Biomedical subjects
Publications and source records attributed to J Somville.
A non-small cell lung cancer presenting as a superior sulcus tumor in an azygos lobe has not yet been reported. We present such a case in a 69-year-old man undergoing complete resection after induction chemoradiotherapy and discuss the specific location of a superior sulcus tumor and the aberrant anatomy of an azygos lobe.
OBJECTIVE: To compare the histopathology of nodular fasciitis (NF) with the magnetic resonance imaging (MRI) findings in order to evaluate the basis of the MR signal characteristics. DESIGN AND PATIENTS: Ten patients with NF, nine females and 1 male, with an age ranging from 13 to 58 years (mean 26.8 years) were studied. MRI findings, available in all 10 patients, were compared with the histopathology in nine patients, and an area-to-area comparative study of the whole specimen section histopathology and MRI was performed in two patients. RESULTS: On the basis of an excisional biopsy or resection specimen, the nine lesions were classified into myxoid ( n=4), cellular ( n=3) and fibrous ( n=2) subtypes. Four myxoid lesions with a subcutaneous location showed a homogeneous SI comparable with muscle on T1-weighted images, high SI on T2-weighted images, and had homogeneous enhancement. One cellular lesion presented with homogeneous, slightly higher SI than muscle on T1-weighted images and inhomogeneous, high SI on T2-weighted images. Alcian blue stain of the whole specimen section revealed the lesion had two parts corresponding to different enhancement patterns on MRI. The blue-stained myxoid part showed markedly diffuse enhancement, while the non-stained cystic space had only peripheral enhancement. Two other cellular lesions had the same appearance on both T1- and T2-weighted images and showed inhomogeneous, diffuse enhancement. One fibrous subtype lesion presented with inhomogeneous, overall slightly higher SI than muscle on T1-weighted images, lower SI at the periphery and high SI in the center on STIR images and only peripheral enhancement. Microscopy and CD-31 staining of the lesion showed more extracellular matrix, with poor vascularity in the center and more collagenous matrix with higher vascularity at the periphery. CONCLUSION: Although similar findings were found in some lesions, the large histologic variability of NF hampers the definition of a prototype of NF on MRI. However, the MRI appearance of the myxoid subtype is rather characteristic. Histologic findings reflect the different SI characteristics and enhancement pattern on MRI.
In the present study different methods for determining the volume of a tumor were evaluated. For 12 models, the real volume, the volume according to measurement of the surface area on MRI, an ellipsoid and a cylindrical approximation of the volume, as well as the maximum diameter, were determined. There appeared to be a good correlation between all calculated volumes and the real volume. The error (mean: 17%) and the standard deviation (SD: 14%) on this error were smallest if the volume was determined by means of determination of the surface area. The ellipsoid approximation resulted in a smaller error (mean: 0%) but a higher standard deviation (SD: 27%). The cylindrical approximation resulted in unacceptable deviations (mean: 51%; SD: 40%). Volume was significantly related to the maximal diameter to the power of 2.3. Volume calculated according to this power resulted in an error of 18%. Standard deviation in this case however was unacceptable (SD: 89%). Volume calculation based upon the determination of the surface area has given the best and most reliable results. Ellipsoid approximation was less reliable, but faster and cheaper. Cylindrical approximation was unacceptable. Size, expressed as maximal diameter of the tumor, was also unacceptable as a parameter for volume.
Primary bone sarcomas of the pelvis represent the most challenging problem in limb-saving surgery. Chondrosarcoma is the most common type, followed by osteosarcoma and Ewing's sarcoma. The symptoms are often vague, so that the diagnosis is made late, when the tumor has already reached a large size. Nowadays hindquarter amputation is reserved for complex tumors involving the sacrum, the sciatic nerve, the iliac vessels or the bladder. Internal hemipelvectomy should be undertaken whenever possible; the reconstructive techniques are based on the three anatomic regions concerned: ilium, periacetabular area, and pubis. Complications occur in more than 50% of the patients. The 5-year survival rate is about 55%. Special scores, such as the MSTS/ISOLS and the TESS score, should be used to make the various studies comparable.
OBJECTIVE: To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts). DESIGN AND PATIENTS: MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, signal intensities on T1- and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study. RESULTS: On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody. CONCLUSIONS: Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well-defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images.
This article outlines the ability of MR imaging in staging, grading, tissue characterization, and posttherapeutic surveillance of soft tissue tumors. Well-known staging parameters, such as extent, relationship with adjacent structures, and detection of intralesional necrosis, are used in the MR protocol for locoregional staging. Bone scintigraphy and high-resolution CT scan of the lungs are best methods for ruling out metastatic spread. A variety of (solitary or combinations of) grading parameters are described in the radiological literature. The role of MR imaging is to afford recognition of these lesions that need further aggressive work-up, excluding all others. Despite controversial reports, the definite role of MR imaging in grading of soft tissue tumors seems to become established. As for grading, a lot of individual imaging characteristics used for tissue characterization have low sensitivity, but combinations of parameters (age, site, signal intensities) are more useful and often allow to predict a specific diagnosis or to narrow down the list of differential diagnoses. Local recurrences of soft tissue tumors are frequent and can be detected accurately by an easy-to-use MR algorithm.
In elderly patients bipolar hip prostheses are often used for intracapsular fractures of the femoral neck and are often complicated by pain after a few years; this pain is frequently related to acetabular erosion seen on xray. In this study 18 bipolar hip prostheses were used in the treatment of a proximal femoral sarcoma in a young patient population (mean age: 39.6 years). Their quality of life was evaluated by TESS and MSTS scores, after a mean follow-up of 81.8 months (range 8-171 months). A radiologic grading system was used to assess acetabular erosion on plain xrays. The patients did not report significant pain, they enjoyed a very good quality of life, and they did not show any obvious acetabular erosion. The use of a bipolar implant appears as a good alternative to total hip replacement in the treatment of relatively young patients who have to undergo proximal femoral tumor resection procedures and have a normal acetabulum.
A 19-year-old man with a high-grade osteosarcoma of the femur, treated with neoadjuvant chemotherapy, surgery, and adjuvant chemotherapy suffered from lung metastases 15 months after diagnosis. They were resected. Thirteen months later, he had vague abdominal complaints which, after analysis, proved to be caused by peritoneal metastasis. A review of the literature, possible physiopathological mechanisms of increased occurrence of unusual metastases and the role of bone scintigraphy in the follow-up of patients with osteosarcoma are discussed.
Botryomycosis is an atypical reaction of the host to a common bacterial infection. A case of botryomycosis mimicking a liposarcoma as suspected on clinical and radiological grounds is described. The diagnosis was made by biopsy and culture of the lesion. A review of the literature is given.
Soft tissue sarcomas account for approximately 1% of all malignancies. They constitute a wide range of different tumor types with very different clinical courses and treatment sensitivities. Our understanding of the molecular mechanisms of tumor growth in sarcomas is increasing rapidly. These new data will probably lead to drastic changes in our current classification systems, which are primarily based on routine microscopy. This might also bring about a more detailed and reliable prognostic evaluation in individual tumors. Hopefully, this knowledge will guide us towards a more rational and more successful development of new therapies. Current surgical approaches and treatment protocols are more or less well defined. Knowledge on when to use ionizing radiation for local control is reasonably clear. Major difficulties however remain for both these treatment modalities in cases of both truncal and retroperitoneal sarcomas. The lack of new very active chemotherapeutic agents against this group of diseases has remained unchanged in the past years, although both the taxanes and the topoisomerase I inhibitors show some activity.
OBJECTIVE: Hyaline cartilaginous tumors are characterized by extremely high signal intensity on T2-weighted images. Recently, some distinctive MR features of cartilaginous bone tumors were reported in small series. Low signal intensity septa surrounding high signal intensity cartilage lobules were seen on T2-weighted images in low-grade chondrosarcomas. On spin-echo T1-weighted images after Gd contrast injection, marked 'septal' or 'ring-and-arc' enhancement was observed in low-grade chondrosarcomas and enchondromas. The purpose of this study was to determine sensitivity and specificity of these MR findings in diagnosis of cartilaginous tumors, and to assess the value of MR in diagnostic workup of these lesions. MATERIALS AND METHODS: Retrospective evaluation of MR findings in 79 cartilaginous tumors and in 79 non-cartilaginous tumors. All lesions were biopsy proven. Each MR examination was independently reviewed by two experienced radiologists without knowledge of clinical data, radiographic and/or CT findings, or histological diagnosis. All lesions were evaluated for morphology (lobular or non-lobular), presence of a high signal intensity mass on T2-weighted images, presence of low signal intensity septa separating high signal intensity lobules on T2-weighted images, and evidence of septal ('ring-and-arc') enhancement. RESULTS: None of the reviewed parameters is useful in diagnosing osteochondromas. Since osteochondromas have a characteristic appearance on plain radiography, the value of MR imaging in the workup of these lesions remains limited. MR findings in enchondromas have a low specificity and a low sensitivity. Low-grade chondrosarcomas, often hard to diagnose on plain radiography and difficult to differentiate from enchondromas, are characterized by the MR tandem of 'low signal intensity septa on T2-weighted images' together with 'septal or ring-and-arc enhancement' (sensitivity 92.3%, specificity 76.5%). High-grade chondrosarcomas are easily recognized on plain radiography. CONCLUSIONS: In differentiating cartilaginous from non-cartilaginous tumors, MR features are highly specific but lack sensitivity. Grading potentials of MR parameters are promising due to the high accuracy in diagnosing low-grade chondrosarcomas.
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