Background: Polyneuropathy is associated with several pathological conditions. Amyloidosis is a less common cause of polyneuropathy. Amyloidosis is caused by the accumulation of insoluble protein fibrils (amyloid) in the extracellular matrix. Primary systemic amyloidosis is caused by B-lymphocyte dyscrasia. Polyneuropathy is the first sign of primary systemic amyloidosis in about 20% of the cases, and is characterised by relentless progression, painfulness, and prominent symptoms of autonomic neuropathy.
Material and methods: We describe three cases of primary systemic amyloidosis that started with polyneuropathy.
Results: The diagnosis of primary systemic amyloidosis is often delayed more than two years after the onset of polyneuropathy. Biopsy of rectum, fat tissue, bone marrow, or peripheral nerve are diagnostic tools.
Interpretation: The survival of non-treated patients is about 18 months after the diagnosis. With chemotherapy the survival is prolonged to approximately 38 months.