A popliteal giant synovial osteochondroma mimicking a parosteal osteosarcoma.
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.
Klinik für Orthopädie und Sportorthopädie, Klinikum rechts der Isar der Technischen Universität München, Ismaningerstr, 22, 81675 Munich, Germany. toepfer@tum.de.
Andreas
A
Toepfer
Florian
F
Pohlig
Heinrich
H
Mühlhofer
Florian
F
Lenze
Rüdiger
R
von Eisenhart-Rothe
Ulrich
U
Lenze
D000328:Adult; D001859:Bone Neoplasms / Q000175:diagnosis* / Q000601:surgery; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D015831:Osteochondroma / Q000175:diagnosis* / Q000601:surgery; D012516:Osteosarcoma / Q000175:diagnosis* / Q000601:surgery; D011151:Popliteal Cyst / Q000473:pathology* / Q000601:surgery; D011379:Prognosis; D000074402:Synovectomy; D013583:Synovial Membrane / Q000473:pathology*