INTRAMEDULLARY TUMOR OVERVIEW

General Comments

Hemangioblastomas are less common and sometimes occur in conjunction with Von Hippel Lindau Disease (a disease in which patients are prone to developing cysts in the kidney and other organs). These Intramedullary Tumors occur most often in the Cervical Spinal Cord and are often quite indolent.

Lipomas (Fat Cell Tumors) are unusual benign tumors. There are a couple of varieties that occur as Intramedullary Spinal Cord lesions. (For a thorough review please consider consulting the comprehensive article Spinal Lipomas by Jeffrey P. Blount, M.D., and Scott Elton, M.D.)

A. Lipoma of the Terminal Filum is a truly occult lesion; therefore the true incidence of "fatty filum" is unknown. In modern times, more of these "lesions" are incidentally identified by virtue of the fact that MRI Scans are done to investigate other conditions. According to authors Blount & Elton, Lipomas limited to the Filum Terminale "represented 13 to 26% of lesions accounting for tethered cord." The "Tight Filum Syndrome" is one of the causes of a "Tethered Spinal Cord". In these cases an abnormally enlarged Filum Terminale prevents the normal ascent of the Spinal Cord within the Lumbar Spinal Canal during normal development. (See Figures 2A & 2B) The medical literature on this subject claims that "greater than 90% of cases in which this diagnosis is made demonstrate adipose (fat) cells in the Filum Terminale".

B. Lipomyelomeningocele (Lipoma of the Conus Medullaris) is the most common "fatty mass" occurring along or within the Spine. Lipomyelomeningocele is a form of Occult Spinal Dysraphism in which a subcutaneous fibro-fatty mass extends through the fascia in the Thoraco-lumbar region to cause a "defect" in the Spinal Lamina to displace the Dura as it infiltrates and "tethers" the Spinal Cord.

Lipomas of the Conus Medullaris occur in 1 in 4000 births in the United States with females being affected slightly more often than males.

The diagnosis of Lipomyelomeningocele is usually made early in childhood when a peculiar skin lesion or fatty mass is observed. IT IS IMPORTANT FOR PEDIATRICIANS, NURSE PRACTITIONERS AND GENERAL PHYSICIANS TO RECOGNIZE THAT THE PRESENCE OF A "SKIN MARKER" OVERLYING A CHILD'S SPINE MAY INDICATE AN UNDERLYING SPINAL DYSRAPHIC CONDITION. Unfortunately this problem may not be made until adulthood when back pain or a progressive neurological deficit calls attention to the problem.

SYMPTOMS

PAIN is the most common presenting symptom of Intramedullary Spinal Cord Tumors in adults. The pain typically localizes to the level of the Tumor. Sensory (numbness and/or tingling) or motor (weakness and spasticity) complaints are the initial symptoms in up to one third of patients. Upper extremity symptoms predominate in cases of Cervical Tumors. One sided (or asymmetrical) involvement is common. Thoracic Spinal Cord Tumors produce spasticity and sensory changes. Numbness is a common complaint and usually begins in the more peripheral locations of the lower extremities. Tumors of the Lumbar region and Conus Medullaris present with back and leg pain. Bladder and bowel dysfunction tends to occur early.

DIAGNOSIS

Figure 1: MRI Scan (Sagittal View-Gadolinium enhanced) Extensive Cervical Spinal Cord "Mixed Glioma" with Syrinx in the Medulla The Syrinx (Left-curved Arrow) at the Cervico-medullary Junction causes considerable displacement and compression of the surrounding Neural Structures. The Tumor (Horizontal Arrow) extensively infiltrates the Spinal Cord.

TREATMENT

Surgery

Some "localized" tumors may be accessible using Minimally Invasive Microsurgical Techniques.

A. Intramedullary Tumors That CAN Be Totally Removed.

In cases of benign tumor, our strong preference favors Minimally Invasive Microsurgical Gross Total Removal particularly if a clear demarcation/interface exists between the Tumor and the Spinal Cord. Surgical removal alone provides long-term tumor control or cure for Hemangioblastomas, almost all Ependymomas, Filum Terminale Lipomas and some well-circumscribed Astrocytomas.

Figure 2A (Left): Post-myelographic CT Scan (Axial View) L5 Level Tethered Spinal Cord with Filum Terminale Lipoma, Bifid Spine (Horizontal Bi-directional Arrow) in a 38 year old male with Urinary incontinence and Leg Pain. At this level of the Spinal Canal one would not find Intradural Nerve Roots of the diameter represented by the images demonstrated here (Oblique Arrows).(See Figures 3 & 4 for Operative Photos) Figure 2B (Right): Post-myelographic CT Scan (Axial View-Same Patient) Tethered Spinal Cord with Filum Terminale Lipoma and Bifid Spine. The point of "Tethering" is indicated by the centrally located posterior intradural structure (Vertical Arrow.) The posterior Spinous Process and Lamina are also malformed (Right-angled Arrow.)

Figure 3: Operative Photo (Same Patient). L4, L5 and Sacral Laminectomies were performed to gain access to the Filum Terminale Lipoma with Tethered Spinal Cord Syndrome. In this photo the Dura has been opened, the Lipoma has been transected and the Tether has been relieved (Vertical Arrow indicates the Distal portion of the Lipoma.) The Filum Terminale is markedly expanded by the Lipoma (Down-curved Arrow.)

Figure 4: Operative Photo (Same Patient.) The Distal portion of the Lipoma (Left Curved Arrow) has been resected and the Tethering of the Spinal Cord has been relieved. The Sacral Nerve Roots (Left Sided) are seen in the Extra-dural Space (Horizontal Arrows) after extensive Decompressive Foramenotomies were performed. The Intra-dural segment of the Sacral Nerve Root is seen exiting the Dura (Vertical Arrow) and can be followed to its Extra-dural component.

B. Intramedullary Tumors That CANNOT Be Totally Resected.

Some Glial Tumors that cannot be totally resected or are recognized to be more aggressive (Anaplastic Astrocytoma/Glioblastoma, etc.) will require Post-operative Radiation Therapy and possibly Chemotherapy as well.

Lipomyelomeningoceles cannot usually be resected due to the fact that functional neural tissue is intimately interlaced with the Lipoma. The only supportable indication for surgery in these patients is Neurological Symptoms relating to demonstrable Tethering of the Spinal Cord.

Radiation Therapy

Stereotactic Radiosurgery

Chemotherapy

Rehabilitation

PROGNOSIS

The current treatment of Spinal Cord High-grade Astrocytomas, which includes surgical debulking, Radiation Therapy and Chemotherapy, is usually inadequate.

For the less aggressive Tumors, long-term survival is common although Neurological deficits consequent to the Tumor's effect can be quite severe and disabling.

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This page last edited on 2/19