Primary multifocal lymphoma of peripheral nervous system: case report and review of the literature.

Background: Primary lymphomas of peripheral nerves are extremely rare, and only a few cases have been reported.

Methods: We describe the clinical, neurophysiological, radiological, and pathological findings in a 61-year-old woman affected by primary multifocal lymphoma of the peripheral nervous system without systemic involvement.

Results: Fascicular left femoral nerve biopsy was decisive for the diagnosis of diffuse large B-cell non-Hodgkin lymphoma. Magnetic resonance imaging, fluorine-18 fluorodeoxyglucose positron emission tomography computed tomography, and nerve ultrasound contributed to the diagnosis.

Conclusions: Primary lymphoma of peripheral nerves (PLPNs) is a rare but potentially treatable condition, which is frequently misdiagnosed. In the literature, there are very few descriptions of PLPNs, most of which are mononeuropathies. The possibility of a neuropathy associated with lymphoma should be considered in patients with poor response to treatment and severe pain symptoms.