Massive hydrothorax occurring during continuous ambulatory peritoneal
dialysis is a rare complication that may appear at any time during the
course of the treatment. Most of the time, it is right-sided and is m
ore frequent in female patients. A case is presented that was investig
ated by peritoneopleural scintigraphy. A rapid accumulation of the rad
iopharmaceutical over the right hemithorax was observed. To explain th
at finding, a macroscopic diaphragmatic defect was suspected. Differen
t therapeutic approaches are presented.