Not All That Glows Is Cancer: Ga-68 FAPI PET/CT Uptake in Eosinophilic Esophagitis

A 70-year-old man with dysphagia since 2 months, underwent endoscopy, showing distal esophageal edema and furrows. Biopsy was negative for malignancy. F-18 FDG PET/CT showed low-grade distal esophageal uptake with mild smooth wall-thickening on CT scan. Ga-68 FAPI PET/CT was further performed to substantiate diagnosis and delineate repeat biopsy site, which exhibited intense, diffuse esophageal uptake, mimicking malignancy. However, repeat biopsy confirmed eosinophilic esophagitis, conjugated with peripheral eosinophilia (13.6%) and elevated absolute eosinophil count (801 cells/μL). This case, therefore, highlights a false-positive Ga-68 FAPI PET/CT finding in inflammatory esophageal diseases and underscores the need for multimodal correlation to prevent misdiagnosis.