MR imaging of multiple sclerosis simulating brain tumor.

Multiple sclerosis (MS) may sometimes present as a mass lesion that is clinically and radiologically indistinguishable from brain tumor. The initial recognition of such cases is essential to avoid a surgical intervention and supplementary treatment. Sometimes areas adjacent to a tumor may present similar histopathological features with non-neoplastic demyelinating lesions. Thus, the proper preparation of the specimen is the key for correct pathological diagnosis. We report a case of MS with large cranial involvement showing a mass effect. The operative procedure associated with medical treatment was performed, and a good result was obtained. Our case presentation and others in the literature suggest strategies for detecting MS presenting as a mass lesion.