Fibrous dysplasia of lumbar spine

Case contributed by Dr James Sheldon


Back pain

Patient Data

Age: 65 years
Gender: Female

Expansile, lucent lesion within the right transverse process and pedicle.

Within the right aspect of the L4 vertebral body is a well-defined low T1 and mixed low and high T2 signal lesion extending into the right transverse process, pedicle and lamina. Extension into the superior endplate also noted. This lesion is expansile with right L4/5 neural exit foramen narrowing, and demonstrates avid contrast enhancement. There is contact of the exiting right L4 nerve root at this level.

In the anterior aspect of this vertebral body there is a smaller, well-defined lesion with low T1 signal and relatively isointense T2 signal, which demonstrates contrast enhancement.

Minor L4/5 and L5/S1 disc bulge without spinal canal narrowing. The left L4/5 and bilateral L5/S1 neural exit foramen are capacious.

Vertebral height, disc height, alignment and bone marrow signal are otherwise normal.

The conus terminates at the L2 level and is normal in appearance.


Expansile, enhancing lesion at L4 consistent with known Fibrous Dysplasia.

The lesion narrows the L4/5 neural exit foramen with contact of the exiting right L4 nerve root at this level, which likely accounts for the patient's symptoms.

Case Discussion

Biopsy result:

The sections show a core biopsy composed of irregularly shaped trabeculae of partially mineralized woven bone. These are haphazardly arranged in a moderately hypercellular fibrous stroma. Stromal cells have regular nuclear features with no mitotic figures and no osteoid is identified. The features are suggestive of fibrous dysplasia.

No evidence of malignancy seen.

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Case information

rID: 33949
Published: 2nd Feb 2015
Last edited: 9th Dec 2020
Inclusion in quiz mode: Included

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