1. Chondroblastoma

2. Synonyms and related keywords:
Codman tumor,
Cartilage-containing giant cell tumor, calcified giant cell
tumor, epiphyseal chondromatous giant cell tumor,
Epiphyseal tumors,
Benign cartilaginous neoplasms, chondroclasts

3. Rare benign tumor.
Epiphysis.
CODMAN’S TUMOR – first described by Codman 1931.
<1% of all primary bone tumors.
Develops from – Cartilage germ cells.
Reticulohistiocytes – according to Valls.

4. Age:
Active epiphysial plate growth
Range: 3-73 yrs.
Teenagers – before obliteration of growth plates.
90% in 5 – 25 yrs. of age.
Sex
Male : Female 2 : 1

5. Site:
EPIPHYSIAL region of long bones and occasionally to adjacent
metaphysis.
Common occurrence:
Lower extremity (72% of cases), in which 50% of the
chondroblastomas occur around the knee.
Prox. Humerus 18% > Prox. Tibia 17% > Distal femur 16%
> Prox. Femur 16% > Ankle bones 9%
Size: 1- 6 cm.

6. Clinical features:
Non-specific and vague.
Pain & swelling – several months.
May be referred to nearest joint
Some loss of joint function & muscle wasting.
Joint effusion esp. around knee.
Pathological fractures – rare.

7. Mortality/Morbidity:
Without surgical excision, the tumor may extend
into the adjacent soft tissues or synovium and
metastasize to distant organs.
Metastasis, when it occurs,
most frequently involves the lungs and
tends to occur at the time of primary tumor recurrence.
Widespread metastases and death have been reported.

8. Radiological features:
X – RAYS:
Lytic area –
Oval or round
< ½ of epiphysial area.
Thin rim of sclerosis
Punctate or streaky
calcification.

9. Usually open growth plates.
In metaphysial extension,
crossing growth plate results
in – Eccentric location &
bulging expansion of cortex.

10. C. T. Scan:
Shows clearer exact evaluation and extent.

11. M.R.I. Scan:
Better extent of involvement.

12. 16 yr old girl
Pathological # - rare

13. 14-year-old boy.
Well-circumscribed, thin,
sclerotic margins.
 Chondroblastomas may have
sclerotic, nonsclerotic, or
incompletely sclerotic borders.

14. MRI T1 image

15. MRI T2 image
The lesion is confined to the
epiphysis.
The presence of surrounding
edema is best depicted with
MRI.

16. Pedicle and transverse
process of a lumbar
vertebra.
Diagnosis of
chondroblastoma was
confirmed at pathologic
examination

17. Chondroblastoma rarely occurs
in spine.

18. 17-year-old boy.
A subtle, solid, adjacent
metaphyseal periosteal reaction is
present medially.
A metaphyseal periosteal reaction
occurs in 15-30% of
chondroblastomas.

19. Fluid-fluid levels are
occasionally seen on images of
chondroblastomas,
Can simulate aneurysmal bone
cysts.

20. Uptake of the bone-seeking
agent may be due to –
regional hyperemia of the
tumor.

21. Pathology:
Gross:
Usually well demarcated lesions.
Capsule – thin, easily disruptable
Soft, reddish –purple, friable, focally fritty tissue.
Cystic spaces and haemorrhages may be seen.

22. Microscopic:
Islands of chondroblasts within
uniform polyhedral closely
packed cells.
Background of fibrous stroma
cells within the islands –
PAVING STONE
APPEARANCE.

23. Cells – round, plump and active.
Pericellular lattice-like fine calcification – “CHICKEN WIRE” or
“PICKET FENCE” pattern.
Small granular purplish areas of micro calcification.
Multinucleated Giant cells – scattered in stroma.
Often prominent, dilated blood vessels at centre & periphery.

24. Differential diagnosis:
Enchondroma
Hand, diaphysial.
G.C.T.
Eccentrical, soap bubble or trabecular pattern
No calcifications
Often after closure of growth plate.
Central chondrosarcoma
Slow growth, severe pain & margins not demarcated.

25. Chondromyxoid fibroma
Metadiaphysis (Characteristic).
Septate.
Monostotic fibrous dysplasia.
Ground glass appearance.
No calcifications.

26. Treatment & prognosis:
Curettage and autologous bone grafting – high recurrence rate
(10 – 35%).
Close follow up & observation till skeletal maturity – when
potential growth remaining & lesion abuts epiphysial plate.
Marginal extra capsular excision – when growth plate not
at all at risk, low recurrence rate.
Defect – Autologous bone grft.

27. Methacrylate adjunct – when excision impractical &
intra capsular curettage is of high risk of recurrence due to
surgical inaccessibility.
Curettage followed by cryosurgery:
In case of recurrence or when associated with ABC.
Yields consistent good results with a high cure rate when entire
tumor is adequately frozen by liquid nitrogen.

28. Radiosensitivity:
Radiosensitive tumor
Not used for uncomplicated cases – potential hazards of
irradiation induced malignant transformation.
Even more favorable results with other modes.