- Cancers can cause neuropathy thru a number of mechanisms
- Chemotherapy induced (e.g. vincristine)
- Direct invasion of any cancer into PNS
- Neurolymphomatosis: invasion of lymphomas cells into connective tissue around nerves
- Cancer induced vasculitis
- Paraneoplastic, where cancer induces antibodies against PNS
- Para-protein production (e.g. multiple myeloma, MGUS)
- Nutritional deficiencies or metabolic processes related to the cancer, or other co-existent issues (e.g. DM)
- Paraneoplastic: small cell lung cancer in particular; also breast, lymphoma, others
- Para-protein associated: Waldenstroms, lymphoma, Multiple Myeloma, POEMS, MGUS
- Neurolymphomatosis: an ucommon complication of lymphoma (5% of lymphomas) - in particular large B-cell lymphoma (DLBC most common)
- Neuropathic pain, often distal; numbness
- Can also have weakness when motor system involved
- Gait/balance problems - related to sensory neuropathy; autoimmune can sometimes affect cerebellum
- With neurolymphomatosis, can affect PNS or Cranial Nerves; pain is the most common Sx
- Symptoms related to underlying cancer - though neuropathy can appear before cancer detected
- Decreased distal sensation
- Inappropriate pain upon even light touch
- Impaired reflexes
- Sometimes weakness
- Findings related to underlying cancer