Light chain (AL) amyloidosis

This code represents a systemic disorder characterized by the abnormal deposition of insoluble light chain protein fragments in various organs and tissues. This accumulation disrupts normal organ function, leading to a range of symptoms depending on the affected sites. It is the most common form of systemic amyloidosis.

Apply this code when documentation confirms a diagnosis of primary amyloidosis, specifically identified as being caused by immunoglobulin light chains. This diagnosis is typically supported by biopsy results demonstrating amyloid deposits with positive immunohistochemical staining for lambda or kappa light chains, often in conjunction with evidence of a monoclonal gammopathy.

• Distinguish from other forms of amyloidosis (e.g., transthyretin-related, secondary) which have different codes.
• Always look for definitive diagnostic statements or pathology reports confirming AL type.
• Code any associated organ manifestations (e.g., cardiomyopathy, nephropathy) as secondary diagnoses.