Coexistence of multiple sclerosis and brain tumors: a literature review.

Concurrent development of primary brain tumors and multiple sclerosis is quite rare. Only a few dozens of such comorbidity have been reported. Nevertheless, given the fact that such pathologies are characterized by similar clinical picture and neuroimaging findings, issues about diagnosis and differential diagnosis of such conditions often arise, which makes the problem relevant. A literature review was conducted using PubMed, by selecting articles on concurrent multiple sclerosis and brain tumors, particularly glial origin tumors, over the past 20 years (1989 to 2019). The search was performed in English, Russian, and Ukrainian using the following key words and terms: comorbidity, concomitance, multiple sclerosis, brain tumor, glioma, astrocytoma, glioblastoma. The analysis included all articles on etiology, pathogenesis, clinical picture, diagnosis, differential diagnosis, neuroimaging, and pathomorphological assessment. After identifying all the articles that met the inclusion criteria and removing duplicate data, 35 literature sources on concurrent primary brain tumors and multiple sclerosis were selected. The conclusion on whether concurrent primary brain tumors and multiple sclerosis develop randomly or have common pathophysiological mechanisms is still under discussion. Potential causes of pathogenesis of both diseases include viral infection, chronic inflammation, neoplastic transformation, and involvement of neurotropic growth factors. The likelihood that two processes, demyelinating and neoplastic, can develop in parallel will never be underestimated. In such cases, strong clinical suspicion arises due to atypical clinical picture characterized by aggressive and rapidly growing neurological symptoms such as aphasia, spastic hemiparesis, epileptic seizures, or signs of intracranial hypertension. In MRI diagnosis, pathological findings such as single lesion of more than 2 cm; mass effect, edema, signal amplification in the form of ring-shaped shadow are the reasons for a more thorough examination and applying additional diagnostic methods: CT, MR spectroscopy, PET, CSF tests to determine oligoclonal antibodies and other markers content, cerebral biopsy. According to the literature, cases of concurrent primary brain tumors and multiple sclerosis are rare though described. Atypical clinical signs, neuroimaging data, and cerebral biopsy which is currently considered as the only method for making accurate diagnosis are helpful in the diagnostic process.