A case of amyloidosis of the tongue associated with long-term dialysis

We describe a case of amyloidosis of the tongue that developed after long-term hemodialysis (HD) therapy. A 70-year-old man was referred to our department because of spontaneous pain of the left border of the tongue. Firm and waxy white-yellow multinodular lesions were present. Biopsy of a painful lesion histopathologically revealed amyloidosis of the tongue. The patient had been given a diagnosis of chronic renal failure in 1968 and had received HD therapy since 1974. He had suffered from carpal tunnel syndrome (CTS) on the right side in 1986 and on the left side in 1988. He also had dysfunction of both shoulder joints in 1991; amyloid deposits were removed surgically. The serum beta 2-microglobulin level was elevated. This case was therefore diagnosed as HD-associated amyloidosis (HDaA) involving the tongue. Beta 2-microglobulin is a normally occurring protein that is not removed by HD and accumulates in the plasma. It forms amyloid deposits, particularly in the bones and joints and is often associated with CTS with joint dysfunction. Tongue involvement is rare. HDaA is one of the complications of long-term HD. Renal transplantation is the only radical treatment available for HDaA. Because patients with HDaA are increasing, amyloid deposits in oral tissue are likely to be encountered.