458 Atypical Hepatic ALECT2 Amyloidosis with Isolated Linear Vascular Deposition: Beyond the Globular Pattern

Introduction/Objective Leukocyte cell-derived chemotaxin 2 (ALECT2) amyloidosis is a rare and increasingly recognized form of systemic amyloidosis that differs morphologically from AL and AA types, typically presenting in the liver as globular amyloid deposits along sinusoids and within portal tracts. We report an atypical case of hepatic ALECT2 in which amyloid deposition was confined to vascular/perivascular regions, without the classic globular morphology observed. Methods/Case Report A 69-year-old Hispanic woman underwent liver transplantation for NASH cirrhosis. Explanted liver showed cirrhosis without overt steatosis. Notably, eosinophilic, amorphous extracellular material was observed in portal/septal vasculature, especially venular branches, with no globular deposition pattern identified. Congo red staining confirmed the same vascular distribution, and polarized light microscopy demonstrated classic apple-green birefringence. Mass spectrometry confirmed ALECT2-type amyloid. There was no clinical evidence of cardiac involvement or plasma cell dyscrasia. Results NA Conclusion This case emphasizes the importance of recognizing non-classical morphologic variants of ALECT2 amyloidosis. Overreliance on globular morphology as a diagnostic clue for ALECT2 may result in misclassifying cases with isolated linear vascular patterns as AL or AA amyloidosis, potentially resulting in unnecessary and harmful treatments. Awareness of vascular-restricted deposition of ALECT2 and the use of confirmatory mass spectrometry are critical for accurate diagnosis and appropriate clinical management.