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