Fibrous dysplasia - thoracic spine

Case contributed by Dr Mostafa El-Feky


Complaining of fibrous dysplasia for 30 years. Currently presented with right sciatica and foot drop.

Patient Data

Age: 40 years
Gender: Male

An expansile lytic lesion is noted involving T6 and T7 vertebrae contagiously with loss of vertebral architecture and vertebral body expansion with thin expanded bony cortical outline showing multiple defects secondary to expansion. The expansion is affecting the entire vertebral components, more involving the right side of the vertebral bodies and right transverse processes with more bulge towards the right side encroaching upon the dorsal spinal canal and related right sided dorsal nerves, notably at T6/7 level bilaterally, with marked compression upon the right T6/7 exiting nerve root. The overall formed mass lesion is measuring 7.8 x 7.5 x 6.2 cm in AP, SS and CC dimensions respectively. Related focal kyphotic deformity is noted with apex at T6/7 level. No associated scoliosis. These effects are accentuated by the involvement and expansion of the spinous processes of the involved vertebrae with mass effect along the related dorsal spinal cord at the same levels posteriorly. It is also extending to the right side of the related posterior mediastinum compressing the azygos vein. No other dorsal spine affection noted.

Rib involvement:

  • The lateral aspect of the left 6th rib body.
  • The bodies of the right 6th, 7th and 8th ribs with rib expansion exerting secondary diminished volume of the right lung lobe.  Fusion of the 6th and 7th vertebrae is noted with missing the proximal parts of their bodies; given history of previous surgical intervention.

Replaced matrix of T6 and T7 vertebrae showing T1 isointense signals with areas of hyperintensity, T2WI hyperintensity with loculations showing fluid levels reflecting hemorrhagic components. The lesion has a paravertebral component, larger on the right side. It extends also to the spinal canal forming an extra-dural component markedly compressing the spinal cord at the same level.

Case Discussion

Features of polyostotic expansile benign bone disease; known polyostotic fibrous dysplasia with the above-described involvement and mass effect of the thoracic spine involvement and secondary aneurysmal bone cyst change of the thoracic spine lesion. Fibrous dysplasia occurs rarely in the spine, especially in the thoracic spine. Fibrous dysplasia of the spine usually occurs as a part of the polyostotic form of the disease. See rID: 42871 for craniofacial manifestations in this patient.

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Case information

rID: 64500
Published: 3rd Dec 2018
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included
Institution: Dar El Ashaa Center

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