hi, Thanks for writing in. Plexiform neurofibromas in strategic locations are to be removed through skilled surgery. It is important to know the size and extension of the tumor and if there are any cancerous areas which are developing within. In that case, you must consult an oncosurgeon and vascular surgeon and know the implications of the tumor causing pressure effects or the rare possibility of the tumor infiltrating the arteries. Medicines are not a treatment option for these tumors. Though the tumors are usually benign and harmless, increase in size with time and malignant transformation cannot be entirely ruled out in your grandson. That might take years to happen but it can be easily prevented by getting treated through surgery at present.