Leukocyte Cell-Derived Chemotaxin-2 Amyloidosis (ALECT2) in a Patient With Lung Adenocarcinoma: An Autopsy Report and Literature Review

Amyloidosis caused by deposition of leukocyte cell-derived chemotaxin-2 amyloidosis (ALECT2) is the most recently described form of systemic amyloidosis and has quickly emerged as a common and possibly underdiagnosed cause of slowly declining renal function, particularly in patients of Hispanic ancestry. We describe the autopsy findings in a 70-year-old Hispanic woman who died of metastatic lung adenocarcinoma and was incidentally found to have extensive amyloid deposition in the kidneys, liver, spleen, adrenal glands, small intestine, gallbladder, lungs, bilateral ovaries, and uterus. The type of amyloid was confirmed to be ALECT2 by mass spectrometry. The pattern of amyloid deposition in the kidneys and the liver was typical for what has been described for ALECT2. In addition, a unique pattern of amyloid deposition was observed in spleen, adrenal glands, small intestine, gallbladder, lungs, ovaries, and uterus. The pattern of amyloid deposition in ALECT2 is distinct from amyloid A and amyloid light-chain and needs to be recognized to avoid misdiagnosis as amyloid light-chain or amyloid A amyloidosis. After recognition, an accurate diagnosis by mass spectrometry and/or immunohistochemical staining is essential to guide treatment and avoid toxic therapies.