Evaluation of Neoplastic Involvement of Brachial and Lumbosacral PlexusImaging Aspects

Traditionally, the regions of brachial and lumbosacral plexi have been difficult to evaluate, both by physical examination and conventional radiography. Presenting symptoms of plexus involvement may include pain, paresthesia, focal weakness, sensory deficits, and muscle atrophy. The symptomatology as well as electrodiagnostic studies are nonspecific and many conditions, such as mechanical compromise of the pathway by a benign process, inflammation, and infiltration by a neoplasm originating or metastatic to the region of plexi share similar features and cannot be differentiated. A general term "brachial or lumbosacral plexopathy" is universally used, to describe a variety of clinical syndromes, including tumor infiltration, neuritis, postsurgical, and postradiation changes as well as idiopathic conditions. Significant progress in detection and assessment of the extent of plexus disease has been made after introduction of computed tomography (CT). Further anatomical detail and tissue characteristics have been provided by magnetic resonance imaging (MRI). However, in spite of valuable contribution from both imaging methods, the plexi frequently present a challenging problem for a clinician as well as for a radiologist.