My knee won’t stop swelling! Osteosarcoma

Case presentation

A 6-year-old female presents with persistent, worsening right knee swelling for the past 2 months. The area has become painful over the past few weeks, especially at night. There has been no fever, erythema, or swelling of the other extremities or joints. There is no report of trauma, but prior to the development of symptoms, the child was quite physically active and it is possible that she may have injured the knee while playing. The child’s physical examination is remarkable for generalized swelling of the right knee. She has minimal pain to palpation of the superior aspect of the knee; full extension of the knee produces pain. There is no warmth, erythema, or fluctuance.

Imaging considerations