Resolution of diabetes insipidus following gamma knife surgery for a solitary metastasis to the pituitary stalk. Case report.

The authors present the case of a 58-year-old woman who presented with symptoms of diabetes insipidus (DI) 1 year after she was found to have a Stage 3 (of 4) estrogen receptor-positive infiltrating ductal adenocarcinoma of the left breast with pulmonary and bone metastases. Magnetic resonance images demonstrated a solitary site of metastasis in the patient's pituitary stalk, and gamma knife surgery (GKS) was performed to treat the lesion. Three months after GKS the patient was able to reduce the medication she required for the DI. There was no evidence of pituitary failure and no negative effect on her vision.