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Solitary fibrous tumor in thoracic spinal canal – a rare entity 2007

General Spine

Ajay Malhotra, MD

Scientific Poster

Exhibit Panels: 1

Purpose

To describe the MR imaging findings of a solitary fibrous tumor in the thoracic spinal canal. Solitary fibrous tumor is a rare spindle cell tumor deriving from mesenchymal cells that arises most commonly in the pleura. Extraserosal sites of origin have been reported, including meninges and CNS parenchyma. Rarely, solitary fibrous tumors may occur in the spinal canal as intradural extramedullary masses. We will discuss the imaging appearances of this rare entity with pathological correlation. Differential diagnosis of intradural extramedullary masses will also be discussed.

Methods & Materials

A 43-year-old gentleman presented with a two month history of non specific back pain, thoracic numbness and right leg weakness.Neurological examination showed loss of strength and coordination in the right leg. MRI of thoracic and lumber spine was requested due to clinical concern for cord compression.

Results

A 43-year-old gentleman presented with a two month history of non specific back pain, thoracic numbness and right leg weakness.Neurological examination showed loss of strength and coordination in the right leg. MRI of thoracic and lumber spine was requested due to clinical concern for cord compression.

MR imaging revealed a well-circumscribed intradural, extramedullary lesion measuring approximately 2 cm in size at the T4 level in the spinal canal posteriorly. The lesion was isointense on T1-W images and low signal on T2 WI. Intense, homogeneous enhancement was seen on post contrast images. The spinal cord at this level was pushed anteriorly.
The patient underwent surgical resection of this ovoid lesion. The tumor was found to be freely mobile, attached to a posterior nerve root. Gross total resection of the tumor was performed.
Histologically, the tumor predominantly consisted of spindle cells separated by abundant collagen matrix fibers. The tumor cells were strongly positive for CD 34 and vimentin, while negative for S-100 or SMA.

Conclusion

Solitary fibrous tumors are rare benign tumors that can uncommonly arise in spinal nerve roots. These must be differentiated from other intradural, extramedullary lesions like meningioma, schwannoma and hemangiopericytoma. Confirmation of diagnosis depends on immunohistochemical results.
This rare tumos should be included in the differential diagnosis of spindle cell lesions arising in the spinal canal.

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