Osteochondroma - spine

Case contributed by Assoc Prof Frank Gaillard


Weakness. Prior surgery as a child. Dx unknown at that time.

Patient Data

Age: 60 years

Evidence of prior surgery with laminectomy. Within the canal, displacing the cord, and compressing it, is a mass with intense high T2 signal, central low signal on all sequences, and thin peripheral enhancement. 

Differential for a mass with this signal characteristic includes chondroid containing lesions (chondrosarcoma, osteochondroma) and chordoma. A cystic mass with dystrophic calcification (e.g. neurogenic tumor) is another possibility although appearances would be most unusual. 


C7/T1 laminectomy is present. The T1-T3 facet joints are ankylosed bilaterally.

A calcified lesion is centered at the left C6/C7 vertebral canal continuous superiorly with the C6 right inferior facet. 

Conclusion: Combination of chondroid signal on CT and central ossification continuous with the adjacent bone is in keeping with an osteochondroma.

Case Discussion

The patient went on to have surgery. The tumor was found to be partially extradural, but with an intradural component protruding through a large dural defect which was repaired with dural substitute.


MICROSCOPIC DESCRIPTION: The sections show a chondroid lesion. It is mildly cellular, containing lobules of cartilage. The stroma is prominently myxomatous. Some of the matrix is mineralized. Occasional chondrocytes show mild nuclear enlargement and hyperchromasia. Binucleated forms are inconspicuous. There are no mitoses or necrosis. Some of the cartilage are surrounded by host bone. No invasion through the bone or soft tissue is seen.

There are no histological features to suggest a sarcoma. The lesional cells are S-100 and M2A positive. They are CAM5.2 negative, excluding a chordoma. The features are those of chondroma.

FINAL DIAGNOSIS: Osteochondroma

PlayAdd to Share

Case information

rID: 46057
Published: 23rd Jun 2016
Last edited: 7th Dec 2020
Inclusion in quiz mode: Included

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.