Diencephalic syndrome as sign of tumor progression in a child with neurofibromatosis type 1 and optic pathway glioma: a case report.

ILLUSTRATIVE CASE: We describe the case of a 3-year-old child, diagnosed with familial neurofibromatosis type 1 (NF1) and asymptomatic optic pathway tumor at the age of two, who developed diencephalic syndrome (DS) due to tumor progression 1 year after diagnosis. Magnetic resonance imaging disclosed an enlarging hypothalamic contrast-enhanced mass. Because of the tumor progression, in terms of tumor volume and DS, chemotherapy (CT) treatment was started according to the international protocol for progressive low-grade glioma, with rapid clinical improvement in terms of gain weight and DS resolution. Interestingly, tumor volume was unchanged after CT.
CONCLUSIONS: This case report highlights the following facts: (1) optic pathway glioma (OPG) in young children with NF1 may have definitive growth potentials and thus, they are worth an accurate clinical follow-up; (2) also, OPG occurring in NF1 patients can be responsible for DS in case of hypothalamus involvement; (3) consequently, the child's growth pattern must be included among the clinical parameters, which must be specifically evaluated during the follow-up of children, with or without NF1, bearing an OPG; and, finally, (4) that DS can improve after CT, even in face of a stable tumor volume.