Sunday 1 January 2017

Spinal Epidural lesion MRI

Clinically lower limb weakness, left upper limb radiculopathy.
Here is MRI cervical spine with contrast
MRI Report

MR imaging of cervical spine with contrast reveals:
An ~ 20x9mm focal anterior epidural lobulated mixed signal intensity lesion on left side of cord at C6-7 causing moderate compression over cord, corresponding exiting C7 nerve root not seen separately in neural foramen. Lesion has central low signal stripe on T2w images and rest of the lesion is iso intense on T2 , iso to hyper intense signal on T1 w images, moderate to avid enhancement on post contrast.
DDs given were : Spinal epidural Hematoma, Neurofibiroma, Lymphoma.

Operative findings and Histopathology Report

Gross appearance: Specimen consist of dull gray brown tissue, dilated vein.
Microscopy: single collapsed undulating vascular channel devoid of any recognizable lining endothelia and smooth muscle component. Collapsed lumen show RBCs.
No e/o malignancy.

Final diagnosis : Venous Ectasia.

Spinal Epidural Venous Ectasia /Varix

Epidural Ectasia / Venous varix is an uncommon entity originally reported in the literature by Cohen in 1941. The incidence has been reported to be .07% to 1.3%.

The vertebral venous plexus consists of a retrovertebral plexus framed by paired anterior internal vertebral veins which are oriented craniocaudally and connected to the ascending  veins, these veins are located laterally on the vertebral bodies, via the supra- and infrapedicular veins. The plexus veins course close to the neural foramina and exiting nerve roots. The segmental veins connect the ascending lumbar veins to the inferior vena cava. This system of veins is valveless, thereby permitting retrograde flow and vascular dilation. The abnormal flow and dilation may occur in cases of caval compression, which may be seen with increased abdominal pressure.This has been postulated as an etiologic factor in the development of epidural varices.
Clinically, such varix in lumbar region, patients often present with radicular symptoms, such as pain, numbness, or parasthesias of the legs. An increase in intra-abdominal pressure with compression of the inferior vena cava and resulting venous engorgement and nerve root compression is suggested as cause. This scenario can be seen in pregnancy, obesity, and the valsalva maneuver.
such varix in cervical region is further rare and in our case this was causing cord compression.
Such venous dilation is also associated with a history of trauma and concurrent herniated disc. The hypothesis that the development of the varix may be secondary to compression of vertebral veins by the adjacent disc, thereby leading to dilation and thrombosis.
Imaging findings of this entity are often non-specific. On CT, the lesion appears as a soft-tissue density in the epidural space, often extending into the neural foramen. Myelography may disclose a filling defect in the contrast column at the disc space level. On MRI, the varix appears as a dilated with variable signal, T1 hypo intense to iso intense. May be T1 bright due to sub acute stage thrombus in the varix. Fine serpiginous flow void may be seen in the epidural space as in our case hypointense on T1- and T2-weighted images. The dilated vein will show enhancement following intravenous contrast administration.

As the appearance is non specific, the differential diagnosis may include epidural hematoma or abscess, herniated disc, or some times neurogenic tumor with neural foraminal component.
Treatment is surgery with coagulation and resection. Postoperatively, patients often report relief of symptoms. There are no any reports of recurrence of this entity following surgery.

We have presented a case of symptomatic epidural varix. This entity is extremely rare, and a radiologist will likely encounter only a handful of such cases in his or her career. However, the diagnosis should be suggested in the proper clinical setting when an epidural lesion brightens on T2 images and enhances with contrast.

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