A popliteal giant synovial osteochondroma mimicking a parosteal osteosarcoma
- PDF / 700,999 Bytes
- 7 Pages / 595.28 x 793.7 pts Page_size
- 83 Downloads / 187 Views
WORLD JOURNAL OF SURGICAL ONCOLOGY
CASE REPORT
Open Access
A popliteal giant synovial osteochondroma mimicking a parosteal osteosarcoma Andreas Toepfer*, Florian Pohlig, Heinrich Mühlhofer, Florian Lenze, Rüdiger von Eisenhart-Rothe and Ulrich Lenze
Abstract Both giant synovial osteochondroma and parosteal osteosarcoma are rare musculo-skeletal tumors, often localized in the vicinity of the knee. Misdiagnosis of a malignant bone tumor can entail fatal consequences. Etiology of giant synovial osteochondroma is widely unsolved but is believed to originate from synovial chondromatosis, a mostly benign metaplasia of the synovial membrane. Parosteal osteosarcoma is a low-grade surface osteosarcoma with a propensity of local recurrence and the potential of distant metastasis and therefore requiring a different therapeutical approach. We report the case of a popliteal giant osteochondroma mimicking a parosteal osteosarcoma. Relevant facts of this rare entity regarding pathogenesis, treatment, and differential diagnoses will be discussed. Keywords: Giant synovial osteochondroma, Chondromatosis, Bone tumor, Synovial metaplasia, Parosteal osteosarcoma
Background For benign lesions of the bone, no reliable data regarding incidence rates are available. A large amount of benign bone tumors remains undiscovered due to an asymptomatic course. Many diagnoses of benign bone lesions are incidental findings. Malignant primary bone tumors are even less frequent, accounting for only 0.2% of all neoplasms [1]. Classic, high-grade osteosarcoma is the most common primary malignant tumor of bone (35% of all bone sarcomas), parosteal osteosarcoma is far less frequent though, amounting to only 5% of all osteosarcomas. The second most common localization for parosteal osteosarcoma is the proximal tibia, after the distal metaphysis of the posterior femur. Most patients are young adults. A limitation of flexion of the affected knee due to a painless swelling may be the initial symptom. Complete excision is mandatory to avoid recurrence and progression to high-grade osteosarcoma [2]. Giant synovial osteochondroma is a very rare form of an osteochondromatous tumor and not to be confused with classic osteochondroma (osteo-cartilaginous exostosis), the most common bone tumor. Pathogenesis of this lesion is related to a synovial metaplasia in most * Correspondence: [email protected] Klinik für Orthopädie und Sportorthopädie, Klinikum rechts der Isar der Technischen Universität München, Ismaningerstr. 22, 81675 Munich, Germany
cases. Descriptions are limited to case studies although its vicinity to large joints and tendons implies a high rate of mechanical impairment. Predilection site is the intraarticular, infrapatellar region of the knee. Besides an intra-articular form, which is often named giant synovial osteochondroma, an equally rare extra-synovial form does exist. It preferentially appears in the tendonsheath-rich areas of hand and foot or the knee and is also referred to as extraskeletal chondroma. Differentiation between parosteal osteos
Data Loading...
