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Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bone remodeling in pathologic conditions was studied with the scanning electron microscope (SEM). Benign and malignant ossification were examined in cases of myositis ossificans, ossifying fibroma, osteoid osteoma, and osteosarcoma, Resorption of bone due to invasion by non-ossifying tumors was found in cases of squamous cell carcinoma, adenocarcinoma, ameloblastoma, and multiple myeloma. Bone formation due to excessive production of growth hormone was studied in a case of acromegaly. Resorption of bone due to pathologic processes resembled the pattern found in surfaces which were undergoing resorption by osteoclasts. Lamelar-cortical bone formation in acromegally was similar in nature to normal bone. The deformities were rleated to the excessive continuous osteogenesis that occurs in these instances. Neoplastic ossification was characterized by calcifying globules, the diameters of which ranged from 1 to 3 micron. The surfaces of these globules were constructed of minute calcospherites with diameters ranging from 0.1 to 0.3 micron. It is suggested that the pattern of globular calcification is similar to the type that was found with the SEM in fetal bone and cartilage, during healing of fractured bone, and also with the TEM in normal and pathologic calcification.
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PMID:Bone remodeling in pathologic conditions. A scanning electron microscopic study. 26 94

Myositis ossificans circumscripta is the heterotopic formation of nonneoplastic bone and cartilage in soft tissue. These benign lesions can mimic more serious lesions, both radiographically and histopathologically. Recognition of the benign character of myositis ossificans is imperative in order to avoid mutilating surgical procedures. Five cases are presented with emphasis on angiographic signs which differentiate this lesion from histopathologically similar lesions. Three of these are illustrated, along with an example of an osteosarcoma for comparison. The angiographic manifestations of myositis ossificans differ in the various phases of the disease. In the active stage, the lesions have numerous fine vessels causing a diffus stain. Malignant tumors such as osteosarcoma, extraosseous osteosarcoma, and fibrosarcoma, which are included in the differential diagnosis, often present clearly defined pathologic vessels as well as arteriovenous shunts, venous lakes, amputated vessels, invasion of large arteries and veins, and large abnormal draining veins. In the healing stage, the lesions are usually avascular, and there is no difficulty in differentiating this condition from malignant bone lesions with the sole exception of well differentiated parosteal osteosarcomas. In these cases, the plain radiographic features are most important in arriving at the correct diagnosis.
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PMID:Myositis ossificans: diagnostic value of arteriography. 40 7

Eight cases of pseudomalignant myositis ossificans are presented. There was a male predominance and four patients were under 20 years of age. There was no history of trauma, but there was evidence of mild local or general inflammation with positive roentgenograms in two cases. Histologically there was active fibroblastic proliferation, appearing to develop essentially in fibrin deposits with metaplasia leading to the formation of an unusual osteoid. The newly formed mass was surrounded by bone and compressed the surrounding muscle fibers, which were either atrophic or trapped therein. The histological criteria distinguishing this disorder from other forms of myositis ossificans are discussed, and comparisons are drawn with nodular fascitis and proliferative myositis. An association with the latter was observed in one case. This nontumourous growth must be distinguished from osteogenic sarcoma of soft tissue. The differential diagnosis is based on careful histological criteria, which must be supported by clinical and radiological data.
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PMID:Pseudomalignant myositis ossificans. A pathological study of eight cases. 118 91

Lymphoma can involve any part of the musculoskeletal system. Primary musculoskeletal lymphoma is rare but can occur in bone (reticulum cell sarcoma) or in the skin and subcutaneous tissues (mycosis fungoides). Secondary involvement in the musculoskeletal system is more common and can have a variety of radiologic findings. The definitive diagnosis of musculoskeletal lymphoma, however, is difficult to make by using imaging criteria alone. Any part of the musculoskeletal system can be involved and, therefore, a wide variety of primary and secondary neoplasms or inflammatory processes may have similar radiologic findings. The main differential diagnostic considerations, depending on the age of the patient and the clinical presentation, include osteosarcoma, Ewing's tumor, metastatic disease (from breast, lung, thyroid, or renal primary lesions), as well as chronic osteomyelitis or myositis. Primary and secondary bone lymphoma can be indistinguishable radiologically and histologically, but modern imaging techniques allow more accurate differentiation of primary from secondary bone involvement. This pictorial essay illustrates the CT findings of primary and secondary lymphoma involving bone, muscle, and skin and subcutaneous tissues.
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PMID:Lymphoma of bone, muscle, and skin: CT findings. 837 91

Heterotopic ossification (myositis ossificans) is usually a posttraumatic reactive process involving new bone formation. This nonneoplastic process can be clinically and radiologically confused with osteosarcoma. A case of heterotopic ossification is reported in which cytologic material was obtained from a partially calcified thigh mass from a 17-year-old, athletic male. Aspiration cytology revealed numerous osteoclastic giant cells containing multiple plump nuclei. These cells were admixed in a benign-appearing stromal background composed of mature fibroblasts and were typified by elongated spindle cells. A small incisional biopsy showed new bone formation, osteoclasts, osteoblasts and fibroblasts consistent with maturing heterotopic ossification. Heterotopic ossification may be distinguished cytologically from osteosarcoma by the presence of numerous uniform benign stromal cells composed of mature fibroblasts and osteoclastic giant cells. The differential diagnosis may be more difficult in the early stages of this reactive and proliferative process. Adequate sampling of suspected heterotopic ossification by aspiration cytology may avoid surgery in a selected group of patients.
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PMID:Aspiration cytology of heterotopic ossification. A case report. 154 99

A case of paravertebral, non-traumatic myositis ossificans in a 4.5 year-old boy is reported. Infectious spondylitis and osteosarcoma were considered before the diagnosis was established on the basis of histological examinations of a biopsy performed during excision. A group G beta hemolytic streptococcus was isolated from the biopsy, suggesting an infectious etiology which has rarely been reported. The child appears to be completely cured one year after excision.
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PMID:[Circumscribed spinal myositis ossificans of infections origin]. 215 45

Tumors are rare causes of knee symptoms in children but must be considered in the differential diagnosis of pediatric knee pain in order to avoid errors in treatment that could result in loss of limb or even life. Experience with 199 bone and soft-tissue tumors about the knee in children are reviewed. The majority of lesions were benign bone tumors (n = 101), with osteocartilaginous exostoses, nonossifying fibromas, and chondroblastomas predominating. Malignant bone tumors (n = 59) were less frequent, and osteosarcoma (n = 48) was by far the most common sarcoma. Soft-tissue lesions (n = 31) were much less frequent and included rhabdomyosarcoma, synovial sarcoma, fibrosarcoma, and desmoid tumors. A careful history, physical examination, and review of roentgenograms are essential to avoid errors in diagnosis. Malignant tumors require roentgenograms and laboratory studies in sequence to stage the patient. A properly performed biopsy established the diagnosis in most instances. Popliteal cysts, stress fractures, infection, myositis ossificans, histiocytosis, and other lesions can mimic tumors and delay correct diagnosis.
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PMID:Tumors about the knee in children. 218 35

Three cases of benign soft tissue osteochondroma, a lesion of uncertain pathogenesis, are reported. Two cases were located in the subcutaneous tissues beneath the calcaneus. The other was located in the soft tissues near the left ankle joint. The diagnosis of soft tissue osteochondroma should be considered when a well-defined osseous mass is located in the soft tissues. The differential diagnosis includes myositis ossificans, tumoral calcinosis, synovial chondromatosis, and soft tissue osteosarcoma.
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PMID:Soft tissue osteochondroma. A report of three cases. 281 52

We report heterotopic chondro-ossification occurring in the hand of a young man in the absence of trauma. The differential diagnosis includes: bizarre periosteal osteochondromatous proliferations of the hands and feet, mature lesions of myositis ossificans, osteogenic sarcoma, confluent lesions of extra-articular synovial chondromatosis, and nodular forms of florid periostitis. True heterotopic bone formation is a benign condition, which of itself requires no specific treatment.
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PMID:Heterotopic chondro-ossification: a case report. 295 78

Eight cases are described of circumscribed heterotopic ossification in the soft tissues characterised by spontaneous onset, no history of trauma, and rapid course which have frequently led to a mistaken preoperative diagnosis of highly malignant tumour. The terminology differentiates it from myositis ossificans, which is a different entity. The authors emphasize the need for accurate evaluation of all the clinical and radiographic data in order to avoid an erroneous diagnosis of extraosseous osteogenic sarcoma or parosteal osteogenic sarcoma. In this regard, both radiography and histological examination demonstrate the so-called zoning pattern, namely a radiolucent central zone corresponding to the more immature area and consisting of fibrous tissue with active histiofibroblastic proliferations and a radiopaque peripheral area, where ossification is more mature the closer it gets to the periphery. Histological specimens obtained exclusively from the central area may lead even the most expert pathologists to a diagnosis of fibrosarcoma or osteogenic sarcoma. Finally, the pathogenetic aspects of the anomaly are discussed, as well as those concerned with the differential diagnosis from other types of heterotopic ossification.
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PMID:Circumscribed spontaneous heterotopic ossification in the soft tissues simulating sarcoma. 313 37


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