A RARE CASE OF ECTOPIC ANTIDIURETIC HORMONE-PRODUCING PANCREATIC ADENOCARCINOMA - NEW DIAGNOSTIC-APPROACH

We describe a 73-year-old man with the syndrome of inappropriate antid iuretic hormone secretion (SIADH) due to an ectopic ADH-producing panc reatic adenocarcinoma. His laboratory findings showed marked hyponatre mia, and the water load test showed uncontrolled ADH secretion. The im aging studies revealed pancreatic body cancer. Histological examinatio n revealed an adenocarcinoma of the pancreas, which was positive for A DH immune-staining. The ADH in the tumor extract was 53.3 pg/g wet wei ght. In attempt to diagnose ADH-production from the tumor, the ADH in his pancreatic juice was measured and found to be 2.1 pg/ml. We conclu de that it is valid to measure the ADH in pancreatic juice to diagnose ectopic ADH production by tumors.