Aspiration with amylase determination in differentiating pancreatic from renal cysts.

Cyst puncture has become a valuable diagnostic tool in the management of renal masses considered to be cystic by ultrasound. A case is reported of a mass that was considered to be a renal cyst after urographic, sonographic and angiographic examination. However, the correct diagnosis was made by determining the amylase content of the aspirated fluid.