Osteosarcoma knee LSBU

Description: ACR-code 451-3221 14 year old girl with pain and swelling above the right knee.
The skeleton is immature. There is expansion and increased density of the distal end of the right femur. The centre of radius of the tumour is in the distal femoral metaphysis. There is a soft tissue mass expanding outside the bone. The elevation of periosteum is marked with strands of newbone, extending into the tumour above the normal boundaries of the bone. There is a visible lamellar periosteal reaction over the proximal section of the metaphysis. In one view, it is impossible to separate endosteal newbone from overlying newbone. There is relative osteoporosis of the peripheral sections of the femoral metaphysis, which appearance does not completely exclude some patchy bone destruction. The visible line of bone cortex is interrupted on the medial side of the distal femoral metaphysis, implying some bone destrauction.