1/28. Parosteal osteosarcoma of the ring finger metacarpal in a semi-professional pianist. We report treatment of a low grade parosteal osteosarcoma of the ring finger metacarpal in a patient who would not contemplate ray amputation because of her career. Surgery involved excision of the bone, extracorporeal radiation then re-implantation. ( info) |
2/28. Juxtacortical osteosarcoma. A distinct malignant bone neoplasm. The purpose of this report is the study of a malignant bone tumor of similar histological picture with conventional (intramedullary) osteosarcoma. Contributing factors in the study of juxtacortical osteosarcoma are the clinical, X-ray and histologic pictures. A case of parosteal osteosarcoma in a 28-year-old male is reported. In conjuction with X-ray findings we review the histological characteristics of the tumor through serial sections of the peripheral, central and parosteal parts and the findings are described in detail. In addition to the histological findings, differential diagnosis and prognosis are also discussed. From the general study of the tumor it has been shown that juxtacortical osteogenic sarcoma behaves differently in contrast to classic osteosarcoma, depending on the degree of differentiation of the tumor. ( info) |
3/28. Telangiectatic dedifferentiation of a parosteal osteosarcoma. A unique case of parosteal osteosarcoma (POS) of the proximal femur, with areas of telangiectatic dedifferentiation, in a 28-year-old woman is reported. The patient had a 7-week history of pain and swelling in her right thigh. A biopsy diagnosis of POS was established. The patient was treated with two cycles of intraarterial chemotherapy, followed by limb salvage surgery. Histological examination of the resected specimen showed POS with areas of dedifferentiation composed of highgrade telangiectatic osteosarcoma with associated secondary aneurysmal bone cyst change. ( info) |
4/28. Juxtacortical osteogenic sarcoma of mandible. A case report. Juxtacortical osteogenic sarcoma of bone is a relatively uncommon form of osteogenic sarcoma. In the jaw bones, it is extremely rare. Here, we present a case of Juxtacortical Osteogenic Sarcoma of mandible in a 45 year old man which presented as an epulis in the mandibular incisor region. ( info) |
5/28. Two unusual osteogenic orbital tumors: presumed parosteal osteosarcomas of the orbit. OBJECTIVE: To report two cases of suspected parosteal osteosarcoma of the orbit, with dedifferentiation into a high-grade liposarcoma occurring in one patient. DESIGN: Two retrospective case reports. methods: The clinical, radiologic, and pathologic records of two patients with suspected orbital parosteal osteosarcoma were retrospectively reviewed. MAIN OUTCOME MEASURES: Histologic evaluation and clinical follow-up were measured. RESULTS: The first patient was a 47-year-old male presenting with a 5-month history of painless right lower lid swelling; excision biopsy suggested a well-differentiated parosteal osteosarcoma of the orbital floor, which recurred 3 years later. Six months after excision of the recurrence, the mass demonstrated accelerated growth, and a lid-sparing exenteration was performed; histologic examination showed a high-grade liposarcoma. The patient remains disease-free at 4 years. The second patient, a 40-year-old male, presented with an 8-year history of proptosis and a right superotemporal orbital mass. The mass was excised completely at lateral orbitotomy; histologic examination suggested a well-differentiated parosteal osteosarcoma. The patient remains well 9 months postoperatively. CONCLUSIONS: Parosteal osteosarcoma is an uncommon tumor, usually affecting long bones, that is extremely rare in the orbit. It is a low-grade sarcoma that tends to recur locally after excision but has a favorable prognosis. Dedifferentiation into a high-grade sarcoma occasionally occurs in parosteal osteosarcoma, but transformation into liposarcoma does not seem to have been previously reported. It is important to recognize dedifferentiated parosteal osteosarcoma, because the prognosis is poor, and radical treatment may be required. ( info) |
6/28. The role of imaging modalities in the diagnosis of primary dedifferentiated parosteal osteosarcoma. Dedifferentiated parosteal osteosarcoma (dd-POS) is defined as high-grade sarcomatous components coexisting with low-grade POS components. With regard to the histological diagnosis of dd-POS, the sampling of a small area of dedifferentiation through the densely mineralized POS can be a problem. In this situation, imaging is important to identify the area with the highest possibility of dedifferentiation. We report a patient in whom dedifferentiation was shown by computed tomography (CT) and magnetic resonance imaging (MRI). CT revealed a radiolucency in a highly mineralized area. T2-Weighted MRI showed a relatively high signal intensity, corresponding to the radiolucency, surrounded by a very low signal intensity area. Furthermore, gadolinium-enhanced T1-weighted MRI showed marked enhancement. Based on these imaging techniques, the condition was diagnosed as most likely to be a dd-POS, although a representative sample was not accessible by incisional biopsy. Neoadjuvant chemotherapy was administered, followed by wide resection and adjuvant chemotherapy. Four years after the surgery, partial lobulectomy was required because of a pulmonary metastasis. Three years after the second surgery, the patient remained well without evidence of metastases. Based on the initial diagnosis and, consequently, the optimal treatment of combined chemotherapy and wide resection, our patient showed a good clinical outcome. ( info) |
| The authors report the case of a 50-year-old man who presented with nontraumatic swelling of the left upper arm. The diagnosis of parosteal osteosarcoma of the humerus was made after diagnostic workup. A long diaphyseal segment of the humerus containing the tumor was resected with a healthy margin of soft tissues and was irradiated extracorporeally with a single dose of 30 Gray. The bony segment was then reimplanted after removal of the tumor using plate and screw fixation. Loosening of the proximal screws after one year required additional fixation and autologous cancellous bone grafting. The patient has a nearly three-year-follow-up and there are no signs of tumor recurrence or metastasis. The proximal osteotomy has healed nicely; the distal fixation osteotomy exhibits delayed healing. The pathogenesis of parosteal osteosarcoma is discussed. ( info) |
| Parosteal osteosarcoma of the skull is a distinct surface bone tumor, with a better prognosis than conventional osteosarcoma. The most common location is on the surface of the distal femur which accounts for 46-66% of the cases. The presentation in the skull is uncommon and there are few cases reported in the literature. We describe the case of a man who developed a parosteal osteosarcoma arising from the occipital bone with extension to the parietal bone. The patient was operated and had a complete tumor resection. ( info) |
9/28. Juxtacortical osteoma of the ulna. Acase of juxtacortical osteoma of the ulna in a 47-year-old woman is presented. She had a dense bony mass on the ulna. Radiological examinations (plain radiography, computed tomography, magnetic resonance imaging) strongly suggested a rare case of juxtacortical osteoma of a long tubular bone. The differential diagnosis included parosteal osteosarcoma, melorheostosis, osteochondroma, end-stage juxtacortical myositis ossificans, and fibrous dysplasia protuberans. The tumor was excised totally for thorough pathological examination, which revealed it to be composed of lamellar bone, suggesting that the origin was periosteal. ( info) |
10/28. Parosteal osteosarcoma with myocardial metastasis 13 years after follow-up. PURPOSE: To report the case of a woman with a diagnosis of grade II (low grade) parosteal osteosarcoma with the occurrence of myocardial metastasis 13 years after resection, and to present a review of the existing literature on the subject. methods: Description of the case and review of the literature. CONCLUSION: The review leads to the conclusion that the occurrence of metastasis from parosteal osteosarcoma can occur in up to 38% of the cases, in spite of its relatively low aggressiveness. However, myocardial metastasis of a parosteal osteosarcoma is an event that was not found in the literature. ( info) |