Peripheral nerve sheath tumor of S1 nerve root

Case contributed by Dr Ammar Haouimi


Left sciatica.

Patient Data

Age: 40 years
Gender: Female

The MRI sequences demonstrate a well-defined ovoid mass 25 x 23 x 20 mm, centered on the left first sacral foramen which is enlarged. It elicits a low signal on T1, low signal centrally with hyperintense rim peripherally on T2 "target sign". The postcontrast sequences show homogeneous enhancement.

Case Discussion

MRI features of a well-defined mass enlarging the first left sacral foramen with "target sign" on T2 and homogeneous enhancement, suggestive of a peripheral nerve sheath tumor of S1 nerve root.

The "target sign" is highly suggestive of neurofibroma. It is thought to be due to the presence of collagenous stroma in the central area.  Occasionally also can be seen in schwannomas and malignant peripheral nerve sheath tumors.

PlayAdd to Share

Case information

rID: 88223
Published: 30th Mar 2021
Last edited: 30th Mar 2021
System: Spine
Inclusion in quiz mode: Included
Institution: Aurès Medical Imaging Center - Batna Algeria

Updating… Please wait.

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

 Thank you for updating your details.