NBME 18 Answers ↦
Looking back, I know it's osteosarcoma but the lung metastases made me think of Ewing's
Ewing sarcoma is common in boys <15 years old. This patient is a 70 year old woman. The stem notes elevated periosteum and a sunburst pattern which are characteristic of osteosarcoma.
Also "sunburst pattern" is a classic description of Osteosarcoma.
I think that's a chondrosarcoma (tumor of malignant chondrocytes, found in the pelvis, proximal femur and humerus, FA 2020 pg. 465)
also known as “bimodal” (since distribution shows two modes: in the second decade of life and the eighth)