Tumefactive acute disseminated encephalomyelitis.

Tumefactive demyelinating lesions are tumour-like presentations of acute demyelinating lesions. They have been described with multiple sclerosis only and not with other varieties of acquired demyelination like acute disseminated encephalomyelitis (ADEM). The uncertainty about the diagnosis at the onset of the disease in tumefactive ADEM makes it important that the physicians should be aware of this entity. Various radiological similarities with more sinister lesions like central nervous system gliomas or lymphomas may lead to this confusion. Appropriate supportive treatment with steroids and follow up is required in these cases to avoid unnecessary interventions.