Grade III. A 74-year-old man. A barely visible osteolytic bone tumor is observed in the diaphysis of the left tibia (solid arrow); margins are poorly defined. There is permeative tumor growth in the adjacent lateral cortex (dashed arrow). This latter point prompts the assignment of Lodwick growth grade III, irrespective of any descriptor of the adjacent lucency. The tumor proved to be a metastasis from a caecal carcinoma