IMMU-61. Coexistent multiple sclerosis and glioma: diagnostic challenges, ambiguous correlation, and treatment dilemmas

Abstract BACKGROUND Coexistent multiple sclerosis (MS) and glioma is a rare and unique circumstance associated with uncertainty regarding the appropriate diagnostic evaluation and treatment given the lack of therapies that simultaneously target both diseases and the paucity of guidelines directing management. Distinguishing the two entities based on clinical and radiographic features alone can be misleading and histological confirmation becomes necessary. METHODS Here we report on a single-center cohort of five patients with concurrent diagnoses of MS and glioma. Patients were included regardless of which diagnosis they received first. RESULTS The average age of MS and glioma diagnoses in our cohort was 37 and 43 years, respectively, and the average time between diagnoses was 9.2 years. 2 of the 5 patients’ tumors developed adjacent to demyelinating plaques. 3 patients had also undergone 7 Tesla magnetic resonance (MR) imaging, and 3 patients were evaluated with MR spectroscopy. 3 patients were on disease-modifying treatments (DMTs) prior to the discovery of glioma. 1 of these patients continued and 1 patient discontinued DMT during chemotherapy and/or radiation; the third patient continued DMT during surveillance. None of the 5 patients experienced MS relapse or tumor growth during tumor treatment or surveillance. CONCLUSIONS The epidemiology of this cohort was concordant with the overall epidemiology of MS and glioma. We describe instances of nonspecific imaging findings that contributed to diagnostic uncertainty, including advanced imaging techniques, as well as gliomas that originated in close proximity to demyelinating lesions. Herein imaging and histopathologic characteristics, immunologic underpinnings, and treatment considerations are reviewed. Pitfalls in diagnosis of concomitant MS and glioma may lead to delayed diagnoses and influence surgical decisions. Based on this cohort, it is reasonable to continue DMT during tumor treatment and surveillance. However, this is a nuanced and individualized decision, and multidisciplinary discussions between the treating specialists remain essential.