PMC3504234_01
Mass observed in the infrapatellar region.
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fig1
Upon admission the mass could be easily seen on the right knee right below the patella in the infrapatellar region (Figure 1).
Osseous structure in the infrapatellar fat pad.
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fig2
A standard X-ray examination revealed osseous structure in the infrapatellar site (Figure 2).
Computed tomography showing the mass with its osseous content in the infrapatellar region.
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fig3
According to the CT (Figure 3) and MRI (Figures 4(a) and 4(b)), a differential diagnosis between synovial osteochondromatosis, synovial sarcoma, and para-articular chondroma should be carried out.
(a) Axial T1-weighted image. (b) Axial T2-weighted image showing clearly the mass in Hoffa's fat pad underlying the patellar tendon and extra-articular.
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fig4
According to the CT (Figure 3) and MRI (Figures 4(a) and 4(b)), a differential diagnosis between synovial osteochondromatosis, synovial sarcoma, and para-articular chondroma should be carried out.
Intraoperative image showing the mass before its final excision.
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fig5
The patient was then operated and a mass of 6 cm approximately in diameter was excised under general anaesthesia along with its pedicle base (Figures 5 and 6).
A lipomatous mass of 6 cm in diameter.
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fig6
The patient was then operated and a mass of 6 cm approximately in diameter was excised under general anaesthesia along with its pedicle base (Figures 5 and 6).
Area of osseous metaplasia.
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fig7
The result of this histological examination suggested a fibrolipoma with osseous and cartilagenous metaplasia (Figures 7 and 8).
Area of cartilagenous metaplasia.
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fig8
The result of this histological examination suggested a fibrolipoma with osseous and cartilagenous metaplasia (Figures 7 and 8).