Neuropathies associated with malignancy.

Patients with malignancy can develop peripheral neuropathies as (1) a direct effect of the cancer by invasion or compression of nerves, (2) a remote or paraneoplastic effect, or (3) an iatrogenic effect of treatment. Focal or multifocal cranial neuropathies, radiculopathies, and plexopathies typically result from tumor infiltration, herpes zoster infection, or radiation-induced injury. Sensorimotor polyneuropathies are the most frequently encountered peripheral nerve syndromes, but motor neuropathies, sensory neuronopathies, polyradiculoneuropathies, and autonomic neuropathies can also occur. Although uncommon, paraneoplastic mechanisms should be considered in a patient with malignancy and an associated peripheral nerve disorder, especially in the setting of small-cell lung cancer or lymphoproliferative cancer. Toxic neuropathies occur with exposure to several chemotherapeutic agents, including the vinca alkaloids, cisplatin, taxanes, and suramin. These neuropathies are usually dose-related, sensory-predominant, and at least partially reversible, with an axonopathic or ganglionopathic mechanism. Suramin is unique in causing subacute, demyelinating polyradiculoneuropathy.