Shape size and consistency
On palpation, osteomas feel hard (hence the name ivory sarcoma), with a smooth flattened mound surface. Chondromas also have a flat surface and have a hard or solid consistency. Enchondromas cause a fusiform mass on the surface of the bone, while ecchondroma forms a sessile mass. Superficial metastatic tumors present as swelling with an irregular surface, and on palpation, the swelling may feel more or less hard, sometimes even cystic, compressible, and pulsatile.
Osteosarcoma has a smooth surface, except when it spreads to the surrounding tissue when it becomes irregular. On palpation, it feels firm or rather soft. Osteosarcoma and osteoclastoma cause asymmetrical swelling, while Ewing’s sarcoma causes symmetrical fusiform swelling of the bone. Ewing’s sarcoma’s surface is smooth with indistinct ends and with firm and rubbery consistency. Osteoclastoma has a smooth surface, and the consistency is bony hard; the tumor may crackle and bend if touched and feels like a broken eggshell if the bone overlying the tumor is very thin.