Porous diaphragm syndrome with recurrent thymoma

Porous diaphragm syndrome describes a defect in the diaphragm in which substances pass from the peritoneal cavity to the pleural space. Defects may be congenital or acquired. Acquired defects are caused by the thinning and eventual splitting of collagen fibres in the tendinous part of the diaphragm. We report a case of porous diaphragm syndrome with recurrent thymoma that presented with massive ascites. Increasing intra‐abdominal pressure by ascites and diaphragmatic thinning due to malnutrition by malignancies resulted in the formation of an artificial hole. Thoracentesis changed the balance of hydrostatic pressure, which initiated the influx of a large volume of ascites to the pleural cavity through a hole in the diaphragm.