1/1364. 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. ( info) |
2/1364. 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. ( info) |
3/1364. Establishment and characterization of a second primary osteosarcoma cell line (OSrb/N-M) from a patient cured of bilateral retinoblastoma. A cell line, designated OSrb/N-M, was established from the second primary osteosarcoma that developed in a 17-year-old Japanese female patient who had suffered from bilateral retinoblastoma at infancy. The OSrb/N-M cells grew as an adherent monolayer and retained some osteogenic biochemical phenotypes. In cytogenetic analyses, this cell line revealed many structural and numerical abnormalities, however, the bands q14 of both chromosomes 13 appeared to be normal, whereas the constitutional cells displayed normal female karyotypes. Immunoblot studies using monoclonal antibodies specific to RB protein demonstrated that the tumor cells did not express RB protein, suggesting that the OSrb/N-M cells might suffer from a loss-of-function mutation at this gene locus. Thus, this cell line is useful to study the molecular mechanism for the tumorigenesis of osteosarcoma with regard to an association with retinoblastoma. ( info) |
4/1364. 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. ( info) |
5/1364. Bizarre parosteal osteochondromatous proliferation in the anterior maxilla: report of a case. Bizarre parosteal osteochondromatous proliferations are a rare subgroup of the osteochondromatous lesions. They must be differentiated from reactive osteochondromatous proliferations, low grade parosteal osteogenic sarcoma, and chondrosarcoma. Their recognition is important from the point of view of management, which should be by simple excision. This article describes a case of bizarre parosteal osteochondromatous proliferation in a 2-year-old child; the lesion developed in the anterior maxilla, a previously unreported site. ( info) |
| We report a case of small cell osteosarcoma arising in the distal ulna. The radiologic and pathologic features of this histologic variant of osteosarcoma that allow differentiation from other lytic lesions with small round cells are discussed. ( info) |
7/1364. 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. ( info) |
8/1364. 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. ( info) |
9/1364. Malignant phyllodes tumor with chondrosarcomatous differentiation: report of a case with cytological presentation. Malignant phyllodes tumor is a rare breast tumor with neoplastic epithelial and stromal components. The stromal component may show homologous and heterologous sarcomatous elements, including chondrosarcomatous and osteosarcomatous differentiation. Because these tumors may present with an almost exclusively sarcomatous component, it is important for the pathologist to include this entity in the diagnostic considerations of fine-needle aspirations of breast neoplasms showing sarcomatous differentiation. Following surgical excision, careful examination of the gross specimen and thorough sampling of the specimen is recommended before rendering a definitive histologic diagnosis. We describe the cytologic and histologic findings in a case of malignant phyllodes tumor with sarcomatous overgrowth showing predominantly chondrosarcomatous differentiation. ( info) |
10/1364. Delayed methotrexate clearance in a patient with sickle cell anemia and osteosarcoma. A 15-year-old girl with homozygous sickle cell anemia (HbSS) and osteosarcoma is described. Delayed clearance of methotrexate (MTX) after the second course of high-dose MTX (HDMTX) led to the development of renal and hepatic toxicities. Rescue was accomplished with high-dose leucovorin, intravenous carboxypeptidase G2, and thymidine. Although the renal and hepatic abnormalities resolved, focal tonic-clonic seizures developed, accompanied by abnormal brain imaging. Four weeks after this episode, all clinical and biochemical abnormalities resolved. Preexistent end-organ damage associated with HbSS may compromise the ability to deliver high-dose chemotherapy with curative intent in patients with malignant disease. ( info) |