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Query: UMLS:C0027121 (myositis)
 4,538 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of clear-cell chondrosarcoma occurred in the proximal femur of a 32-year-old man. The tumor was complicated by a focus of myositis ossificans resulting from a previous intralesional biopsy. Histologic findings included an unusual marrow infiltration by the tumor. The patient was treated with wide resection and has no evidence of local recurrence or distant spread of disease 18 months later.
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PMID:Clear-cell chondrosarcoma. An unusual case complicated by a microinfiltrative pattern of bone marrow involvement and postsurgical myositis ossificans. 319 23

Radiology in a patient with non-traumatic myositis ossificans produced standard images suggestive of juxta-cortical osteosarcoma, the peripheral form of a chondrosarcoma or a synovial sarcoma. Ultrasound failed to provide a conclusive diagnosis, and a scan was the only means of suggesting the benign nature of the lesion by demonstrating integrity of bony cortex and characteristic disposition of calcifications.
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PMID:[Non-traumatic myositis ossificans. Ultrasonic and x-ray computed tomographic aspects. Apropos of a case]. 390 Mar 74

Malignant fibrous histiocytoma of soft tissues (MFH), a mesenchymal tumor of varied morphologic patterns and cell types, sometimes contains bone and cartilage. Such bony and cartilaginous elements in a pleomorphic MFH may pose a difficult diagnostic challenge. An MFH with bone and cartilage can be distinguished from extraosseous osteogenic sarcoma and chondrosarcoma on the basis of qualitative and quantitative features of the osseous and chondroid elements. Five cases of soft tissue MFH containing bone and cartilage reported here showed: 1) that the bony and cartilaginous elements are mostly metaplastic and tend to be in the pseudo-capsule or fibrous septa of the tumor; and 2) that the bony elements may show a zoning pattern with peripheral maturation similar to myositis ossificans. In a single case, there was a small amount of "tumor osteoid." However, this was focal and lacked the diffuse and finely divided or ribbon-like pattern generally associated with osteogenic sarcoma. The probability that MFH with bone and cartilage is less aggressive than soft tissue osteogenic sarcoma or chondrosarcoma underscores the importance of accurate histologic diagnosis of these tumors.
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PMID:The significance of bone and cartilage formation in malignant fibrous histiocytoma of soft tissue. 627 50

The value of new morphologic methods in the diagnosis of bone tumors is demonstrated in a number of cases. In round cell malignancies (Ewing's sarcoma, malignant lymphoma, neuroblastoma, and anaplastic plasmacytoma) diagnostic accuracy can be improved by electron microscopic and immunohistochemical techniques. New methods are also of value in differentiating the metastatic carcinoma from malignant bone primaries. Electron microscopy may show epithelial cell features (ie, gland structures, desmosomes, and tonofilaments), while immunohistologic investigation of the cytoskeleton may facilitate differentiation of epithelial cells (positive for prekeratin) from mesenchymal cells (positive for vimentin). In the differential diagnosis of typical bone tumors, however, such as osteosarcoma, chondrosarcoma, and malignant fibrous histiocytoma, the value of enzyme histochemical, electron microscopic, and immunohistochemical methods appears somewhat restricted: alkaline phosphatase activity may be increased in both chondrosarcoma and osteosarcoma; collagen type II, the cartilage-specific collagen, is found not only in chondrosarcoma but in osteosarcoma as well. Moreover, osteosarcomas may contain a considerable number of macrophages and histiocytes, and so this feature is worthless in distinguishing osteosarcoma from malignant fibrous histiocytoma. A new approach for appraising the malignancy of bone tumors may be through flow cytometric investigation of nuclear DNA content. Osteosarcomas reveal DNA aneuploidies in more than 80% of cases, with a large proportion of cells in the S phase. These features may prove valuable for discerning osteosarcoma from myositis ossificans. In contrast to typical giant cell tumor of bone, a rare case of malignant giant cell tumor showed aneuploid cell lines indicating the malignant nature of the tumor.
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PMID:New cytomorphologic methods in the diagnosis of bone tumors: possibilities and limitations. 660 Jan 11

We discuss a patient with an occult, densely calcified synovial sarcoma of the hip who came to clinical attention because of pulmonary metastases. When synovial sarcomas present with dense and conglomerate calcification, they may be confused with benign processes such as myositis ossificans or tumoral calcinosis. Malignancies such as extraskeletal osteogenic sarcoma, extraskeletal chondrosarcoma, and mesenchymal chondrosarcoma must also be considered in the differential diagnosis.
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PMID:Case report 878: Densely calcifying synovial sarcoma of the hip metastatic to the lungs. 788 82

Extraskeletal osseous and cartilaginous tumors and tumorlike conditions of the extremities can often be differentiated radiologically; for those that cannot, knowledge of the spectrum of lesions will allow a suitably ordered differential diagnosis. Of the osseous lesions--myositis ossificans, fibro-osseous pseudotumor, fibrodysplasia ossificans progressiva, soft-tissue osteoma, and extraskeletal osteosarcoma--all but myositis ossificans are relatively rare. Myositis ossificans has a distinct mineralization pattern that can be observed radiologically as a peripheral rim of lamellar bone. Fibro-osseous pseudotumor typically occurs in the digits of the hand and lacks the well-defined zoning pattern of myositis ossificans. The cartilaginous entities include the true tumors, soft-tissue chondroma and extraskeletal chondrosarcoma, and the tumorlike process, synovial osteochondromatosis. The tumors are relatively rare; synovial osteochondromatosis commonly affects middle-aged men, especially in the knee, and is associated with osteoarthritis. The differential diagnosis for these extraskeletal osseous and cartilaginous lesions includes soft-tissue sarcoma, benign mesenchymoma, malignant mesenchymoma (rare), calcified tophi in gout, melorheostosis (rare), pilomatricoma (rare), and tumoral calcinosis (rare).
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PMID:From the archives of the AFIP. Extraskeletal osseous and cartilaginous tumors of the extremities. 835 73

Alterations of tumour suppressor genes are considered crucial steps in the development of human cancers. Expressions of p53 protein, a product of the tumour suppressor gene altered most commonly in human cancers examined so far, were investigated immunohistochemically in 18 osteosarcomas and 40 other malignant and benign lesions of bone. A monoclonal antibody clone PAb240, which recognizes a common conformational epitope of mutant p53 proteins, stained nuclei of tumour cells in 12 of 18 osteosarcomas (67%). Six tumours (33%) particularly showed positive immunoreactions in more than half of the tumour cells. PAb240 also stained tumour cells in a small number of other malignant bone tumours, such as malignant fibrous histiocytoma, chondrosarcoma, and Ewing's sarcomas. Furthermore, a small number of cells of giant-cell tumours were positively stained. In contrast, PAb240 was completely negative in 21 benign bone tumours and reactive lesions examined. Another monoclonal antibody clone PAb1801, which reacts with both wild- and mutant-type p53 protein, reacted in nuclei of tumour cells of 7 osteosarcomas (39%). Most of those also reacted with PAb240. PAb1801 was expressed much more frequently in other malignant bone tumours and giant-cell tumours. In addition, PAb1801 showed intranuclear positive reactions in tumour cells of a benign chondroblastoma, and reactive cells such as actively proliferating preosteoblasts in a myositis ossificans and osteoclast-like giant cells in a giant-cell tumour. The immunoelectron-microscopic observation that p53 protein was localized in euchromatic areas of nuclei of osteosarcoma cells supported the specificity of immunoreaction for p53 protein, indicating an active role of p53 protein in the regulation of DNA synthesis and transcription. These findings suggest that point mutation of the p53 gene is frequently involved in the development of osteosarcomas. PAb240 may be a useful tool not only in screening point mutations of the p53 gene in osteosarcomas but also in the differential diagnosis between osteosarcomas and reactive bone-forming lesions. Expressions of mutant p53 protein were not correlated with any clinical or pathological factors examined, although the results should be confirmed in studies of a large number of osteosarcomas.
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PMID:Analysis of mutant P53 protein in osteosarcomas and other malignant and benign lesions of bone. 841 91

A case of myositis ossificans in 15-year old boy that occurred as a complication of the recurrent synovia hemangioma of the left knee was presented. The alteration was diagnosed as: osteosarcoma, chondrosarcoma and chondromyxoid fibroma by the pathologists from other institutions. The diagnosis of myositis ossificans was established using numerous histochemical and immunochemical methods (PAS, PAS diastasis, Alcian blue, Masson trichrom, von Kossa, Azur A, Toluidin blue, Goldner, method by Peris, Citokeratin, S-100, NSE and Vimentin). The presence of zonal phenomenon, as the one observed in the presented case, is one of the most significant criteria for differentiation of myositis ossificans from osteosarcoma.
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PMID:[Myositis ossificans in recurrent synovial hemangioma of the knee]. 1083 65

The expression of alpha smooth muscle actin, muscle specific actin, desmin, h-caldesmon, and calponin was studied immunohistochemically in the following soft tissue and bone tumours and tumour-like lesions: muscle fibromatosis, inflammatory pseudotumours, chondroblastoma, enchondroma, chondrosarcoma, fibrous dysplasia, ossifying myositis, osteoblastoma, convential osteosarcoma, leiomyoma and leiomyosarcoma. Tumours and tumour-like lesions with myofibroblastic cells, osteoblasts and chondroblasts frequently exhibited intensive immunoreactivity for the muscle markers, and therefore, some of them may occasionally be confused with leiomyoma and leiomyosarcoma. Calponin does not help to differentiate various mesenchymal tumours expressing muscle markers, because it also stains intensively myofibroblasts, osteoblasts and chondroblasts. We confirmed that h-caldesmon was expressed intensely in leiomyomas and leiomyosarcomas, and never in the other tumours examined, with the exception of three chondroblastomas. The results have shown that h-caldesmon is a rather specific and sensitive marker for smooth muscle tumours, but it can also stain some actin positive myochondroblasts. It is possible that the positivity of h-caldesmon in some chondroblastomas is due to their complete myogenic transdifferentiation, and so we use the term myochondroblasts and myochondrocytes for designation of such S-100 protein, actin, and h-caldesmon positive cells.
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PMID:[Immunohistochemical differentiation of leiomyocellular tumors and tumors with myogenic differentiation]. 1287 3

Periosteal osteoblastoma is an extremely rare bone-forming neoplasm located on the surface of cortical bone. Of the fewer than 30 cases of periosteal osteoblastomas found in the literature, 2 have been reported to be located in cranial bone, and these have not been documented in detail with clinical history, radiographic findings, macroscopic features, and microscopic findings. Although the differential diagnoses of periosteal lesions include parosteal and periosteal osteosarcoma, periosteal chondroma and chondrosarcoma, osteochondroma, osteoid osteoma, periostitis ossificans, and myositis ossificans, an important differential diagnosis both radiologically and pathologically of such a lesion in the cranium is meningioma. We report an unusual case of periosteal osteoblastoma located in the frontal cranial bone that was radiologically consistent with a meningioma. The differential diagnosis of metaplastic meningioma with differentiation toward bone is discussed.
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PMID:A rare case of periosteal osteoblastoma located in the frontal cranial bone. 1591 30


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