Amyloidosis complicating hairy cell leukemia.

A patient development renal failure following a ten-year affliction with hairy cell leukemia. Renal biopsy showed amyloidosis, characterized by the presence of potassium permagnate-sensitive congophilia in deposits within glomeruli and renal blood vessels. Electron microscopy demonstrated amyloid fibrils. Immunohistochemical technics showed the deposits were composed of AA Protein. These Congo red staining properties, and the presence of AA Protein are characteristic of deposits in secondary amyloidosis. Secondary amyloidosis is a known complication of many chronic illnesses. This report shows it may concur with hairy cell leukemia, and that amyloidosis should be considered in the differential diagnosis of renal failure in patients with hairy cell leukemia.