Osteosarcoma can be felt by touch, and its main clinical manifestations include persistent progressive pain, which intensifies at night. Secondly, there are local lumps, commonly located at the distal femur, proximal tibia, and proximal humerus, which are high incidence areas for osteosarcoma. In such cases, you don't even need to touch it; you can see it with the naked eye because the swelling is quite severe. Additionally, the surrounding skin may appear reddened and warm, and superficial veins may become prominently swollen, indicating that the skin over the affected area looks different from normal skin. Moreover, in the area affected by osteosarcoma, the bone may show a spindle-shaped enlargement, looking like a spindle-shaped lump, causing the joint area and the surrounding normal joints to be clearly abnormal. Therefore, in cases of obvious symptoms of osteosarcoma, not only can you see the tumor, but you can also feel it. However, patients often will not let you touch it, as touching can cause pain and even force the joint and surrounding muscles into a forced state. This forced condition helps alleviate pain in the joint and surrounding areas. Thus, osteosarcoma can indeed be felt by touch.