Optic nerve tumor in tuberous sclerosis complex is not responsive to sirolimus

A 12-year-old girl with clinically established tuberous sclerosis complex, and without signs of neurofibromatosis type 1, developed a right retro-ocular optic nerve tumor. After rapid growth for 1 year after its discovery, the optic nerve tumor demonstrated modest progression. The patient received the mammalian target of rapamycin inhibitor, sirolimus, for recurrent subependymal giant cell brain tumors. Although her left ventricular subependymal giant cell tumor demonstrated a 49% reduction in volume, the optic nerve tumor did not respond, and even underwent slight (6%) growth during the 16-month treatment. The quality of this child's vision has remained normal in both eyes, and she is otherwise asymptomatic with regard to the optic nerve tumor.