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Case Study: Intradural Extramedullary Lesion at L1

Case Study: Intradural Extramedullary Lesion at L1

The Problem

The patient was a 31-year-old-man who was referred to Dr. Virany Huynh Hillard in November 2020 after experiencing progressively increasing pain and weakness in his left leg. Prior to this visit, the patient had been seeing a chiropractor for conservative management.


The Diagnosis

The patient’s condition combined with the initial x-ray imaging report of the lumbosacral spine indicated scoliosis and mild degenerative disc disease. Further workup with MRI imaging illustrated a 1.7cm tumor at LI. Given the size, there is compression of the nerve root explaining the pain and weakness down the left leg. Dr. Virany Huynh Hillard met with her colleague Dr. Kaushik Das, a neurosurgeon specializing in spine disorders, and together determined that the patient would benefit from a T12-L1 laminectomy for resection of the tumor and recommended surgery. After risks, benefits, and alternatives were explained, the patient understood and wished to proceed as soon as possible.


The Treatment

L1 tumor compressing nerve root.

In order to alleviate pain, restore strength to the left leg, and remove the L1 lesion, Drs. Virany Huynh Hillard and Das worked as a team to perform a T12-L1 laminectomy for resection of intradural extramedullary lesion with the use of an intraoperative microscope. After the incision was made to identify the spinous process of T12-L1, the dissection was carried laterally to expose the lamina and the medial facet of T12 and L1 and a laminectomy of T12 and L1 was performed.


The surgeons could then identify the presence of the tumor right in the center of their T12-L1 laminectomy. Coming from a sensory rootlet, they identified the top and bottom of the soft friable mass. After first taking a portion of the lesion to be sent off for frozen section, Drs. Virany Huynh Hillard and Das were able to debulk and fold the tumor for an easier removal.


Neuro stimulation was then used to identify the anterior motor nerve roots at T12-L1 and the rootlet was stimulated indicating that it was sensory in nature since motor function was not revitalized. The surgeons then removed the tumor in multiple small fragments until it was down to the attachment of the rootlets. Since this was a sensory nerve, Drs. Virany Huynh Hillard and Das used bipolar cautery, coagulated the attachment to the tumor and resected using microscissors. To tease out any other remaining pieces of the tumor on the sensory rootlet, microdissection was used. After the tumor resection, motor evoked potential response was normal and the surgeons irrigated the area to make sure there was no bleeding. Once they were satisfied with hemostasis Drs. Virany Huynh Hillard and Das proceeded to close in a multilayer fashion.



The Outcome

After living with progressively increasing pain and weakness in his left leg, four months after surgery the patient is doing very well.


He is in physical therapy, his wound has completely healed, his extremity strength has improved dramatically with only a little bit of numbness in that L1-L2 distribution and his foot. A follow up imaging study will be done at six months post operation.


1.7cm tumor at L1.

Post-op MRI showing no tumor.




Meet the Surgeons

Dr. Virany Huynh Hillard received her B.A. in Biological Sciences from Harvard University in 1995 and her M.D. cum laude from New York University in New York, NY in 1999. She completed an internship in general surgery at the New York Medical College Westchester Medical Center in 2000 followed by a neurosurgery residency at the same institution from 2000-2005 under the chairmanship of Drs. William Couldwell and Raj Murali. From 2002-2003 Dr. Virany Huynh Hillard served as a research fellow under Richard Zeman, Ph.D. and Joseph Etlinger, Ph.D. in the Spinal Cord Injury Laboratory, Department of Cell Biology and Anatomy at New York Medical College. She received the prestigious Synthes Award for Research on Spinal Cord and Spinal Column Injury in 2004. Click here to learn more about Dr. Virany Huynh Hillard.




Kaushik Das, MD

Dr. Kaushik Das is a neurosurgeon specializing in spine disorders. Dr. Das has been alleviating patient fears for more than a quarter of a century. He went into neurosurgery because he wanted to make an impact. Dr. Das began his journey in 1989 at the State University of New York at Stony Brook where he completed his undergraduate degree in biochemistry. He went on to attend medical school at the State University of New York in Brooklyn (Downstate) where he graduated cum laude in 1993 and was a member of AOA honor society. He completed his Neurosurgery residency in 1999 from NY Medical College/ Westchester Medical Center in Valhalla NY and then went on to complete a Spine Fellowship at the Barrow Neurologic Institute in Phoenix, AZ in July 2000. He currently is a Clinical Associate Professor of Neurosurgery at NY Medical College. Click here to learn more about Dr. Das.