BACKGROUND: Secondary neurolymphomatosis is a rare clinical condition that may be observed in patients with hematologic malignancies. Clinical findings can overlap with other conditions. Diagnosis can be obtained by magnetic resonance imaging (MRI) and imaging with positron emission tomography (PET) and confirmed by biopsy.

CASE REPORT: A 55-year-old male patient with known previous history of periocular non-Hodgkin’s lymphoma mucosa-associated lymphoid tissue (MALT) type presented reporting he had a focal soft-tissue swelling mass on the external side of the right arm, suspected for lipoma. US, MRI, and FDG PET/CT were performed, revealing malignant imaging characteristics of the lesion, suspected to be a neurolymphoma. A biopsy confirmed the nature of the lesion. No further sites of malignancy were detected on whole-body PET/CT.

CONCLUSIONS: Lymphomatous involvement of peripheral nerves may clinically overlap with other, more common, benign conditions; therefore, although it is rarer, this diagnosis has to be considered in patients with a clinical history of hematologic malignancies.

Keywords: Fluorodeoxyglucose F18, Lymphoma, Non-Hodgkin, Magnetic Resonance Imaging, Ultrasonography, Doppler, Biopsy, Lymphoma, B-Cell, Marginal Zone, Neurolymphomatosis, Peripheral Nervous System Neoplasms, Positron Emission Tomography Computed Tomography, Radial Neuropathy, Ultrasonography