An Extensive Atypical Systemic Light Chain Amyloidosis With Undetectable Plasma Cell Dyscrasia: A Case Report

Thouraya Soualah

Abstract 

Background: Light-chain amyloidosis (AL amyloidosis) is a rare, debilitating, heterogeneous, and multisystemic disorder that is often fatal in the absence of treatment. This is because of the conversion of light chains (LCs) produced by plasma cell dyscarasia from their soluble state into organized fibrillar aggregates, resulting in progressive organ damage and dysfunction. The clinical features of the disease are nonspecific and depend on the type of organ affected. Overall prognosis depends on several clinical, laboratory, and pathological parameters. Case presentation: A young Algerian man presenting with the diagnostic challenge of atypical extensive systemic amyloidosis initially presenting with severe neurological manifestations despite a lower burden light chain level and undetected plasma cell dyscarasia that developed over 10 years. Conclusion: Atypical clinical presentation, undetectable plasma cell dyscarasia, and unusual disease evolution led to delayed diagnosis and devastating complications in the patient at the time of diagnosis. A very high clinical suspicion with a combination of several laboratory and histopathological tests is required to confirm the diagnosis. Although biopsy is the gold standard for the diagnosis of AL amyloidosis and confirmation of the involvement of each organ, noninvasive techniques with high sensitivity and specificity have been used.
 

Keywords: Systemic amyloidosis; Light chain amyloidosis (AL amyloidosis); Light chain burden level; Plasma cell dyscarasia; Monoclonal gammopathy.

Article DOI: https://doi.org/10.70620/CRROA/v6i1/2025/149