Marked hyperamylasemia associated with carcinoma of the lung

We present a case of marked hyperamylasemia associated with undifferentiated small cell carcinoma of the lung. The serum alpha-amylase had an electrophoretic mobility similar to that of salivary gland enzyme (s-type), and that in tissue extracts from the lung tumor and metastatic skin nodules showed similar migration. No evidence of a salivary or pancreatic cause of hyperamylasemia was found at autopsy, and macroamylasemia was excluded. We suggest that the strikingly increased serum alpha-amylase activity was a result of ectopic production of this enzyme by tumor. We compare results for this case to other published reports.