Intraosseous arteriovenous malformation in a pediatric patient. 
An isolated tibial intraosseous arteriovenous malformation was diagnosed in a seven-year-old boy.  This malformation was not associated with any major clinical symptomatology except pain.  It had a paucity of physical findings and was not well visualized with conventional radiography.  It was not associated with any soft-tissue or cutaneous manifestations and it was entirely intramedullary, with minimal cortical involvement.  This case illustrates the value of magnetic resonance imaging in the localization of these lesions.  The absence of radiation exposure, coupled with the noninvasive nature, makes magnetic resonance imaging important in evaluating an intramedullary process in a pediatric patient.