Isolated paraneoplastic optic neuropathy associated with acute lymphoblastic leukemia and collapsin response-mediating protein (CRMP-5) autoantibody

We present a patient with leukemia associated with a CRMP-5-related paraneoplastic optic neuropathy (PON). A 30-year-old man with acute lymphoblastic leukemia (ALL) and complete chemotherapy suffered from a subacute painless visual loss in both eyes. His vision progressively decreased to 20/300 (OD) and 20/2000 (OS), respectively. Fundoscopy showed a massive disc edema (OS). Autoperimetry demonstrated generalized depression in both eyes. Magnetic resonance imaging (MRI) revealed swelling of left optic nerve at the orbital apex. Lumbar puncture examinations revealed a normal intracranial pressure and without tumor cell infiltration. CSF and serum for autoantibody examinations by using western blot showed a positive reaction to CRMP-5, but negative in myelin, voltage-dependent calcium channel alpha 1 (CACNA1), enolase and recoverin. Repeated lumbar puncture revealed a few immature myelomonocytic cells in CSF. Intravenous pulse therapy with Solu-Medrol associated with chemotherapy was administrated, the vision recovered to 20/40 (OD) and 20/60 (OS) within three days. One month later, his vision recovered to 20/20 (OD) and 20/30 (OS), as well as disc edema in left eye completely resolved. Paraneoplastic optic neuropathy should be in the differential considerations of disc edema in patients with malignancy.