A 25-year-old man has a four-month history of severe thigh and knee pain. He
has pain both at rest and at night. He has tenderness on palpation of the thigh.
He has been febrile and has an elevated white blood cell count. The AP and LAT
radiographs of the femur are shown in Slide 1. The
high and lower power histologic sections are shown in Slides
2 and 3.

Slide 1

Slide
2

Slide 3
The most likely diagnosis is:
- Osteogenic sarcoma
- Osteomyelitis
- Malignant fibrous histiocytoma
- Fibrosarcoma
- Ewing sarcoma
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