Optic nerve infiltration revealing an extramedullary relapse of acute lymphoblastic leukemia in a child: A case report and review of the literature

Orbital involvement represents a relatively common manifestation in leukemia, in contrast to involvement of the optic nerve, uveal tract, and retina, which remains uncommon. Ocular manifestations are most often related to direct infiltration of ocular structures by leukemic cells. However, associated hematologic abnormalities, particularly anemia and hyperviscosity syndromes, may also contribute to ophthalmic complications.
Optic nerve infiltration is increasingly recognized as a significant manifestation of central nervous system (CNS) involvement in leukemia.
We report the case of a 15-year-old male patient with T-cell acute lymphoblastic leukemia (T-ALL), who developed an early neuromeningeal relapse five months after initiation of chemotherapy according to the MARALL 2006 protocol.
Clinically, the course was marked by the onset of right-sided unilateral blindness associated with ophthalmoplegia involving the superior and lateral rectus muscles, along with absent pupillary light reflexes. Bone marrow examination revealed 2% blasts, leading to classification of this relapse as early, group S2.
Brain computed tomography demonstrated passive tetra-ventricular hydrocephalus, associated with a thickened, enlarged, and tortuous appearance of the right optic nerve.
Salvage therapy was initiated according to the COPRALL 2007 relapse protocol. However, follow-up magnetic resonance imaging revealed progression of the intraorbital tumor process, with intracranial extension into the cavernous sinus.
Following disease progression, palliative chemotherapy was initiated.