Neurolymphomatosis; a case report.

We present a case of indolent neurolymphomatosis in a 55-year-old male patient with worsening pain and weakness in his right leg over the past few months. The patient has a past medical history of type II diabetes mellitus, four-year history of worsening left foot drop, left lower limb pain and weakness attributed to diabetic amyotrophy, and back pain. The new right-sided symptoms prompted further imaging which revealed a left sciatic nerve mass which was biopsied. Initial biopsy results were inconclusive. F-FDG PET/CT revealed the full extent of this patient's disease and helped plan for a more representative biopsy site, which finally established a diagnosis of diffuse large B-cell lymphoma involving the lumbosacral nerve roots. The patient underwent a course of chemotherapy. F-FDG PET/CT was ordered again at the end of treatment showing partial response to therapy. He underwent radiation therapy to the site of residual disease, with complete metabolic response of lesions on follow up PET CT.