Amyloidosis complicating idiopathic myelofibrosis.

An 84-year-old man presented with ankle edema, significant proteinuria, and mild impairment of renal function soon after treatment was started for idiopathic myelofibrosis. Renal amyloidosis was found on biopsy. The amyloid deposit was resistant to potassium permanganate treatment and showed no immunoreactivity to immunoglobulin light chains, beta-amyloid protein, or amyloid A component. A review of the literature showed that the occurrence of amyloidosis in idiopathic myelofibrosis is very rare, and the chemical nature of the amyloid involved remains unclear.