1,721,034 research outputs found
Clinicopathological features, diagnosis and treatment of clear cell sarcoma/melanoma of soft parts
No full textBackground: Clear cell sarcoma of tendons and aponeuroses is a rare, high grade malignant soft tissue tumor resembling melanoma and soft tissue sarcomas. Clinical and Imaging Presentation: The median age at presentation is 27 years and the most common location are the foot and the ankle. MR imaging typically shows a benign looking, well defined, homogenous mass; on T1-weighted MR images, it is usually homogeneous and isointense or slight hyperintense to muscle, whereas on T2-weighted MR images, it is usually more heterogeneous with variable signal intensity. Pathology: Microscopically, the clear cell appearance is due to the accumulation of glycogen. The cells show no or minimal pleomorphism, and paucity of mitotic figures that is in concordance with the slow-growing behavior of the tumor. Scattered multinucleated giant cells are commonly present; areas of necrosis and melanin pigment may be identified. The reciprocal translocation t(12;22)(q13;q12) is observed in more than 90% of clear cell sarcoma cases. In addition, polysomy of chromosome 8 has been observed as a secondary abnormality in many cases of clear cell sarcoma. The differential diagnosis of clear cell sarcoma should include melanoma, epithelioid malignant peripheral nerve sheath tumor, melanotic schwannoma, paraganglioma-like dermal melanocytic tumor, perivascular epithelioid cell neoplasms (PEComas), cellular blue naevus, synovial sarcoma (monophasic type), alveolar soft part sarcoma, paraganglioma, epithelioid sarcoma and carcinomas. Treatment and Prognosis: The treatment of choice for clear cell sarcoma is wide surgical resection. If complete excision is achieved, adjuvant treatments are not unnecessary. Chemotherapy is predominantly employed in patients with metastatic disease. The 5 to 20 year survival of the patients with clear cell sarcoma range from 67% to 10%. The rates of local recurrence ranges up to 84%, late metastases up to 63%, and metastases at presentation up to 30%
Current treatment considerations for osteosarcoma metastatic at presentation
No full textApproximately one-fourth of osteosarcoma patients have metastases at presentation. The best treatment options for these patients include chemotherapy, surgery, and radiotherapy; however, the optimal scheme has not yet been defined. Standard chemotherapy for osteosarcoma metastatic at presentation is based on high-dose methotrexate, doxorubicin, and cisplatin (the MAP regimen), with the possible addition of ifosfamide. Surgical treatment continues to be fundamental; complete surgical resection of all sites of disease (primary and metastatic) remains essential for survival. In patients whose tumors do not respond to neoadjuvant chemotherapy, early surgical resection of the primary tumor with limb-salvage surgery or amputation and multiple metastasectomies, if feasible, after the completion of adjuvant chemotherapy is a reasonable option, as the reduction of the tumor volume could probably increase the effect of chemotherapy. Advanced radiotherapy techniques, such as carbon ion radiotherapy and stereotactic radiosurgery, and molecular targeted chemotherapy with drugs such as pazopanib or apatinib have improved the dismal prognosis, especially for patients who are medically inoperable or who refuse surgery. Given that the presence of metastatic disease at diagnosis of a patient with osteosarcoma is a poor prognostic factor, a multidisciplinary approach by surgeons, medical oncologists, and radiotherapists is important
Humeral fracture between a total elbow and total shoulder arthroplasty
No full textThis article presents a case of a 71-year-old woman with a humeral fracture between a cementless reverse total shoulder arthroplasty and a cemented total elbow arthroplasty and discusses our treatment plan. Surgical treatment was performed after the patient was informed of possible complications and the benefits of surgery including: early, complete restoration of arm anatomy, greater functional improvement of the adjacent joints, and increased risk of nonunion with nonoperative treatment. The fracture was comminuted and extended proximally around the shoulder prosthesis. Through the posterior approach, the radial nerve was identified and protected. Both prostheses were found firmly fixed to bone. The fracture around the shoulder prosthesis was reduced first using a strut allograft and reduction clamps. Next, arm alignment restoration and distal humerus reduction were performed. The construct was neutralized with a 3.5-mm locking plate spanning the whole length of the humerus. The locking plate was positioned posterolaterally and the strut medially in a 90° to 90° configuration secured with wires and cables. A hinged elbow brace was applied for 6 weeks postoperatively. Active range of motion exercises of the wrist and hand and passive motion of the elbow and shoulder were started at 4 to 5 days postoperatively. At 2 weeks postoperatively, passive motion of the elbow and shoulder progressed to strengthening exercises. Thereafter, the patient underwent several weeks of physical therapy to restore motion, strength, and function of the upper extremity with instructions not to overload the arm and avoid heavy work and sports for as long as 1 year. At 10 months postoperatively, radiographs of the arm showed a stable construct; the patient had resumed full activities of daily living
Intercalary reconstruction following resection of diaphyseal bone tumors: A systematic review
No full textIntroduction: The options for the reconstruction of diaphyseal defects following the resection of bone tumors include biological or prosthetic implants. The purpose of our study was to evaluate different types of intercalary reconstruction techniques, including massive bone allograft, extracorporeal devitalized autograft, vascularized free fibula, and modular prosthesis. Methods: We performed a systematic review of articles using the terms diaphyseal bone tumor and intercalary reconstruction. All the studies reporting the non-oncological complications such as infection, nonunion and fracture of the intercalary reconstructions were included. We excluded articles published before 2000 or did not involve humans in the study. Case reports, reviews, technique notes and opinion articles were also excluded based on the abstracts. Thirty-three articles included in this review were then studied to evaluate failure rates, complications and functional outcome of different surgical intercalary reconstruction techniques. Results: Nonunion rates of allograft ranged 6%–43%, while aseptic loosening rates of modular prosthesis ranged 0%–33%. Nonunion rates of allograft alone and allograft with a vascularized fibula graft ranged 6%–43% and 0%–33%, respectively. Fracture rates of allograft alone and allograft with a vascularized fibula graft ranged 7%–45% and 0%–44%, respectively. Infection rates of allograft alone and allograft with a vascularized fibula graft ranged 0%–28% and 0%–17%, respectively. All of the allograft (range: 67%–92%), extracorporeal devitalized autograft including irradiation (87%), autoclaving (70%), pasteurization (88%), low-heat (90%) or freezing with liquid nitrogen (90%), and modular prosthesis (range: 77%–93%) had similar Musculoskeletal Tumor Society functional scores. Addition of a vascularized fibula graft to allograft did not affect functional outcome [allograft with a vascularized fibula graft (range: 86%–94%) vs. allograft alone (range: 67%–92%)]. Conclusion: Aseptic loosening rates of modular prosthesis seem to be less than nonunion rates of allograft. Adding a vascularized fibula graft to allograft seems to increase bone union rate and reduce the risk of fractures and infections, though a vascularized fibula graft needs longer surgical time and has the disadvantage of donor site morbidity. These various intercalary reconstruction techniques with or without a vascularized fibula autograft had similar functional outcome
Clinical out come in central conventional chondrosarcoma of bone. Analysis of 296 cases
No full textClinical out come in central conventional chondrosarcoma of bone. Analysis of 296 case
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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