Tumefactive demyelinating lesions: Characteristics of individual lesions, individual patients, or a unique disease entity?

Whether or not recurrent tumefactive demyelinating lesions are a unique form of CNS demyelinating disease or part of the continuum of multiple sclerosis is a question raised by the case report on which this commentary is based. Detailed review and immunopathologic study of biopsy material may not only confirm or refute a diagnosis of demyelinating disease, but potentially uncover unique features that may assist in understanding pathophysiology and nosology of rare cases with recurrent tumefactive demyelination.