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.

NCOG-34. A DESCRIPTIVE ANALYSIS OF GLIOMATOSIS CEREBRI CASES, COMPARED ACCORDING TO IDH STATUS

Gliomatosis cerebri (GC) is a controversial entity no longer recognized as a histopathologic-defined diagnosis, characterized by diffuse, commonly bilateral infiltration of cerebral hemispheres. The purpose of this report is to describe clinical, imaging, patient-reported outcomes (PRO’s) and pathologic characteristics of clinically-defined cases from a large natural history study cohort (N=769). Of 19 patients, 10 male, 16 white, mean age at diagnosis 43 (19-70), seventeen presented as primary GC, while 2 developed GC after treatment. Ten patients were IDH-WT, 7 IDH-M, and 2 IDH undetermined. The majority (7/10) IDH-WT patients presented acutely (5 with seizures), whereas, 3 had a protracted presentation of 2 weeks-3months with 6/10 having enhancing tumors and 8/10 undergoing biopsy only. On histopathologic review, 4 were anaplastic astrocytoma (AA), 3 GBMs, 2 grade II astrocytoma, and 1 histone-mutated glioma. Nearly all (9/10) IDH-WT patients received radiation with concurrent and adjuvant temozolomide. 7/10 IDH-WT patients had a survival of only 1.5yrs or less from diagnosis. Of the 7 IDH-M patients, 4 had protracted presentations of 1 month-5 years. 6/7 had non-enhancing tumors at presentation. 4 had biopsy only and 3 underwent partial resection. 3 were AA, 2 grade II astrocytoma, 1 grade II oligodendroglioma, and 1 grade IV astrocytoma. 3/7 received radiation with concurrent and adjuvant temozolomide, 3/7 chemotherapy alone, and 1 RT alone. All 7 IDH-M patients survived 3+ years from diagnosis (range 3-10+ yrs). Both patients who developed GC later, were IDH-M, with prolonged survival (3.5yrs and the other still alive 10+yrs). PRO's at time of last clinical assessment revealed GC patients to be highly symptomatic with mean overall symptom burden, depression, and anxiety higher than our overall glioma population. GC patients have a varied clinical course mandating further investigation to enable better prognostic definition to refine treatments based on the varying clinical and molecular characteristics.

T2/FLAIR hyperintensity in the mesial temporal lobe: challenging differential diagnosis

: T2/FLAIR hyperintensity in the mesial temporal lobe is the most common MR finding of herpes simplex encephalitis but may be observed in other infectious and non-infectious diseases. The former includes herpes human virus 6 encephalitis, Japanese encephalitis, and neurosyphilis, and the latter autoimmune encephalitis, gliomatosis cerebri, bilateral or paradoxical posterior cerebral artery infarction, status epilepticus, and hippocampal sclerosis. Thus, T2/FLAIR hyperintensity in the mesial temporal lobe is not a disease-specific magnetic resonance imaging finding, and these conditions must be differentiated to ensure proper treatment. We review diseases that are presented with T2/FLAIR hyperintensity in the mesial temporal lobe and provide a helpful flow chart based on clinical and radiologic features.

Leber’s hereditary optic neuropathy with diffuse white matter changes mimicking gliomatosis cerebri: illustrative case

BACKGROUIND 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 findings on cranial magnetic resonance imaging of patients with LHON vary from subtle to multiple white matter changes. However, they rarely present with diffuse infiltrative white matter changes. OBSERVATIONS The authors reported 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. LESSONS LHON is extremely difficult to diagnose unless one suspects or knows the disease. The present case brings attention not only to LHON but also to other mtDNA-mutated diseases that need to be considered with diffuse white matter changes or GC.

Gliomatosis Cerebri Growth Pattern: Association of Differential First-Line Treatment with Overall Survival in WHO Grade II and III Gliomas

<b><i>Introduction:</i></b> Gliomatosis cerebri (GC) is defined by diffuse, widespread glial tumor growth affecting three or more cerebral lobes. Previous studies in gliomas found no distinct histological or molecular GC subtype, yet the presence of GC is associated with worse median overall survival (OS). Here, we explored whether differing therapeutic strategies in first-line treatment could account for this. <b><i>Methods:</i></b> From our University Cancer Center database, 47 patients with histological diagnosis of WHO grade II or III glioma and GC imaging pattern were identified. GC criteria were confirmed by independent review. Patients with WHO grade II or III glioma with non-GC pattern served as control cohort (<i>n</i> = 343). <b><i>Results:</i></b> Within the GC patient cohort, lower WHO grade, mutated isocitrate dehydrogenase 1 (IDH1) status, and absence of contrast enhancement were associated with better OS. Compared to the control cohort, patients with GC had significantly shorter OS independent of histological diagnosis or IDH1 mutation status. Patients with GC preferentially received chemotherapy alone (62 vs. 18%), and less frequently radiochemotherapy (21 vs. 27%). OS was significantly shorter in the GC cohort compared to the non-GC cohort both for chemotherapy (3.9 vs. 7.6 years, <i>p</i> = 0.0085) and for combined radiochemotherapy (1.1 vs. 8.4 years, <i>p</i> &#x3c; 0.0001). However, when only patients who received biopsy plus chemotherapy were analyzed, the differences lost statistical significance (3.5 vs. 6.6 years, <i>p</i> = 0.196). <b><i>Conclusion:</i></b> We found major differences in the selection of first-line therapies of GC versus non-GC patients. Our results suggest that these differences may partly account for the worse prognosis of GC patients.