Abstract
Osteochondromas (OCs) are developmental anomalies that originate from the periosteum and typically form during enchondral ossification near the joints. Retro-patellar OC caused by exostosis forms in various intracapsular, intra-tendon, and joint-adjacent positions within the knee joint. In this case, a 19-year-old male presented with swelling and a mass in his left knee, which raised suspicion of bone tumors. After evaluating x-ray images and conducting histopathological examinations, the diagnosis was confirmed as retro-patellar OC.