Early-Onset Bevacizumab-Associated Knee Osteonecrosis in a Young Adult With Astrocytoma

We describe a rare case of knee osteonecrosis in a 22-year-old man with astrocytoma and neurofibromatosis type 1 after short-term treatment with bevacizumab and corticosteroids. Magnetic resonance imaging (MRI) identified infarctions and osteonecrosis of the distal femur and proximal tibia. Osteonecrosis associated with bevacizumab is typically limited to the jaw; this case highlights the potential for earlier, extra-jaw involvement. Clinicians should maintain a high index of suspicion for osteonecrosis in patients on vascular endothelial growth factor inhibitors, especially with concurrent steroid use, and consider prompt MRI in the evaluation of unexplained joint pain.