Abstract
This study reports the first case of solitary brain metastasis from myxoid pleomorphic liposarcoma (MPLS) evaluated using (18)F-FAPI-04 PET/CT. The imaging revealed a distinct "Halo Sign," reflecting the infiltration characteristics of cancer-associated fibroblasts (CAFs) within this rare tumor type. These findings highlight the utility of (18)F-FAPI-04 PET/CT in characterizing tumor heterogeneity and underscore its potential to improve the diagnosis of rare brain metastases while informing future therapeutic strategies.