Long-term Survival after Resection of HER2+ Infiltrating Ductal Carcinoma Metastasis to the Brainstem.

The central nervous system is a common site of metastatic spread from neoplasms in distant organs, including breast, bone, and lung. The decision to surgically treat these metastatic lesions is often challenging, especially in the setting of systemic disease or when eloquent brain regions are involved. Treating metastatic disease in the brainstem can be technically difficult, and in many institutions, considered a contraindication to surgical intervention, given the relatively high risk of new postoperative neurological deficits. Herein, we report a case of metastatic ductal carcinoma of the breast with spread to the pontine-medullary junction that was treated with aggressive surgical resection and chronic hormonal therapy. After surgical excision of the brainstem lesion, the patient remained asymptomatic and was maintained on trastuzumab therapy over a 10-year follow-up period, with no radiographic or clinical evidence of recurrent disease. To our knowledge, this is the first report of a patient treated for a solitary metastasis to the brainstem with long-term survival.