Atypical Amyloidosis: Diagnostic Challenges and the Role of Immunoelectron Microscopy in Diagnosis

Abstract

Renal AL-amyloidosis is usually lambda-light-chain-related, particularly lambda type 6. Kappa-light-chain-related renal amyloidosis is a rare entity. Relatively few cases have been reported in the literature. The pathologic findings in some of these cases may mimic other disease processes. It is important to recognize the different morphologic expressions of this entity in order to render the right diagnosis. The authors discuss one such case in which the initial pathologic impression was erroneous and, upon further studies, including ultrastructural immunogold labeling, the diagnosis of kappa-light-chain-related renal amyloidosis was established.