Unusual Sanctuary Site (Central Nervous System) Metastases in Gastrointestinal Stromal Tumor Patients

Gastrointestinal Stromal Tumor (GIST) metastases occur in 18%47% of patients and most commonly involve the liver and peritoneum.  Central Nervous System (CNS) and other sanctuary site metastases are rare, with only limited single patient case reports available in the literature. Given the availability of multiple effective treatments and longer life expectancy in patients with metastatic GIST, there is an increased likelihood of metastases to sanctuary sites including the CNS. We sought to characterize three GIST patients who developed these rare sanctuary site metastases between 2017-2018 during their course of therapy and compare their clinical features and molecular profiles, to add to current knowledge and highlight the need for clinicians to consider sanctuary site metastases, particularly in patients presenting with new symptoms