A form of amylase with a molecular weight much greater than ordinary amylase. The macroamylase molecule is too large to be excreted by the glomerulus of the kidney. It is clinically important because its presence in the bloodstream may falsely suggest the diagnosis of pancreatitis. In patients with macro-amylasemia, the urinary amylase would be within normal limits, which would not be true if the elevation of blood amylase were due to an increase in pancreatic amylase.