Incidental Bone Lesions | |||||||
Localization | n | Age Range (Mean) | Maximum diameter Range (Mean) | Cortical contact (n) Scalloping | Management | Follow-up Range (Mean) | |
Enchondroma long bones n = 63, for illustration see Figures 1-3 | |||||||
Humerus proximal | 18 | 38 - 77 y (53y) | 1.0 - 8.0 cm (4.5 cm) | Scalloping <1/3 in 2, >2/3 in 2 no change during 3 y f/u Other patients no scalloping | 1 biopsied at arthroscopy 1 curetted to exclude sarcoma; Histology on both “enchondroma” | Imaging for 12 patients available at 1 - 7 y (3.69 y) no change Clinically asymptomatic 4 additional patients at 4, 9, 10, 12 y | |
Humerus diaphysis | 2 | 42 - 53 y | 1.5/9.0 cm | No scalloping |
| 1 patient asymptomatic at 12 y | |
Femur distal | 27 | 34 - 72 y (50.8 y) | 0.8 - 11.0 cm (3.5 cm) | Only the patient with the 11 cm long enchondroma had minimal scalloping remaining unchanged at 7 y f/u | 2 cases curetted and filled with graft to prepare for cruciate ligament reconstruction/knee replacement Histology: enchondroma | Imaging for 9 patients available at 1 - 7 y (3.4 y) no change 8 additional patients asymptomatic at 2 - 10 y (5.6 y) | |
Femur mid-diaphysis | 4 | 18 - 34 y (26.5 y) | 2.7 - 4.6 cm (3.3 cm) | No scalloping |
| 1 patient followed from age 18 y to age 20 y showed increase in diameter from 3.2 to 4.6 cm without scalloping—to be followed | |
Femur proximal | 2 | 62/51 y | 7.0/2.3 cm | No cortical contact |
| Imaging for 1 patient at 2 y—no change | |
Tibia proximal | 4 | 22 - 55 y (45 y) | 2.1 - 6.8 cm (4.0 cm) | 1 mild scalloping eccentric lesion unchanged over 4 y f/u |
| Imaging available for 3 patients at 3, 4, 8 y—No change | |
Tibia distal | 1 | 53 y | 3.0 cm | Eccentric with extracortical extrusion | Biopsy: benign enchondroma | No f/u | |