Patient: There is soreness and a clicking sound with joint extension. On recent radiographic findings, a wide basal bone protrusion with thick white calcification is seen on the medial side of the upper right tibia. What is the disease? Doctor: From your description, it looks like an osteochondroma. The single lesion is sometimes found by chance, which means that the symptoms you describe are most likely not caused by it, but mostly by the knee joint itself. Therefore, we recommend that you visit a bone tumor specialist to clarify the diagnosis and to exclude the possibility of multiple occurrences. If the disease and condition are consistent with what I mentioned, some asymptomatic patients do not need surgery because it is a benign lesion, and regular review can be done.