Background: Primary localized cutaneous nodular amyloidosis (PLCNA) is a rare disease, and its pathogenesis of amyloid deposition is still unknown.
Objective: The purpose of this study was to know the origin of amyloid in PLCNA.
Methods: Water-soluble amyloid fibrils were isolated from the skin and resolved on SDS-PAGE, then subjected to immunoblot analysis.
Results: The major amyloid fibril protein was a 29-kD peptide which reacted with both anti-lambda- and anti-kappa-light-chain antibodies.
Conclusion: Amyloids in this particular case of PLCNA are derived from the polyclonal immunoglobulin light chain and some cases of PLCNA could be reactive diseases rather than neoplastic ones.