Renal cysts. II. Chemical and dynamic study of cystic fluid.

The chemical analysis of the fluid obtained by puncturing 100 simple renal cysts in adults show that the composition of cystic fluid resembles that of interstitial fluid. The chemical balance between cystic fluid and the interstitial space seems to occur passively. Antibiotics which were given orally (amoxycilline, minocycline, rifampicin) do not pass through the wall of a simple cyst. Study of the permeability of the cyst wall did not show any uptake of radioactive hippurate or radium pertechnetate.