to 4 the average point scores were 3.6 and 2.6 for MR and CT respectively. Little difference was shown between CT and MR with respect to medullary involvement (4.0 points vs. 3.9) and cortical destruction (2.5 points vs. 2.7). CT (3.7 points) was more sensitive than MR (1.2 points) in detecting fine soft tissue calcification. In only five cases did the radiology report correctly nominate the histologic diagnosis and thus the role of imaging was more valuable in staging than diagnosis. For this reason a management oriented report should include comment regarding cortical destruction, the intramedullary extent of tumour and the extent of soft tissue involvement. MR is recommended in the investigation of all suspected malignant soft tissue or bone tumours.     

Imaging features of subperiosteal aneurysmal bone cyst

PURPOSE: To analyze the imaging features of subperiosteal aneurysmal bone cyst. MATERIAL AND METHODS: The imaging material of 6 patients with biopsy-proved subperiosteal aneurysmal bone cyst was reviewed. Evaluation included patient demographics, lesion location and size, radiographic features, and intrinsic characteristics on CT and MR images. Review of histologic specimens was carried out by an experienced musculoskeletal pathologist. RESULTS: All lesions were located at the surface of long tubular bones (femur 3, tibia 2, humerus 1): 3 involved the diaphysis, 2 the dia/metaphysis, and 1 exclusively the metaphysis. Lesion size ranged from 2.5 to 6 cm in maximum diameter. Radiographs and CT images always showed a superficial bone defect, which on radiographs demonstrated irregular margins in 4 cases. All lesions caused an interrupted periosteal reaction (shell 3, trabeculated shell 1, Codman angle 2). MR images always showed a multicystic appearance with a hypointense rim, contrast-enhancing cyst walls, and fluid levels. Edema of adjacent soft tissues was present in all cases. CONCLUSION: Aneurysmal bone cyst in a subperiosteal location can demonstrate an aggressive radiographic appearance. MR imaging appears to be most valuable in the differential diagnosis, since it can demonstrate typical morphological features of the underlying process.     

长骨孤立性浆细胞瘤的影像学表现

目的：探讨四肢长骨骨孤立性浆细胞瘤的影像学表现。方法：回顾性分析11例经手术或穿刺活检病理证实的四肢长骨骨孤立性浆细胞瘤的临床及影像学资料,分析其影像学征象。观察指标包括骨质破坏形态、骨皮质改变、骨膜反应、MRI信号特征、瘤周骨髓水肿、软组织改变以及MRI增强改变等。结果：11例肿瘤发生在肱骨4例,股骨7例。11例在X线片和CT上均呈溶骨性骨质破坏伴有轻度的膨胀,边界较清。10例骨皮质变薄,1例骨皮质增厚。9例可见骨皮质呈虫蚀样或锯齿状骨质破坏,未见骨膜反应。所有病例均未见瘤周骨髓水肿,且均可见软组织侵犯,3例可见明显的软组织肿块。与肌肉信号相比,10例T1WI表现为稍高信号,1例呈等信号,11例T2WI表现为高信号。MRI增强扫描,大部分病例表现为明显均匀性强化,仅1例中央可见无强化区。结论：四肢长骨骨孤立性浆细胞瘤的影像学表现具有一定的特征性,X线、CT和MRI综合评价有助于提高四肢长骨骨孤立性浆细胞瘤的诊断准确性。     

原发性骨淋巴瘤的影像表现分析

目的探讨原发性骨淋巴瘤(primary lymphoma of bone,PLB)相关影像表现特点,以提高对该病的诊断和鉴别诊断能力。方法回顾性分析经穿刺细胞学或手术病理证实的7例PLB患者的X线、CT及MRI影像表现。结果 7例患者2例单骨发病,5例多骨发病,最常累及股骨、髂骨,骨质破坏以浸润型为主,骨皮质可见T2WI高信号"肿瘤通道",周围软组织肿块多巨大,累及关节者,关节间隙保持正常。结论 PLB与其它恶性骨肿瘤鉴别困难,但具有以下特点:全身症状轻、溶骨型骨质破坏(尤其长骨远端)伴或不伴骨膜反应及骨皮质增厚、软组织肿块明显而骨质破坏轻微、病变有包绕关节趋势(关节间隙保持正常)。     

Imaging, diagnosis, and staging of bone tumors: a primer

By considering the radiographic appearance in combination with the lesion location and the patient's history, an informed differential diagnosis can be generated for a bone lesion. Primary musculoskeletal malignancies often display aggressive characteristics such as cortical breakthrough, bone destruction, periosteal reaction, and associated soft-tissue masses. On the other hand, benign lesions usually do not have these aggressive features. The matrix mineralization reflects the lesion's underlying pathology and can help to narrow the differential diagnosis.     

Periosteal chondroma: MR characteristics

PURPOSE: The purpose of this study was to describe the MR characteristics of periosteal chondroma. METHOD: MR images of 12 proven cases of periosteal chondroma were analyzed with reference to tumor morphology and size. MR features were correlated with radiographic and pathologic findings. RESULTS: Tumor size ranged from 1 to 7 cm in maximum diameter with a mean value of 2.6 cm. On MR images, a soft tissue mass at the bone surface with pressure erosion of adjacent cortical bone could be identified in all cases. All lesions were bordered by a hypointense rim (100%) and frequently showed a lobulated configuration (75%). Edema of medullary bone or soft tissues was not observed in any of the cases. Signal intensity of cartilaginous tumor tissue was typically hypo-or isointense relative to muscle on T1-weighted (100%) and hyperintense relative to fat on T2-weighted (92%) and T2*-weighted (100%) MR images. Radiographically significant calcifications of the tumor matrix, present in half of the cases, caused focal signal loss on MR images of all pulse sequences. Contrast enhancement was observed predominantly at the periphery of the lesions (100%), which on pathologic examinations typically contained fibrovascular bundles, surrounding the cartilage lobules. CONCLUSION: Periosteal chondroma appears to have a relatively typical MR appearance, which reflects the histologic composition of the lesion. In addition to radiography, MRI therefore can substantially aid in the preoperative diagnosis of this rare bone lesion.     

足跗骨软骨母细胞瘤的影像学表现

目的:总结分析足跗骨软骨母细胞瘤的影像学表现。方法:回顾性分析经临床病理证实的发生于足跗骨的5例软骨母细胞瘤的X线、CT及MRI表现。结果:5例均单发,2例位于跟骨,2例位于距骨,1例位于舟骨。X线主要表现为圆形或卵圆形透亮影,边界清楚,5例均可见病灶边缘硬化带形成,病灶内未见明显钙化。CT扫描显示肿瘤呈膨胀性生长,骨质破坏区边界锐利、硬化,灶周软组织肿胀,未见骨膜反应及软组织肿块,增强扫描呈轻度不均匀强化。MRI可见病灶形态呈分叶状,呈长、稍长T1信号,混杂T2信号,伴有灶周骨髓水肿及关节腔积液,灶周软组织水肿,增强扫描亦呈轻度不均匀强化。结论:足跗骨软骨母细胞瘤较少见,其影像学表现具有一定特征性。     

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。     

Skeletal complications in pediatric oncology patients.

Pediatric oncology patients are at risk for the development of numerous skeletal complications, and radiologic studies are important in the identification and evaluation of these conditions. Methotrexate osteopathy manifests as osteopenia, dense provisional zones of calcification, pathologic fractures, and sharply outlined epiphyses. Hypertrophic osteoarthropathy may occur with nasopharyngeal carcinoma or tumors of the lungs or pleura and manifests as cortical thickening, lamellar periosteal new bone formation, and soft-tissue swelling. Biomechanical abnormalities are often seen at bone scintigraphy in patients who have undergone surgery for bone tumors. Growth plate injury may manifest as marked deformity, sclerotic metaphyseal bands, metaphyseal fraying, and longitudinal striations. Radiation "osteitis" is seen as an initial decrease in bone density with subsequent development of a mixed radiolucent and sclerotic appearance. Ischemic necrosis of the femoral heads is best demonstrated at magnetic resonance (MR) imaging and has low signal intensity on T1-weighted images and a high-signal-intensity rim on T2-weighted images. Bone infarcts are seen as well-demarcated, often ring-shaped areas of decreased signal intensity on T1-weighted MR images and as areas of increased signal intensity on short-inversion-time inversion recovery images. Radiographic signs of infection include bone destruction, periosteal new bone formation, and sclerotic changes. Short-inversion-time inversion recovery MR imaging is particularly useful in evaluating posttherapy changes in bone marrow. Osteochondroma may demonstrate a cartilaginous cap at MR imaging, whereas the most important finding in radiation-induced sarcoma is a soft-tissue mass. Radiologists who work with children with cancer need to be familiar with these complications and their imaging appearances.     

Giant cell tumors of the tendon sheath may present radiologically as intrinsic osseous lesions

The purpose of this study was to explain radiographic features of giant cell tumors of the tendon sheath (GCTTS), in particular, osseous extension, by correlating imaging findings with histology in order to increase the accuracy of radiological diagnosis. In a series of 200 consecutive osseous (pseudo) tumors of the hand, on radiography, six patients presented with an intrinsic osseous lesion caused by a histologically confirmed neighboring GCTTS. Available radiographs, computed tomography (CT), and contrast-enhanced magnetic resonance (MR) images were correlated with histology. Radiography showed osseous lesions consisting of well-defined cortical defects in four (one of whom also demonstrated cortical scalloping) and a slightly expansile, well-defined osteolytic lesion in two patients. MR obtained in four patients showed the extraosseous tumor invading/eroding bone and causing cortical scalloping (three and one patients, respectively). Extension depicted on MR was confirmed on the two available resection specimens. All lesions were polylobular (cauliflower or mushroom like) and neighbored tendon sheaths. Dense collagen and hemosiderin-loaded macrophages explained the high CT attenuation and the low MR signal intensity on T2-weighted images that was observed in all four MR and in all two CT scans. The high density of proliferative capillaries explained the marked enhancement observed in all four patients with gadolinium (Gd)-chelate-enhanced MR imaging. GCTTS is a soft tissue (pseudo) tumor that may invade bone and as a consequence mimick an intrinsic osseous lesion on radiographs. In such cases, specific MR and CT features that can be explained by histological findings can be used to suggest the correct diagnosis.     

Skeletal lymphoma

The records of forty-two patients with lymphoma of bone [.11 with Hodgkin disease (HD), 31 with non-Hodgkin lymphoma (NHL)] were retrospectively reviewed to correlate histologic type with sites of osseous involvement, radiographic patterns of bone destruction, and prognosis. The vertebral column was the most frequent site of axial involvement and the femur was the commonest site overall. In HD, the most frequent radiographic pattern was vertebral sclerosis, while periosteal reaction was noted in two focal femoral lesions and hypertrophic pulmonary osteoarthropathy in one patient. In NHL, permeative destruction predominated, while unusual layered periosteal reaction and eccentric cortical destruction were each seen in two patients. Radiographic patterns of bone involvement alone cannot be used to predict histologic type or prognosis. Staging remains the most important prognostic indicator. For skeletal lymphoma, instead of the traditional Ann Arbor Staging System, we prefer the more specific Mayo Staging System which relates the temporal appearance of osseous disease to nodal or soft-tissue disease or both.     

Periosteal ganglion: a report of three new cases including MRI findings and a review of the literature

 Objective. To clarify the clinicopathological features of periosteal ganglion. Design. Three patients with periosteal ganglion were studied clinicopathologically. Patients. One patient was selected from the files of our institute and two from a consultation file. Results and conclusions. All three lesions were located over the medial aspect of the tibia. Plain radiographs showed cortical erosions of varying degrees and mild periosteal reaction of the medial side of the tibia. MR images demonstrated well-circumscribed lesions overlying the cortical bone of the tibia, shown as low-intensity areas on T1-weighted images. On T2-weighted images, lesions were homogeneous, lobulated, and showed a characteristic markedly increased signal intensity. These findings are helpful in making a diagnosis of periosteal ganglion. Each patient had an uneventful clinical course after an excision involving the wall of the ganglion, the adjoining periosteum, and the underlying sclerotic cortical bone.     

骨原发性恶性纤维组织细胞瘤影像诊断

目的探讨骨原发性恶性纤维组织细胞瘤(BMFH)影像表现及诊断要点。方法回顾性分析6例经病理确诊为BMFH的X线、CT及MRI表现。结果4例侵犯单骨,2例侵犯多骨。溶骨型4例,混合型2例。股骨下端3例,肱骨上端1例,楔骨1例,横突1例,共侵犯12个骨骼。6例均有骨及骨皮质明显破坏,以溶骨性破坏为主,2例病灶周围有轻度骨硬化。全部病例均有软组织肿块,巨大肿块2例,局限性肿块4例,1例肿块内可见散在小钙化影。全部病例未见骨膜反应,3例合并病理性骨折。结论原发性BMFH好发于长骨干骺端或骨端,多见于股骨下端及胫骨上端。虫蚀状或大片状溶骨性骨质破坏,巨大软组织肿块,无骨膜反应,是其影像学特点,诊断需密切结合临床和病理。     

骨小细胞恶性肿瘤的影像特征分析

目的 分析骨小细胞恶性肿瘤（SCMT）的临床及影像表现,以提高临床诊断水平。 方法 回顾性选取经病理证实的骨SCMT病人75例,其中恶性非霍奇金淋巴瘤（MNHL）25例[男20例、女5例,平均年龄（50.0±18.3）岁],骨的浆细胞瘤（PB）37例[男20例、女17例,平均年龄（59.1±12.4）岁]、尤文肉瘤（ES）13例[男11例、女2例,平均年龄（17.1±6.7）岁]。分析3种肿瘤病人临床资料、病灶X线摄影或CT特征及MRI特征。采用单因素方差分析、卡方检验或Fisher确切概率检验比较3组病人的临床资料和影像特征分布。 结果 3组间年龄、性别、骨质破坏类型、骨皮质破坏类型、膨胀性改变和残留骨嵴、病灶周围水肿、软组织肿块、骨膜反应差异均有统计学意义（均P<0.05）。MNHL组及PB组病人的平均年龄均高于ES组,3组男性均多于女性。3组X线及CT特征中,PB组中骨质破坏、骨皮质破坏、膨胀性改变及病变内残留骨嵴征象的占比均高于其余2组;其中PB组病人均可见骨质破坏和骨皮质破坏（100%）,且骨质破坏多呈溶骨性改变（90.6%）,并以骨皮质缺损多见（84.4%）。3组MRI特征中,ES组出现病灶周围水肿、软组织肿块和骨膜反应的占比均最高,其次为MNH组和PB组。ES组出现软组织肿块的占比高达100%,MNHL组和PB组中出现骨膜反应者仅占5.6%和4.8%。3组发生部位、T₂WI信号特点间的差异均无统计学意义（均P>0.05）。 结论 结合病人的年龄及影像学表现有助于鉴别骨SCMT。     

骨巨细胞瘤影像学

骨巨细胞瘤是一种常见的骨原发性肿瘤，本文通过对文献的复习，系统地介绍骨巨细胞瘤的临床、病理、X线、CT和MRI的表现特点，认为骨巨细胞瘤的影像学表现有一定的特征性，典型的X线表现为长管骨骨端偏心性、膨胀性、皂泡样、达关节软骨下骨边界清楚的溶骨性骨质破坏；典型的CT表现为骨端偏心性、膨胀性、溶骨性骨质破坏，骨皮质变薄，连续性完整或栅栏状中断，肿瘤的边缘可有程度不等、断续的骨质硬化，肿瘤内可见有短小的骨嵴；典型的MRI表现为长骨骨端偏心性、达关节软骨下骨的异常信号区，T1WI为中等信号，T2WI为中、高信号混杂，可出现液一液平，肿瘤的边缘有一相对比较规则的、由于周围骨质硬化引起的T1WI及T2WI均为低信号的线状影；影像学检查对于骨巨细胞瘤的诊断、鉴别诊断及治疗后随访均有重要的价值。     

软骨母细胞瘤的影像诊断价值

目的：分析软骨母细胞瘤的影像学特征及诊断价值。方法：回顾性分析24例经病理证实的软骨母细胞瘤的影像学资料,其中24例均有X线平片,20例CT扫描,12例MRI检查。结果：24例中,X线表现为骨质破坏（22例）,病灶周围硬化边（15例）,病灶内明显的斑点状及片状钙化（14例）。20例CT均显示清晰骨质破坏及硬化边,伴有明显的斑点/片状钙化（18例）,骨膜反应（5例）及周围软组织肿胀（9例）。12例MRI显示边界清楚的长T1、长短混杂T2信号,5例可见明显的骨髓水肿,3例显示骨膜反应,增强4例强化较明显。结论：软骨母细胞瘤的影像学表现多具有一定的特征性,综合分析X线、CT、MRI表现有助于正确诊断。     

Periosteal chondroid tumors: radiologic evaluation with pathologic correlation

OBJECTIVE: The purpose of this study was to determine whether the imaging features of periosteal chondroid tumors correlate with histopathology. MATERIALS AND METHODS: Twenty-two patients (nine women and 13 men; mean age, 33 years) with pathologically proven periosteal chondroid lesions were retrospectively reviewed. The imaging modalities included conventional radiography (n = 17), CT (n = 10), and MR imaging (n = 14). The images were reviewed by two osteoradiologists, with agreement by consensus. Evaluation criteria included lesion location, mineralization, and size; periosteal reaction; and cortical response. Intramedullary extension, adjacent intramedullary edema, soft-tissue edema, and intrinsic characteristics were also evaluated on MR imaging. After the evaluation, a radiologic diagnosis of chondroma or chondrosarcoma was obtained. An experienced osteopathologist who was unaware of the patient's medical history and radiologic findings reviewed all histopathology. Agreement between the radiologic and the histopathologic diagnosis was tested using the kappa analysis. Imaging features were correlated with the pathologic findings, and a statistical analysis was performed. RESULTS: Using strict pathologic criteria, we diagnosed 11 chondromas and 11 chondrosarcomas (nine, grade I; two, grade II). Moderate agreement was reached between the radiologic and the pathologic diagnosis (kappa = 0.55). The size of periosteal chondrosarcomas (range, 3-14 cm; median, 4 cm) was considerably larger than the size of the chondromas (range, 1-6.5 cm; median, 2.5 cm; p < 0.05). Other imaging features did not significantly correlate with benign versus malignant disease at pathology (all p > 0.05). CONCLUSION: A variable overlap existed in the imaging appearances of benign and malignant periosteal chondroid lesions, with size being the most reliable indicator in distinguishing the two lesions. This and the fact that histologic differentiation of the entities can be difficult, suggests that surgical wide excision may be the most appropriate procedure in treating patients with lesions greater than 3 cm.