A novel OCT signature in leukemic papillopathy masquerading as autoimmune or infectious uveitis.

With therapeutic advances, central nervous system (CNS) involvement in leukemia has become more common. Leukemic optic disc infiltration, often a clinical diagnosis, can present as an isolated finding in primary or relapsed CNS disease and therefore requires early recognition. Not previously well appreciated, we report here signs of intraocular inflammation accompanying leukemic optic disc infiltration, suggesting infectious or non-infectious uveitis as an alternative diagnosis. We describe a novel optical coherence tomography (OCT) sign favoring leukemic infiltration. Retrospective consecutive case series of all leukemic patients with disc edema (5 patients, 6 eyes) presenting to the University of Michigan's Ocular Oncology Clinic between October 2019 and March 2020. We report five leukemic patients (6 eyes) who were evaluated for disc edema and vitritis and eventually diagnosed with leukemic papillopathy. All five patients initially had a bland lumbar puncture (LP), and all four patients who underwent magnetic resonance imaging (MRI) had no retrobulbar nerve involvement. Clinical findings included preserved visual acuity (n = 5 eyes, 83%), anterior chamber (AC) cell (n = 3 eyes, 50%), vitreous cell (n = 6 eyes, 100%), and retinal whitening (n = 4 eyes, 66%). In five eyes (83%), a diagnosis of infectious or non-infectious uveitis was initially considered. The OCT finding of inner retinal thickening and loss of inner retinal lamination with largely preserved outer retinal architecture helped point towards a leukemic infiltrative process emanating from the disc and spreading retrograde through the nerve fiber layer. These cases highlight the difficulty of distinguishing intraocular inflammation associated with leukemic papillopathy from infectious or non-infectious uveitis, especially considering bland LP and negative retrobulbar MRI signal in all our patients. We propose juxtapapillary inner retinal infiltration with the loss of inner retinal lamination and relative preservation of outer retinal architecture on OCT imaging as a finding that supports the diagnosis of leukemic papillopathy.