NI-19 A case of Leber’s hereditary optic neuropathy with diffuse white matter changes mimicking gliomatosis cerebri

BACKGROUND: Leber’s hereditary optic neuropathy (LHON) is a mitochondrial disease characterized by bilateral severe subacute central vision loss and a mutation in the mitochondrial DNA (mtDNA). The cranial magnetic resonance imaging (MRI) of LHON patients varies from subtle to multiple white matter changes. However, they rarely present with diffuse infiltrative white matter changes. CASE REPORT: We report a case with diffuse white matter changes mimicking gliomatosis cerebri (GC). The histological findings included only mild glial hyperplasia without immunohistochemical positivity supporting the diagnosis of glial tumors. Analysis of mtDNA obtained from the blood and brain tissue revealed mutation of m.11778G>A in the NADH dehydrogenase 4 gene, which confirmed the case as LHON. Immunohistochemistry of the brain tissue revealed 8-hydroxy-2’-deoxyguanosine positivity, suggesting the presence of oxidative stress. CONCLUSION: LHON is extremely difficult to diagnose unless we suspect or know the disease. The present case brings attention not only to LHON but other mtDNA mutated diseases that need to be considered with diffuse white matter changes or GC.