A pancreatic disease associated with right hydrothorax is extremely rare. We have experienced a patient complaining of dyspnea due to right massive collection of hemorrhagic pleural fluid, who was strongly suspected of pancreatic hydrothorax from the elevated amylase level in the pleural fluid. Surgical treatments including pancreatic drainage and closure of the fistula opened to the pleural spaces on laparotomy could yield a cure for the patient.
The patient, a 54-year-old man, had medical histories of left thoracic trauma and hemothorax 10 years ago, and one year after that, he had operated on for chronic pancreatitis, cyst of the pancreatic tail, and gastritis phlegmonosa at another hospital. Though we could hardly find any abdominal symptoms or findings, a fact that amylase fraction was type P led to the diagnosis of pancreatic hydrothorax.