Macroamylasemia associated with thyroid cancer, elevated serum thyroxine-binding globulin (TBG), chronic pancreatitis and gastrointestinal polyposis.

A case of macroamylasemia in a 78 year-old female, associated with papillary adenocarcinoma of the thyroid and elevated serum thyroxine-binding globulin was described. Serum amylase of the patient was very high despite a normal level of serum lipase. Her serum amylase was characterized as macroamylase on the basis of electrophoresis and elution profile of gel chromatography. Serum precipitation response using chain-specific rabbit anti-human IgG, IgA and IgM antisera disclosed that her macroamylase was mainly composed of immune complexes between amylase and IgA class anti-amylase antibodies. Both the pathogenesis and clinical significance of the association of these disorders in this patient were discussed.