December 8, 2008
A 23-year-old woman presenting with subacute onset of right face, arm, and leg weakness.
Tumefactive Demyelinating Lesion
- Commonly seen in young and middle-aged women. Pathologically, the lesions are indistinguishable from typical multiple sclerosis plaques, and sometimes imaging and histological features mimic high grade gliomas.
- Dilated vascular structures seen running centrally within the lesions on T2 echoplanar or SW images represent dilated veins draining toward distended subependymal veins.
- Cerebral blood volume is lower than in contralateral normal-appearing white matter and less than that found in high-grade gliomas and lymphomas.
- MR spectroscopy may be useful in diagnosis by demonstrating elevation of glutamate/glutamine peaks (2.1 ' 2.5 ppm); elevation of these peaks is typically not seen in high grade neoplasms.
- Most patients respond favorably to corticosteroid therapy and do not progress to multiple sclerosis .
