1/496. Multifocal osteosarcoma: an unusual presentation.PURPOSE: Report the unusual presentation, clinical course, and cytogenetic abnormalities in a child with multifocal osteosarcoma. patients AND methods: A 10-year-old boy had multifocal osteosarcoma involving the entire skeleton, pleura, bone marrow, and lungs. He had marked anemia, thrombocytopenia, and severe hypocalcemia at diagnosis. RESULTS: Despite aggressive chemotherapy, he died from progressive disease 1 month after diagnosis. cytogenetic analysis of tumor cells within the pleural fluid showed multiple chromosomal abnormalities with amplification of the c-myc oncogene. CONCLUSION: Multifocal osteosarcoma should be considered in the differential diagnosis of a child with pancytopenia and multiple bone lesions. Amplification of the c-myc oncogene may have had a significant role in the pathogenesis, etiology, and rapid progression of this patient's multifocal disease. Additional studies will be needed to determine the biologic significance of c-myc amplification in multifocal osteosarcoma.- - - - - - - - - - ranking = 1keywords = bone (Clic here for more details about this article) |
2/496. Intracortical osteoblastic osteosarcoma with oncogenic rickets.Intracortical osteosarcoma is the rarest variant of osteosarcoma, occurring within, and usually confined to, the cortical bone. Oncogenic osteomalacia, or rickets, is an unusual clinicopathologic entity in which vitamin d-resistant osteomalacia, or rickets, occurs in association with some tumors of soft tissue or bone. We present a case of oncogenic rickets associated with intracortical osteosarcoma of the tibia in a 9-year-old boy, whose roentgenographic abnormalities of rickets disappeared and pertinent laboratory data except for serum alkaline phosphatase became normal after surgical resection of the tumor. Histologically, the tumor was an osteosarcoma with a prominent osteoblastic pattern. An unusual microscopic feature was the presence of matrix mineralization showing rounded calcified structures (calcified spherules). Benign osteoblastic tumors, such as osteoid osteoma and osteoblastoma, must be considered in the differential diagnosis because of the relatively low cellular atypia and mitotic activity of this tumor. The infiltrating pattern with destruction or engulfment of normal bone is a major clue to the correct diagnosis of intracortical osteosarcoma. The co-existing radiographic changes of rickets were due to the intracortical osteosarcoma.- - - - - - - - - - ranking = 1.5keywords = bone (Clic here for more details about this article) |
3/496. Differential diagnosis of metastases in bone scans: chemotherapy induced bone necrosis.AIM: Influenced by the incorrect diagnosis of a bone metastasis caused by bone necrosis we evaluated reasons and frequency of bone necrosis in patients referred for bone scanning in follow-up of tumors. methods: Bone scans performed within two years on patients with primary bone tumors or tumors metastatic to bone were reviewed in respect to the final diagnosis bone necrosis. RESULTS: We found the cases of three young patients who presented the appearance of hot spots on bone scintigrams which were finally diagnosed as bone necrosis. In two cases the diagnosis was based on histological findings, in one case the diagnosis was made evident by follow-up. All the three patients had been treated by chemotherapy and presented no other reason for the development of bone necrosis. Enhanced tracer uptake in all sites decreased within eight weeks up to two years without therapy. CONCLUSION: Single and multiple hot spots after chemotherapy may be originated by bone necrosis but mimicry metastases.- - - - - - - - - - ranking = 9.5keywords = bone (Clic here for more details about this article) |
4/496. Pseudosarcoma in Paget's disease of bone.The appearance of a sarcoma of bone is a well-recognized complication of Paget's disease. The most common type of such a sarcoma is osteosarcoma. Much less common are soft tissue lesions adjoining the pagetic bone that clinically and radiologically simulate sarcoma but histologically represent exaggerated periosteal bone formation as a manifestation of the basic pathologic process. We present a case of a bulky juxtacortical soft tissue mass in the thigh arising from a pagetic femur in a 62-year-old patient with polyostotic Paget's disease that was clinically and radiologically suspected to be a juxtacortical osteosarcoma. Microscopically, the lesion showed features of florid Paget's disease without any evidence of sarcomatous growth. It is important to be aware of this rare manifestation of Paget's disease to avoid unnecessary overtreatment.- - - - - - - - - - ranking = 3.5keywords = bone (Clic here for more details about this article) |
5/496. Parosteal osteosarcoma of a metatarsal with intramedullary invasion.A 70-year-old man presented with increasing swelling of 2 years' duration, on the dorsal aspect of the forefoot. Imaging studies revealed a heavily calcified surface lesion of bone with early invasion of the underlying second metatarsal. Both imaging findings and the subsequent resection histology were consistent with a parosteal osteosarcoma, which is particularly rare at this site and at this age. The differential diagnosis of a mineralizing surface lesion of bone arising in the foot is discussed.- - - - - - - - - - ranking = 1keywords = bone (Clic here for more details about this article) |
6/496. Accumulation of methotrexate in human tissues following high-dose methotrexate therapy.methotrexate concentration was analyzed in a number of tissues of a patient of osteogenic sarcoma who had been on high-dose methotrexate therapy for nearly 6 months. Gall bladder and kidney contained the highest concentration of the drug, followed by testis, small intestine, skeletal muscle, bone marrow, lung, spleen, heart and liver. Although, compared to kidney the liver contained relatively small amount of the drug, yet nearly 1/5th of the total drug in liver was in bound form. This bound form of methotrexate is most likely associated with multiple forms of dihydrofolate reductase. The total concentration of methotrexate in kidney is 80 fold higher than the concentration of the drug in liver and 28 fold higher than the concentration in bone marrow. This suggests that in high-dose methotrexate therapy, nephrotoxicity is the more immediate threat to the patient than hepatotoxicity and bone marrow suppression.- - - - - - - - - - ranking = 1.5keywords = bone (Clic here for more details about this article) |
7/496. Small cell osteogenic sarcoma of the ribs: cytological, immunohistochemical, and ultrastructural study with literature review.Small cell osteosarcoma (OS) is a rare variant of OS that is composed of small cells resembling those of Ewing's sarcoma (ES) with recognizable osteoid. This type of tumor often creates difficulty in making a diagnosis when tissue samples do not include osteoid. The frequent sites are long bones and until now there have been no reported cases arising in the ribs. A case is reported here of small cell OS occurring in the ribs of a 37-year-old female with its aspiration cytologic and electron microscopic characteristics. In the cytologic smear, the small round neoplastic cells were individually scattered or arranged in small nests. The nuclei were hyperchromatic and oval with no visible nucleoli. Ultrastructurally, the nuclei had a round or oval euchromatic chromatin pattern and occasional nucleoli. The scanty cytoplasm contained a small quantity of organelles including either tubular or dilated cisternae of RER, a few mitochondria, and free or polyribosomes. Other organelles were absent. Although the electron microscope sample of this case did not include bone mineral (hydroxy apatite), the electron microscopic features of the tumor cells were unique and useful for exclusion of other small round cell neoplasms.- - - - - - - - - - ranking = 1keywords = bone (Clic here for more details about this article) |
8/496. Evaluating marrow margins for resection of osteosarcoma. A modern approach.Intraoperative evaluation of bone marrow margins by frozen section analysis is a common practice in the surgical treatment of osteogenic sarcoma. The purpose of this study was to assess the clinical use of intraoperative marrow margin evaluation to rule out occult intramedullary tumor extension in osteosarcoma surgery. One hundred twenty-eight consecutive patients with high grade osteosarcoma diagnosed between 1988 and 1996 (Group 1) were reviewed retrospectively and compared with 92 consecutive patients treated from 1979 to 1984 (Group 2). Eighty-five patients in Group 1 met the inclusion criteria of having high grade intramedullary lesions of the long bones observed on preoperative magnetic resonance imaging evaluation of the lesion and intraoperative frozen section analysis of the bone marrow margin. Thirty-three patients in Group 2 met the same inclusion criteria with the exception of having preoperative magnetic resonance imaging. Ninety-two marrow margins in Group 1 and 33 marrow margins in Group 2 were evaluated by frozen section. All 92 marrow margins in patients in Group 1 were negative by frozen section analysis and permanent histologic analysis. Of the 33 marrow margins in patients in Group 2, three (9.1%) were reported positive for tumor. Of these, one was found to be a false positive result on permanent pathologic examination. In addition, one false negative frozen section result was found, which was positive for tumor on permanent pathologic examination. The difference in true positive results of marrow margins between Group 1 and Group 2 was statistically significant. Intraoperative marrow margin evaluation by frozen section is not mandatory with modern imaging techniques. Preoperative evaluation of tumor extent using magnetic resonance imaging and intraoperative evaluation of the specimen by the pathologist (done by bivalving the specimen) are reliable methods to ensure adequate surgical margins in most cases of conventional osteosarcoma of the long bones.- - - - - - - - - - ranking = 2keywords = bone (Clic here for more details about this article) |
9/496. osteosarcoma of the metatarsal bone.A case of osteosarcoma arising from a metatarsal bone is reported, focusing on the radiological findings and differential diagnosis.- - - - - - - - - - ranking = 2.5keywords = bone (Clic here for more details about this article) |
10/496. Osteogenic sarcoma with skeletal muscle metastases.Two cases of osteogenic sarcoma with skeletal muscle metastases are described. A 40-year-old woman presented with progressive swelling of both calves and a soft tissue back lump. She had been diagnosed with mandibular chondroblastic osteogenic sarcoma 6 years earlier. Radiographs showed calcified masses. MRI scans and bone scintigraphy revealed multiple soft tissue masses in both calves. Bone scintigraphy also showed uptake in the back lump, right thigh and left lung base. biopsy confirmed metastatic chondroblastic osteogenic sarcoma, which initially responded well to chemotherapy. However, the metastatic disease subsequently progressed rapidly and she died 21 months after presentation. The second case concerns a 20-year-old man who presented with a pathologic fracture of the humerus, which was found to be due to osteoblastic osteogenic sarcoma. He developed cerebral metastases 17 months later, followed by metastases at other sites. Calcified masses were subsequently seen on radiographs of the abdomen and chest. CT scans confirmed the presence of densely calcified muscle metastases in the abdominal wall, erector spinae and gluteal muscles. The patient's disease progressed rapidly and he died 30 months after presentation.- - - - - - - - - - ranking = 0.5keywords = bone (Clic here for more details about this article) |
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