[Lymphoma in the peripheral nerves and muscles]

Non-Hodgkin lymphoma occurs and recurs in the peripheral nerves or skeletal muscles. Lymphoma cells infiltrate along anatomic structures. They typically do not invade the central nervous system from the cranial or peripheral nerve roots. Analysis of cerebrospinal fluid often does not lead to the diagnosis of neurolymphomatosis, even when meningeal infiltration is present. The concentration of soluble interleukin 2 (IL2) receptor, together with the findings of magnetic resonance imaging (MRI) and 18 fluoro-2-deoxyglucose positron emission tomography (FDG-PET) may contribute to the diagnosis, but not in early stages of the disease. Investigation of other tissues including bone marrow is sometimes useful. Differential diagnosis includes inflammatory demyelinating neuropathy in the nerve, and focal myositis in the muscle, in addition to other malignancies. Some lymphoma clones appear to have affinity for the peripheral nerves or muscle tissues.