Key Information
Source
Year
2026
summary/abstract
Abstract
Background
Grade 2 or 3 uptake on 99mTc-pyrophosphate scintigraphy is a cornerstone for diagnosing transthyretin amyloidosis. However, light-chain amyloidosis can infrequently mimic this pattern, causing diagnostic error.
Case Summary
A 53-year-old man with heart failure presented with left ventricular hypertrophy and elevated biomarkers. Cardiac magnetic resonance suggested infiltration. 99mTc-pyrophosphate scintigraphy showed intense grade 3 (Perugini) uptake. However, immunofixation revealed an immunoglobulin G lambda clone. Fat and duodenal biopsies confirmed systemic light-chain amyloidosis (AL).