A case of idiopathic salivary hyperamylasemia

The elevation of serum amylase is generally associated with diseases of the pancreas or salivary glands. However, hyperamylasemia has also been noted to occur in a variety of conditions, such as amylaseproducing cancers, chronic viral liver disease, macroamylase, and after various surgical procedures. We describe a man in his fifties who was given a diagnosis of idiopathic salivary hyperamylasemia. He was referred to our clinic because of hyperamylasemia lasting over a 2-year-period, during which the patient remained asymptomatic. Blood examination at presentation revealed pancreatic and salivary amylase levels of 47 U/L and 626 U/L, respectively. No abnormal findings except for a kidney stone and renal atrophy were detected on further examinations, including abdominal ultrasonography, magnetic resonance cholangiopancreatography, magnetic resonance imaging of the salivary glands, and positron emission tomography-computed tomography. Furthermore, macroamylase was not detected on electrophoresis of serum amylase. On the basis of these results, idiopathic salivary hyperamylasemia was diagnosed. One and a half years later, serum levels of salivary amylase are still high.