martedì 22 settembre 2009
Figure 1: Intramedullary mass at the T9-T10 level with hyperintense signal on T1-weighted sequence.
Figure 2: Intramedullary mass at the T9-T10 level with hyperintense signal on the T2 -weighted sequence.
Figure 3: Fat suppression on the STIR image.
Figure 4 and Figure 5: Fat saturation on the T1 fat saturated post contrast images and no enhancement of the lesion. There also is splaying of the spinal cord at this level.
Diagnosis: Intramedullary lipoma (surgically proven)
99% of intramedullary lipomas are associated with spinal dysraphism. Most tumors occur in the dorsal cervical and thoracic cord.
Intramedullary lipomas are rare. These comprise 1-2 % of intramedullary tumors. Multiple noncontiguous intramedullary lipomas are even rarer. These affect both sexes equally. Most patients present with symptoms during the first 2 -3 decades of life. Most have a slow progression of neurological deterioration. Sensory disturbances, pain, ataxia and lower extremity weakness are the most common presenting complaints. Urinary and bowel incontinence present later. CT can show a fatty lesion and MRI is diagnostic. They have a short T1 relaxation time and are bright on T1 weighted images and also bright on T2 weighted images following signal intensity of subcutaneous fat. There is very little enhancement. Treatment is still controversial and some physicians advocate early decompression before onset of symptoms because of significant residual deficits after surgery in symptomatic patients. Complete resection is not possible in intramedullary lipomas.