18F-Florbetapir PET/CT and 68Ga-FAPI PET/CT in a Case of Light Chain Amyloidosis With Predominant Multiple Tumor-Like Deposits

Abstract A 66-year-old man presented with multiple masses in different regions, including the left groin, back subcutaneous area, and lungs. Pathological examination confirmed localized amyloid deposits after 3 surgeries. Serum-free λ light chains were elevated. To evaluate systemic involvement, the patient underwent 18 F-Florbetapir PET/CT and 68 Ga-FAPI-04 PET/CT. Both scans showed increased uptake in multiple masses and nodules throughout the body. This report presents a rare case of light chain (AL) amyloidosis, primarily characterized by multiple localized tumor-like deposits with high activity on 18 F-Florbetapir PET/CT and 68 Ga-FAPI-04 PET/CT.