Diffuse Large B-Cell Lymphoma Recurring as Neurolymphomatosis on FDG PET/CT.

Two patients with diffuse large B-cell lymphoma relapsing as neurolymphomatosis diagnosed on FDG PET/CT are presented. Both patients were treated initially with chemotherapy and had a complete metabolic response. Patient 1 represented with lower-limb pain. An FDG PET/CT demonstrated intense uptake throughout the sciatic nerves bilaterally extending distally with relapse confirmed on biopsy. Patient 2 represented to hospital with worsening mobility, neuropathic pain, and facial asymmetry. An FDG PET/CT demonstrated relapse within the spinal cord, left sciatic nerve, and facial nerve branches. Neurolymphomatosis is an uncommon finding on FDG PET/CT and can be the only site of relapse.