Peripheral neuropathies in a context of systemic malignancy may have a different cause and can manifest in various stages of development of malignancy. They can be a direct effect of the primary malig nancy, a paraneoplastic syndrome, or a treatment complication.
Malignant neoplasms may infiltrate or compress peripheral nerves or roots, causing various sensory and motor symptoms. Paraneoplastic syn dromes are rare, but they can precede a manifestation of the cancer itself.
The most common is subacute sensory neuronopathy, sensorimotor neuropathies are less common. Neuropathies may also be an indirect consequence of a dysimmune mechanism, for instance in patients with lymphomas or vasculitis.
Peripheral neurotoxicity is a side effect of many chemotherapeutic agents and can affect the nerve fibers or the neuronal bodies. This side effect frequently represents one of their dose-limiting factors in cancer treatment.
Both brachial and lumbosacral plexopathies may develop as a complication of radiotherapy.