Neurologic manifestations of neoplastic and radiation-induced plexopathies.

Metastatic plexopathy is often a disabling accompaniment of advanced systemic cancer, and may involve any of the peripheral nerve plexuses. Brachial plexopathy most commonly occurs in carcinoma of the breast and lung; lumbosacral plexopathy is most common with colorectal and gynecologic tumors, sarcomas, and lymphomas. Neoplastic plexopathy is often characterized initially by severe, unrelenting pain followed by development of weakness and focal sensory disturbances. In previously treated patients, the main differential diagnostic consideration is radiation-induced plexopathy, which can be difficult to distinguish from tumor plexopathy. Diagnosis is usually made following an analysis of the clinical, neuroimaging, and electrophysiologic features. Treatment of metastatic plexopathy has included surgical resection of tumor in selected cases, radiotherapy to the plexus, systemic chemotherapy, interventional pain management procedures, and symptomatic treatment. These measures often offer temporary (months) relief or improvement. Physicians treating these patients should focus on effective management of pain and prevention of complications of immobility produced by the neuromuscular dysfunction.