Imaging findings of extrapulmonary metastases of osteosarcoma

PURPOSE: To review imaging findings of extrapulmonary metastasis from osteosarcoma and to evaluate them for any consistent pattern and correlation between imaging findings. MATERIALS AND METHODS: This study was retrospectively conducted in 13 patients with extrapulmonary metastasis of pathologically confirmed osteosarcoma. We evaluated the radioisotope (RI) scans (n=16), ultrasonography (USG) (n=4), computed tomography (CT) scans (n=10), MRIs (n=6), clinical records, and pathological reports for assessment of imaging findings and correlation between radiologic findings and RI uptake of the lesions. Points evaluated were the following: uptake on RI scans, presence of mineralization on CT, and MRI, size, enhancement pattern, attenuation on CT, signal intensity (SI) on MRI, and echogenicity on USG. RESULTS: Extrapulmonary metastatic sites were diverse, including another bone other than the primary site (n=6), lymph node (n=4), pleura (n=2), liver (n=2), pancreas (n=1), kidney (n=1), peritoneum (n=1), muscle (n=1), and subcutaneous fat layer (n=1). One patient had tumor growth within the pulmonary artery and jejunum. Among 21 metastatic sites in 13 patients, bone scan was performed in 16 cases and RI uptake was detected in 10 lesions. Calcification was detected in eight lesions on radiologic imaging, including plain radiography, USG, CT, and MRI. Two lesions showed RI uptake without definite calcification or ossification on MRI and plain radiography, respectively. We analyzed the enhancement pattern and mass size in 18 metastatic sites and these factors had poor correlation with uptake on RI scans. CONCLUSION: The sites and imaging findings of extrapulmonary metastasis of osteosarcoma were variable. All the lesions with mineralization were detectable on RI scans prior to radiologic imaging. RI scan has a limited role in the evaluation of metastatic lesions without mineralization.     

不同病理类型骨肉瘤的影像学表现初探

目的：探讨不同病理类型骨肉瘤的X线、CT及MRI表现。方法：搜集经病理证实的23例骨肉瘤患者的影像学资料,其中23例均行X线检查,22例行CT检查,19例行MRI检查,分析其X线、CT及MRI表现。结果：23例中骨母细胞型骨肉瘤10例,均可见不同类型的瘤骨;纤维母细胞型骨肉瘤6例,以溶骨性破坏为主,部分病例见少量瘤骨;软骨母细胞型骨肉瘤5例,可见成簇分布的点状、环状的瘤骨,增强扫描呈环状／花边状／间隔强化;血管扩张型骨肉瘤1例;小圆细胞型骨肉瘤1例。结论：X线、CT及MRI对不同病理类型的骨肉瘤的诊断及鉴别诊断有一定作用。     

Imaging recurrent parosteal osteosarcoma

The aim of this study was to document the imaging features of recurrent parosteal osteosarcoma. The clinical and imaging records of 33 patients with a parosteal osteosarcoma referred to an orthopaedic oncology service over a 17-year period were retrospectively reviewed. The mode of identification of locally recurrent tumour was noted, together with the management and clinical outcome. Five patients developed a local recurrence of their parosteal osteosarcoma ranging from 6 months to 10 years after initial surgery. In 4 patients the recurrence was first suspected clinically due to the development of a mass. In the fifth patient recurrence was first detected on routine follow-up radiography. In 4 patients the recurrence could be identified on radiography as a mineralized mass. All the recurrences were readily identified on MR imaging, despite artefacts from prostheses. The recurrences were also evident in the 3 cases in which bone scintigraphy was performed. Local recurrence of parosteal osteosarcoma is adequately detected with a combination of clinical examination and conventional radiography. MR imaging is required to stage local recurrence or where radiography has failed to confirm clinically suspected recurrence. The routine use of MR imaging to follow-up patients is of doubtful value because of the frequently long time between initial surgery and relapse. Received: 23 June 2000 Revised: 7 August 2000 Accepted: 9 August 2000     

Computed tomographic findings in primary mandibular osteosarcoma

Osteosarcoma of the mandible is a rare tumour. Two cases examined by computed tomography (CT) are presented. The osteolytic, osteoblastic and extra-osseous components are excellently shown by CT. The attenuation coefficient of calcified and non-calcified osteoid is extremely variable, with densities ranging from +19 to +320 EMI units. The extension of lesions into the pterygopalatine fossa, infratemporal fossa and cranial cavity are precisely defined on CT, information which is necessary for surgical and radiotherapy planning.     

Primary vertebral osteosarcoma: imaging findings

PURPOSE: To evaluate patient age and sex and location and imaging appearances of primary vertebral osteosarcoma (PVOS) compared with histologic subtypes. MATERIALS AND METHODS: Retrospective review (1915-2001) of imaging findings in patients with histologically proved primary osteosarcoma of vertebral column was performed. Two radiologists in consensus reviewed findings for location, origin site, matrix pattern, and spinal canal invasion and compared them with histologic subtypes. Radiation-induced, Paget, metastatic, and multifocal osteosarcoma were excluded. RESULTS: Of 4,887 osteosarcoma cases, 198 (4%) were PVOS arising from vertebral column. There were 103 female and 95 male patients (age range, 8-80 years; median age, 34.5 years). Involvement included cervical (27 patients), thoracic (66 patients), lumbar (64 patients), and sacral (41 patients) spine. Adequate imaging findings were available in 69 patients, and involvement of two levels was seen in 12 (17%). In nonsacral spine, most tumors (44 cases) arose from posterior elements, with partial involvement of vertebral body. Lesions confined to vertebral body were less frequent (12 cases). Sacral tumors involved body and sacral ala. The most common histologic subtypes were osteoblastic (47 patients), chondroblastic (12 patients), telangiectatic (four patients), fibroblastic (four patients), small cell (one patient), and epithelioid (one patient). The majority (55 cases) demonstrated osteoid matrix mineralization; 17 showed marked mineralization. Five cases with marked mineralization were confined to vertebral body, with "ivory vertebra" appearance. Purely lytic pattern was seen in 14 (20%) cases. Lytic pattern was seen in four (100%) telangiectatic, three (75%) fibroblastic, three (25%) chondroblastic, three (6%) conventional osteoblastic, and one (100%) small-cell subtypes. Invasion of spinal canal was common (84% of cases). Appearance simulating osteoblastoma without soft-tissue mass was present (seven cases). Pathologic compression fractures were identified (seven patients). CONCLUSION: This study provides age and sex distribution and location and imaging features in a large series of PVOS.     

Imaging findings in epithelioid hemangioendothelioma

Purpose-objectiveEpithelioid hemangioendothelioma (EHE) is a rare vascular malignancy with varying biologic behavior. The purpose of this study was to identify imaging findings most characteristic of EHE.MethodsRetrospective review of clinical and imaging records in patients referred to our Vascular Anomalies Center over a 17 year period with biopsy proven EHE.ResultsWe evaluated 29 patients (17 F) with median age of 16 years (range 2–76 y). The most common presenting symptoms were pain (n = 13) and palpable mass (n = 7). 22 (70%) had multifocal disease. Most common sites of involvement were lung (n = 25), liver (n = 16), bone (n = 12), soft tissue (n = 3) and lymph nodes (n = 1). Of patients with single site disease, 3 had lung, 3 liver, and 1 had bone lesions. In 18/25 with lung disease, there were multiple nodules of varying sizes and characteristics. In 14/16 with hepatic disease there were multiple nodules with predominantly peripheral distribution. Subcapsular retraction was seen in 10/16 and a “lollipop” sign (hepatic or portal vein tapering at the edge of a well-defined hypoenhancing lesion) identified in 5/16. Of 12 osseous lesions, 11 were lytic, 8 involved vertebrae and 9 involved the axial skeleton.ConclusionEHE has varied imaging findings. The most common sites are lungs, liver, and bone, with multi-organ involvement seen in most. Lung disease is most commonly characterized by multiple nodules. Hepatic lesions demonstrate the most distinctive findings, with peripheral distribution, lack of early enhancement, subcapsular retraction and “lollipop” sign. Osseous lesions are commonly lytic and more prevalent in the axial skeleton.     

Imaging findings in Takayasu's arteritis

OBJECTIVE: The objective of our study was to evaluate the clinical usefulness of cross-sectional imaging for establishing the diagnosis of Takayasu's arteritis (TA), an inflammatory vascular disorder that produces arterial stenoses and aneurysms primarily involving the thoracoabdominal aorta and its branches and the pulmonary arteries. CONCLUSION: CT and MRI findings of TA include vascular wall thickening and enhancement early in the disease, and arterial stenoses, occlusions, and aneurysms later in the disease. Cross-sectional imaging is useful for establishing the diagnosis of TA and for showing response to nonsurgical therapy or for planning a surgical intervention.     

Imaging findings in epithelioid hemangioendothelioma

Purpose-objectiveEpithelioid hemangioendothelioma (EHE) is a rare vascular malignancy with varying biologic behavior. The purpose of this study was to identify imaging findings most characteristic of EHE.MethodsRetrospective review of clinical and imaging records in patients referred to our Vascular Anomalies Center over a 17 year period with biopsy proven EHE.ResultsWe evaluated 29 patients (17 F) with median age of 16 years (range 2–76 y). The most common presenting symptoms were pain (n = 13) and palpable mass (n = 7). 22 (70%) had multifocal disease. Most common sites of involvement were lung (n = 25), liver (n = 16), bone (n = 12), soft tissue (n = 3) and lymph nodes (n = 1). Of patients with single site disease, 3 had lung, 3 liver, and 1 had bone lesions. In 18/25 with lung disease, there were multiple nodules of varying sizes and characteristics. In 14/16 with hepatic disease there were multiple nodules with predominantly peripheral distribution. Subcapsular retraction was seen in 10/16 and a “lollipop” sign (hepatic or portal vein tapering at the edge of a well-defined hypoenhancing lesion) identified in 5/16. Of 12 osseous lesions, 11 were lytic, 8 involved vertebrae and 9 involved the axial skeleton.ConclusionEHE has varied imaging findings. The most common sites are lungs, liver, and bone, with multi-organ involvement seen in most. Lung disease is most commonly characterized by multiple nodules. Hepatic lesions demonstrate the most distinctive findings, with peripheral distribution, lack of early enhancement, subcapsular retraction and “lollipop” sign. Osseous lesions are commonly lytic and more prevalent in the axial skeleton.     

Imaging findings in rabies encephalitis

SUMMARY: Rabies encephalitis is perhaps one of the few infectious diseases that command attention and fear not only from the layman but also from physicians. The unique mode of transmission, the virtually exclusive neurotransmission shown by the agent, and the complete hopelessness of the established disease sets rabies apart from other zoonoses transmitted to man. Rabies encephalitis is a fatal disease and its diagnosis is usually based on the clinical presentations and findings. Hence, imaging in rabies is seldom done, and imaging findings in rabies encephalitis have rarely been described. We present the imaging findings in two confirmed cases of rabies encephalitis in which antemortem diagnosis was obtained by corneal impression smears showing the presence of viral antigens. The differential diagnosis of the imaging findings as well as the role and the relevance of imaging in the diagnosis of this disease are discussed. The current literature on the subject is also reviewed.     

Imaging findings in intracranial aspergillosis

RATIONALE AND OBJECTIVES: The authors' purpose was to elucidate the various computed tomographic (CT) and magnetic resonance (MR) imaging findings in intracranial aspergillosis. MATERIALS AND METHODS: Retrospective analysis of cranial imaging findings was performed in eight proved cases of central nervous system aspergillosis. The patients ranged in age from 17 to 75 years. Four patients were immunocompromised, and four were immunocompetent. CT was performed in all eight patients, and MR imaging in five. RESULTS: Six patients (75%) had multiple lesions seen on the imaging studies, with a total of 27 focal brain lesions demonstrated. The lesions were most commonly seen in the cerebral hemispheres (n = 21), with lesser involvement of the basal ganglia (n = 2) and the posterior fossa (n = 4). Seven lesions were hemorrhagic on CT and/or MR images. There was a correlation between lesion size and hemorrhage, with hemorrhage more likely in larger lesions (>15 mm). At pathologic examination, foci of hemorrhage were noted within both infarcts and abscesses. Enhancement was noted in five lesions, four of which were confirmed abscesses. Contrast enhancement of the lesions was vague and week in immunocompromised patients but solid and strong in immunocompetent patients. There were 18 lesions without hemorrhage or enhancement; they were either infarcts or abscesses at pathologic examination. Some of these small nonhemorrhagic nonenhancing brain lesions in the subcortical white matter mimicked lacunar infarcts. CONCLUSION: Typical imaging findings of intracranial aspergillosis include multifocal lesions involving the cerebral hemispheres, with hemorrhage in approximately 25% of lesions. Lesional contrast enhancement tends to be stronger in immunocompetent hosts.     

Radiological findings in an unusual osteosarcoma in the maxilla

An unusual case of osteosarcoma of the maxilla, which was initially diagnosed as fibrous dysplasia on the basis of the clinical CT and histopathological findings, is presented. However, panoramic and periapical radiography suggested a malignant neoplasm. After surgery, the tumor was diagnosed histopathologically as a low-grade osteosarcoma. We conclude that panoramic and periapical radiographs are important adjuncts and should be included in any investigation of the jaws where CT scanning is unable to differentiate between osteosarcoma and fibrous dysplasia.     

Extraskeletal osteosarcoma: spectrum of imaging findings

OBJECTIVE: The purpose of this article is to present the spectrum of imaging findings of primary and metastatic extraskeletal osteosarcoma and highlight the differences from primary osteogenic osteosarcoma in bone. CONCLUSION: Extraskeletal osteosarcoma is a rare mesenchymal malignancy of soft tissue, histologically indistinguishable from primary osteosarcoma of bone. However, there are distinct differences in demographics, imaging features, prognosis, and management compared with osteogenic osteosarcoma. Imaging characteristics reflect tumor morphology, with only 50% of primary tumors showing mineralization. Metastases may or may not show mineralization, even if present in the primary tumor. The overall prognosis is poor.     

Primary mesenteric extraskeletal osteosarcoma: imaging findings

We present a case of extraskeletal osteosarcoma arising from the root of the mesentery. This location is extremely rare; to our knowledge only three other cases have been reported. We describe the findings at computed tomography, positron emission tomography, and bone scintigraphy. We emphasize the radiologic differential diagnosis in this case, which was complicated by the presence of other malignant abdominal disease.     

富于巨细胞型骨肉瘤的影像学诊断

富于巨细胞型骨肉瘤(giant cell-rich osteosarcoma,GCRO)是骨肉瘤的一种罕见亚型,约占原发性骨肉瘤的1%~3%[1].因GCRO的临床、影像和病理学表现酷似骨巨细胞瘤,容易误诊.笔者回顾性分析经手术病理或CT引导下穿刺病理证实的4例GCRO资料,复习相关文献,总结其临床及影像特征,以提高对GCRO的认识.     

Imaging of periosteal osteosarcoma: radiologic-pathologic comparison

PURPOSE: To review the imaging appearance of periosteal osteosarcoma, with pathologic comparison. MATERIALS AND METHODS: Data for 40 pathologically confirmed periosteal osteosarcomas were retrospectively reviewed. Patient demographic data were recorded, and radiographs (n = 40), bone scintigrams (n = 10), angiograms (n = 2), and computed tomographic (CT) (n = 11) and magnetic resonance (MR) (n = 12) images were evaluated for lesion location and size, cortical changes, marrow involvement, and intrinsic characteristics by two musculoskeletal radiologists, with agreement by consensus. Pathology reports were reviewed for presence and predominance of histologic components (fibrous, chondroid, and osteoid), tumor grade, and marrow involvement. RESULTS: There were 25 male (62%) and 15 female (38%) patients with an age range of 10-37 years (average age, 20 years). The most frequent lesion locations were the diaphysis of the tibia (16 patients) or of the femur (15 patients). Radiographs showed a broad-based soft-tissue mass that was attached to the cortex (all patients) and showed cortical thickening (33 patients), cortical scalloping/erosion (37 patients), and/or perpendicular periosteal reaction (38 patients) extending into the soft-tissue mass. Soft-tissue masses were well defined in 91%-100% of cases and surrounded a median of 50%-55% of the cortex. Lesions commonly showed low attenuation at CT (10 patients) and high signal intensity on T2-weighted MR images (10 patients), reflecting the high water content of these largely chondroblastic lesions. Focal areas of adjacent marrow replacement were common at MR imaging (nine patients) but represented reactive changes unless they were in direct continuity with the overlying soft-tissue mass (this was rare, occurring in only one patient, and represented marrow invasion). Review of pathology reports revealed that all lesions contained chondroid tissue, which predominated in 34 patients. CONCLUSION: The radiologic appearance of periosteal osteosarcoma is a broad-based surface soft-tissue mass causing extrinsic erosion of thickened underlying diaphyseal cortex and perpendicular periosteal reaction extending into the soft-tissue component. Reactive marrow changes are commonly seen at MR imaging, but true marrow invasion is rare.     

软骨肉瘤的影像学诊断

目的:探讨软骨肉瘤的影像学诊断。方法:回顾性分析经病理证实的32例软骨肉瘤的影像学特点。32例均行X线平片检查,其中25例行CT检查,MR检查14例。结果:32例平片发现病变内钙化28例。25例做CT者均见骨质破坏和钙化影,软组织肿块21例,骨膜反应2例。MR表现:肿瘤呈等长T1长T2为主的混杂信号,可见长T1短T2信号分隔,增强扫描示分隔强化和肿块周边部强化,钙化呈长T1短T2信号。结论:骨质破坏、钙化、软组织肿块、弓环状分隔等构成软骨肉瘤的主要影像学特点,对诊断和鉴别诊断具有重要价值。