Schilder disease or diffuse myelinoclastic sclerosis: is a rare disease that presents clinically as a pseudotumoural demyelinating lesion; and is more common in children.

Diffuse myelinoclastic sclerosis, sometimes referred to as "Schilder's disease", is a very infrequent neurodegenerative disease that presents clinically as pseudotumoural demyelinating lesions, that make its diagnosis difficult.

This is a primarily pediatric progressive metabolic disorder, demonstrating most commonly in boys between the ages of 5 and 15 and combining the characteristics of Addison's disease and diffuse myelinoclastic sclerosis (Schilder's disease).