Chondrosarcoma Background: Most common bone cancer in adults (40%) Most frequent sites of origin: Pelvis and proximal femur Characterized by malignant cartilage matrix production without osteoid Bony destruction + calcification Very chemoresistant Subtypes: Conventional (90%) Non-conventional (10%) Clear cell Dedifferentiated Mesenchymal Myxoid Juxtacortical Treatment: If resectable: Surgery  If metastatic/not resectable: systemic therapy Ivosidenib (If IDH1 mutation) Pazopan