ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;Distinguishing between the various types of bone lesions that contain multinucleated giant cells is of great practical importance because appropriate treatment depends upon diagnostic accuracy. Neoplastic or tumor‐like destructive lesions of bone such as giant cell tumor, chondroblastoma, and aneurysmal bone cyst often require aggressive therapy. Giant cell reparative lesions, which may mimic giant cell tumors histologically, may also be locally aggressive, but they often require comparatively little therapy. Space‐occupying bone lesions caused by hyperparathy‐roidism (“brown tumors”) should be avoided surgically and the cause of hyperparathyroidism corrected. When developmentally self‐limited lesions of bone containing giant cells such as fibrous cortical defect (non‐ossifying fibroma) are examined via biopsy, they may cause histologic confusion with giant cell tumors if the radiographs are not reviewed. Their accurate differentiation is possible only if adjunctive clinical, radiographic, and biochemical data are known. Selective illustrations and a diagnostic algorithm are provided.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;Mesenchymal chondrosarcomas are relatively rare but have characteristic histologic features. These include the presence of scattered areas of more or less differentiated cartilage and highly vascular spindle‐cell or round‐cell mesenchymal tissue, often with a hemangiopericytomatous pattern. These are generally highly malignant. “Dedifferentiation” of a histologically low‐grade and clinically indolent cartilage tumor occurs in approximately 10% of all chondrosarcomas. It is characterized by a highly anaplastic sarcoma juxtaposed with a borderline or low‐grade malignant cartilage tumor. There is typically an abrupt transition between the components. Some researchers consider clear cell chondrosarcoma a rare variety of chondrosarcoma. Histologically, it is a low‐grade malignancy characterized by rounded cells with conspicuous clear or vacuolated cytoplasm and by a cartilaginous or chondroid matrix in some areas.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;Adamantinoma of long bones is a rare, low‐grade malignant bone tumor occurring predominantly in the tibia. A variety of morphologic patterns of classic adamantinoma have been described, including basaloid, tubular, squamoid, spindle, and osteofibrous dysplasia‐like patterns. Osteofibrous dysplasia is a benign fibro‐osseous lesion commonly involving the tibial diaphysis. An intracortical localization, fibrous tissue and bone trabeculae surrounded by rims of osteoblasts without distinct epithelial cell nests, and scattered cytokeratin‐positive cells are characteristic features of osteofibrous dysplasia. Osteofibrous dysplasia‐like adamantinoma is a less‐aggressive variant of long bone adamantinoma, in which the lesion is confined to the cortex and histologically shows small but distinct epithelial cell nests in the osteofibrous dysplasia—like tissue. The close relationship between adamantinoma and osteofibrous dysplasia has only recently been recognized. These entities could be categorized with classic adamantinoma and osteofibrous dysplasia at opposite ends of the spectrum and osteofibrous dysplasia—like adamantinoma in the middle. It is unclear whether osteofibrous dysplasia—like adamantinoma is a regressive form of adamantinoma or if it progresses into classic adamantinoma. More follow‐up data are required to resolve the controversy concerning osteofibrous dysplasia and adamantinoma

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

&NA;A 13‐year‐old boy had a painful longitudinal swelling over the lateral aspect of the right calf. Radiographic studies revealed a dense fibular diaphyseal lesion with an associated soft tissue mass interpreted as probable Ewing's sarcoma. In contrast to the expected small round cell tumor appearance, the biopsy tissue was composed of nests of hyperchromatic, mildly pleomorphic cells separated by a pronounced desmoplastic reaction. Immuno‐phenotyping showed that the tumor cells were strongly keratinand vimentin‐immunoreactive but negative for 0‐13 (MIC2). Other epithelial‐like features included the presence of abundant intermediate filaments (including tonofilaments) and complex desmosomal‐type intercellular junctions. These histologic, immunohistochemical, and ultrastructural findings were consistent with a diagnosis of adamantinoma, an entity that is not usually considered in the differential diagnosis of Ewing's sarcoma. Genetic analysis of this patient's tumor specimen, in addition to two cases previously described in the literature as “Ewing‐like adamantinomas,” revealed the presence of the 11;22 translocation [t(11; 22)(q24;q12)] and/or the associatedEWS/FLI1fusion transcript characteristic of Ewing's sarcoma and peripheral primitive neuroectodermal tumors. This case illustrates the diagnostic challenges often encountered in bone and soft tissue tumors. Recently, recognition of specific cytogenetic and molecular genetic abnormalities in these neoplasms has significantly reduced some of the associated difficulties and has provided valuable information with respect to histopathogenesis. A review of the diagnostic and prognostic usefulness of genetic studies in Ewing's sarcoma and peripheral primitive neuroectodermal tumors is presented.

ISSN:1082-9784    

出版商:OVID    

年代:2000

数据来源: OVID