Pancreatic hydrothorax is characteristically more common on which side?

• A. Left
• B. Right
• C. Bilateral equally
• D. Superior

Answer: (A)

Pancreatic hydrothorax occurs when pancreatic secretions leak into the pleural space through a transdiaphragmatic fistula or via diaphragmatic or lymphatic channels. The left pleural space is most commonly involved because the pancreas, especially its tail, sits adjacent to the left hemidiaphragm and can track directly into the left pleura through small defects or openings in the left diaphragm. The liver and the anatomy of the right diaphragm make right-sided involvement much less likely. As a result, left-sided pleural effusions with high amylase content are the classic presentation.