Fig. 1

Case 1. A 60-year-old man with intramedullary osteosclerosis of the right femur. Preoperative radiography shows massive sclerotic intramedullary lesion of the right femoral shaft and cortical bone thickening (white arrow). Left panel is an anteroposterior view. Right panel is lateral view (a). Preoperative CT (axial) shows medullary cavity narrowing (white arrowhead) (b). Preoperative MRI of T1-weighted SE sequence was hypointense, corresponding to the intramedullary sclerosis visualized on radiograph and CT (whiteline arrow) (c), and T2-weighted STIR sequence showed high signal intensity in the medullary cavity and without soft tissue mass (whiteline arrowhead) (d). Whole-body 99mTc-MDP bone scan showed abnormal tracer uptake in the right femur (black arrowhead) (e). Postoperative radiography. Gray arrow indicates the biopsy hole (f). Hematoxylin-eosin staining of the specimen from an open biopsy showed trabecular bone sclerosis with hypocellular fibrous tissue. Scale bar indicates 100 μm (g). Radiography at 39 months postoperatively. The bone hole was completely repaired (gray arrowhead) (h)