Concomitant ATTR and AL Cardiac Amyloidosis With Matching 99mTc-DPD Scintigraphy and 18F-Flutemetamol PET/CT

Two distinct types of systemic amyloidosis—transthyretin (ATTR) and light chain (AL)—account for the majority of cardiac amyloidosis (CA), which have been considered mutually exclusive. Diagnostic confusion can arise when both proteins are identified from an amyloid deposit. We present a rare occurrence of histopathologically confirmed concomitant ATTR and AL CA captured on 99m Tc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scan and 18 F-flutemetamol (FMM) PET/CT.