ALT Woven bone with prominent osteoblastic rimming surrounded by spindle-shaped cells @IARCWHO

ALT Axial CT showing the tumor is confined to the cortex without medullary involvement @IARCWHO

ALT A 45-year-old female presents with severe muscle weakness, bone pain, and multiple fractures. Laboratory tests reveal profound hypophosphatemia. Spindle cell tumor with focal grungy calcification @IARCWHO

ALT A 50-year-old male presents with persistent aching pain in his heel bone. Well-circumscribed oval radiolucency with calcifications @IARCWHO

ALT An 11-year-old female presents with an expansile tibial lesion showing multiple fluid-fluid levels on MRI. Cyst wall showing lack of distinctive cell lining and composed of spindle cells with scattered giant cells and hemorrhage @IARCWHO

ALT A 22-year-old male presents with chronic pain in his proximal tibia. Imaging shows an eccentric, metaphyseal, lobulated lytic lesion with a sclerotic margin. Stellate cells embedded in a myxoid matrix are seen on the right with more cellular areas containing round cells on the left @IARCWHO

ALT Lateral radiograph showing a lytic lesion in the distal femoral epiphysis @IARCWHO

ALT Sheets of chondroblastic oval to polygonal cells and osteoclast-like giant cells @IARCWHO

ALT A 30-year-old male presents with a slow-growing, painful mass in his lower leg. Imaging reveals a soap bubble osteolytic lesion in the anterior tibial cortex. Neoplastic epithelial cells forming tubular structures @IARCWHO