A case of amylase-producing lung cancer

A case of lung cancer with hyperamylasemia was studied. Small cell carcinoma was diagnosed histologically. The salivary gland and pancreas had no clinical involvement in the hyperamylasemia. Saliva-type amylase was dominant as observed from amylase isozyme patterns in the serum and tumorous tissue. Levels of amylase were higher in tumorous tissue than in normal lung tissue. Immunohistochemical study showed amylase localized in tumor cells. Observation of the ultrastructure revealed electron-dense granules in the cytoplasm of the tumor cells. Findings suggested that amylase was being produced by the lung cancer in this case.