Background: Diencephalic syndrome (DS) can cause failure to thrive in pediatrics, which is mostly found in optic pathway gliomas (OPGs) patients. OPGs patients with DS always show a poor outcome.
Case presentation: We present the case of an OPG patient with DS who got a spontaneous regression without any treatment. A 6-month-old girl presented with failure to thrive for two months and visual dysfunction with bilateral horizontal nystagmus. MRI demonstrated a 42mm*37mm*36mm enhanced and lobulated lesion located in the sellar region with a clear boundary with surrounding tissues. OPG and DS was diagnosed according to her radiological examination and manifestation. Conservative follow-up was given. There was a spontaneous decrease in tumor size during follow-up. Symptom improves and the patient continues to have a good quality of life despite a moderate dysfunction of her left eye.
Conclusions: Conservative observation can be used as a treatment for some OPG patients, body weight may be a marker of the growth of tumor in OPG patients with DS.