Solitary sciatic nerve lymphoma as an initial manifestation of diffuse neurolymphomatosis - Case report and review of the literature

Solitary peripheral nerve lymphomas are exceedingly rare primary manifestat ions of diffuse peripheral nervous system or central nervous system (CNS) l ymphomatosis. A 52-pear-old man presented with progressive weakness in gast rocnemius and anterior tibial muscle function, which was associated with ra diating pain in the right leg. Magnetic resonance imaging studies revealed a solitary fusiform tumor, extending from the sciatic nerve, at the level o f the lesser trochanter of the femur, into the posterior tibial nerve below the popliteal fossa. Intraoperative gross examination found that the tumor diffusely expanded the nerve, but did not extend from or into surrounding muscle or tendons. The final histological diagnosis was a solitary extranod al lymphoma (Burkittlike high-grade B-cen lymphoma). Postoperative staging did not reveal evidence of lymphomatous involvement of other organs, but ad ditional chemo- and radiotherapies were administered. Four months after the surgical biopsy, the patient presented with a right facial nerve palsy. Th e results of cytological examination of cerebrospinal fluid were positive f or the presence of atypical lymphocytes, which was consistent with apparent ly progressive neurolymphomatosis; however, the results of radiological stu dies were negative for systemic progression. The patient underwent intrathe cal chemotherapy followed by systemic myelosuppressive chemotherapy with bo ne marrow rescue, but died of respiratory failure while still receiving tre atment. Postmortem examination revealed extensive lymphomatosis in the peri pheral nerves and spinal nerve roots without evidence of cranial nerve, CNS , or other organ system involvement. The aggressive biological characterist ics of these tumors, their management, and pertinent literature are reviewe d.