Magnetic resonance appearance of peripheral nerve sheath tumors.
Magnetic resonance imaging (MRI) was used to evaluate 22 histologically proven peripheral nerve sheath tumors, approximately two-thirds of which arose in the lower extremity. The histologic distribution was as follows: 12 schwannomas, 7 neurofibromas, and 3 malignant peripheral nerve sheath tumors (2 of which occurred in patients with neurofibromatosis). Most lesions demonstrated an intermediate to moderately bright signal on T1-weighted images and were minimally inhomogeneous. All lesions were moderately bright on proton-density-weighted images and bright on T2-weighted images, again with variable inhomogeneity. The extent of the tumor was best assessed on proton-density- and T2-weighted images. Smooth margins were noted in 19 lesions. Of the 3 remaining lesions, 2 were malignant (but had been subjected to biopsy prior to MRI), and the other lesion was a plexiform neurofibroma. MRI accurately determined the relationship between the lesion and the adjacent neurovascular structures and muscles, thereby assisting surgical management. On MRI, 5 lesions demonstrated coexistent subtle muscle atrophy along the longitudinal axis of surrounding or distally innervated musculature. This latter finding, together with the presence of a tumor in the vicinity of a large nerve trunk, suggests a peripheral nerve sheath neoplasm.
Stull
M A
MA
Department of Radiology, Georgetown University Medical Center, Washington, DC.
Moser
R P
RP
Kransdorf
M J
MJ
Bogumill
G P
GP
Nelson
M C
MC
D000328:Adult; D005121:Extremities; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009442:Neurilemmoma / Q000175:diagnosis*; D009455:Neurofibroma / Q000175:diagnosis*; D009456:Neurofibromatosis 1 / Q000175:diagnosis; D010524:Peripheral Nervous System Neoplasms / Q000175:diagnosis*; D012983:Soft Tissue Neoplasms / Q000175:diagnosis*